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Severe abrasive wear of drill pipe and casing often occurs in exploration drilling operations. To achieve the surface enhancement of the drilling components in terms of abrasive wear resistance, various flux-cored wires (FCWs) containing multiple alloying elements were developed, and the Fe-based hardfacing layers were developed by metal active-gas (MAG) welding process. The macro morphology, microstructure, and phase composition of the alloys were characterized by using OM, SEM, XRD, and EDS methods, while the wear resistance performance was measured by using an abrasion tester. The results showed that the hardfacing layer prepared by Fe-Cr-C FCW is hypoeutectic that mainly consisted of austenite matrix and (Fe,Cr)7C3-type carbides. On this basis, a higher C content in combination with Nb, Ti, and B additives resulted in the microstructure comprised of martensite-based matrix and the precipitations of (Nb,Ti)C and Fe2B hard phases. With the removal of Cr, the further addition of Nb, Ti, and B, the hard phases change from particles to bulk and lath shapes. The hard phases with higher microhardness values than the matrix contributed to an improved Rockwell hardness and a highly decreased wear weight loss of hardfacing layer. Accordingly, the wear mechanism changed from severe plastic fracture to micro-cutting going with a slight brittle micro-peeling. The interlaced distribution of (Nb,Ti)C and Fe2B provided a stable skeleton that enables an further enhanced abrasive wear resistance.

Mo2(Fe,Ni)B2-based cermets were successfully prepared by reaction boronizing sintering strategy, and their phase transformation, microstructure evolution, mechanical properties, and corrosion resistance were investigated. Mo2(Fe,Ni)B2 was formed by the reaction between (Fe,Ni)2B and Mo during solid-phase sintering. In the temperature range of 1010–1270 °C, extremely rapid densification occurred, and nearly full densification was obtained at the sintering temperature of 1270 °C. Mo2(Fe,Ni)B2-based cermets demonstrated superior mechanical properties with transverse rupture strength of 2140 ± 35 MPa, Rockwell hardness of 83.9 ± 0.1 HRA, and fracture toughness of 22.5 ± 0.6 MPa m1/2. Moreover, corrosion current density of Mo2(Fe,Ni)B2-based cermets was about four orders of magnitude lower than that of Mo2FeB2-based cermets, which indicates excellent corrosion resistance.

The effect of the axial static magnetic field (ASMF) on cleanliness and microstructure in magnetically controlled electroslag remelted GCr15 bearing steel ingots was investigated experimentally. The results show that a magnetically controlled spin-vibration induced by the interaction of the ASMFs and the remelting current exists at the consumable electrode tip, resulting in thinner liquid melt film and smaller droplets. With the increase in magnetic flux density, the optimization effect of ASMFs on electroslag remelting process increases and reaches the peak with a 40 mT ASMF, then decreases. The cleanliness of the ingots was improved, and the count of inclusions larger than 5 μm was reduced. The microstructure of the ingots processed with a 40 mT ASMF was significantly refined. The depth of the metallic molten pool was reduced from 45.2 to 17.5 mm with the application of 40 mT ASMF. The tensile strength, impact toughness, and Rockwell hardness of the ingots obtained under the 40 mT ASMF were significantly improved. The mechanisms of the spin-vibration occurring at the electrode tip end were interpreted in detail to elucidate the effect of ASMFs.

The mechanical and physical characteristics of gray cast iron are intricately bound to its application as an essential material in manufacturing various goods. SMAW (Shielded Metal Arc Welding) is the most simple and widely used electric arc welding method. In this work, ASTM A48 gray cast iron Class 40 was joining using the SMAW method with the welding position used was 1G or underhand position. The joining used is the Butt Joint using an open Singel V seam with a current of 120A. The joining of Welding was characterized through dye penetrant and hardness tests. Rockwell hardness tests on base metal and heat affected zone reveal that the heat affected zone has the highest hardness value of 56.5 HRC, while the base metal has the lowest hardness value (41 HRC). Graphite, pearlite, and pearlite were all visible in the microstructure study.

The present study evaluates the process activation energy or thermal diffusion activation energy (TDAE) to understand the aging kinetics or transformation kinetics. AA7075–5 Vol.% of SiCp composite were fabricated through stir casting technique. Differential scanning calorimetry (DSC) was carried out at different heating rates to understand the precipitation sequence and evaluate the process activation energy or thermal diffusion activation energy (TDAE) of composite. Rockwell hardness tests investigated the aging behavior of AA7075–5 Vol.% of SiCp composite. Results show incorporation of SiCp in the matrix does not affect the sequences of formation and dissolution of precipitate but affects the kinetics of precipitation growth. The formation of precipitation in the alloy and composite requires an access amount of vacancies; an increase in dislocation density may result in heterogeneous nucleation of precipitation and create free path for the kinetically faster atomic transportation of precipitates. Hence, incorporation of SiC particles in the composite would offer a lot of nucleation sites for precipitate, resulting in lower activation energy to form precipitates and takes less time to reach the maximum hardness. In contrast, the addition of a lesser volume fraction of SiCp also showing accelerated aging phenomena in the composite during the aging process. The hardness profile shows hardness increases 3.86% compared to the base alloy AA7075. High-resolution transmission electron microscope (HRTEM) micrograph of peak age (T6) condition divulges that enormous fine and plate-like ή (MgZn2) precipitates are uniformly distributed in the composite.

In order to effectively improve the environmental problems caused by steel slag stacking, the air-quenching process of molten steel slag was carried out, and the properties of the air-quenched steel slag (AQSS) has been investigated by various characterization methods. The results show that the main phases of AQSS were Ca2SiO4, RO phase (solid solution formed by MgO, FeO, and MnO) and Ca2Fe2O5. The AQSS met the technical requirements of a sandblasting abrasive. In addition, the Rockwell hardness of the AQSS with particle size of 1.0–3.0 mm exceeded 50.00 HRC. The particle size of 1–2.5 mm was particularly adapted to use as a sandblasting abrasive. It is clear that AQSS can be used as a sandblasting abrasive by analyzing and comparing the particle size and hardness of the AQSS and commonly used sandblasting abrasives.

Joining of aluminum alloy AA6061 to mild steel was achieved using a friction stir extrusion (FSE) method in which processed aluminum was extruded into a preformed steel dovetail groove. These joints were subject to various in-process cooling (IPC) methods via compressed air, water, granulated dry ice, and liquid nitrogen as well as varying weld pitches (WP) via the following rotational and translational (inches per minute, IPM) weld parameters: 1500RPM-3IPM, 1500RPM-2IPM, 1000RPM-3IPM, and 1000RPM-2IPM. Rockwell hardness testing and lap shear tensile testing were then used to evaluate the effectiveness of IPC by comparison to uncooled joints. These tests revealed an increase of 4.1% and 3.1% of hardness performance of the water cooled and dry ice cooled respectively compared to the uncooled weld. Additionally, the average tensile shear joint strength increased at a maximum of 4.5% for water cooled joints, 3.7% for air cooled welds, 3.5% for dry ice cooled welds, and 1.8% for liquid nitrogen cooled welds. The use of various IPC sources also revealed that the higher the WP, the stronger the extrusion joint. Thus, WP (revolution per inch, RPI) in order of descending performance are as follows: 750 RPI, 500 RPI, and 333 RPI. The novelty of this IPC and WP research comes from the investigation on the FSE joints compared to past research that has used butt and lap welds. The introduction of IPC and varying WP improved the strength and hardness of the FSE joints with the water cooling yielding the greatest measured improvement.

Here, the investigation is spotlighted on the aluminium alloy from the waste materials of the automobile bumpers which is a reinforced metal matrix composite created with 5 percentage of nickel and 5 percentage of magnesium oxide through the stir casting method. The stir casting process inputs parameters such as pressure of squeezing, time of squeezing, and speed of stirrer which were optimized based on the two mechanical properties’ outcome such as the tensile strength (TS) and Rockwell hardness. There are nine different experiments which were conducted based on the L9 array. The Taguchi method is used to identify the optimum input values for the greatest result of the processing condition by Minitab software. The responses-based parameters were ordered based on the rank identified through the investigational effects. Finally, the optimized input consideration values and the linear equations are recommended for both the considered outputs as conclusions.

Hand tooling represents a sizable cost in many industries, which is often exacerbated by premature tool failures. Prevention of these failures is a cost-saving strategy that can be applied to industrial as well as personal projects. The present study employs an integrated theoretical, experimental, and computational approach to investigate the failure of a socket drive adapter of unknown material after being subjected to unknown torsional loading. The failure surface was first compared against a torsion-tested chromium-vanadium adapter using scanning electron microscopy, and it was determined that a torsional overstress caused ductile shearing around the periphery of the adapter, until the smaller cross-sectional area allowed a smaller, non-torsional load to induce a final tensile failure. Results obtained from optical emission spectroscopy and Rockwell hardness test indicated that the failed adapter was likely made from AISI 1025 or a similar grade mild steel, which had been extensively cold worked and/or heat treated during the production process to improve its strength. Finite element analysis was then used to confirm the validity of theoretical calculations for maximum stress at the failure location. The approximate failure load was finally estimated via a strength-hardness correlation, with a conservative estimate for allowable torque of as little as 10.6 N m. The method presented in this paper shows that the load applied on hand tools in everyday use can be too high and can cause failure. The quality of the hand tools plays a key role in determining the amount of load that the hand tools can withstand.

Composites are a class of materials that give the desired individual tribological and mechanical characteristics. In composite materials, more than two materials are combined to provide a unique combination of properties. This article describes the tribological and mechanical properties of Al6061 reinforced with Al2O3, found experimentally. This article describes the preparation of Al6061 composites with 5 % Al2O3 (size 50 microns) by stir casting process. The hardness of Al6061 with and without amplification was found out with the help of Rockwell hardness tester for 10 seconds at a load of 100 kg. It was found that the hardness of Al2O3 reinforced Al6061 increases compared to unreinforced Al6061. The characteristics related to wear of Al6061 and the new composite material Al6061+Al2O3 were studied. The “pin on disk” method was used with the variation of load varying from 5N-200N and a speed range of 200-1500. An analysis of the sensitivity of key parameters such as load and speed is also described. The results show that the newly developed composite material has a lesser specific rate of wear.

The main objective of this work is the fabrication of functionally graded aluminum ceramic composite (FGACC) using centrifugal casting and to study its physical and mechanical properties. LM6 aluminum alloy and silicon nitride (Si3N4) are mixed to form FGACC. This enables the material to have the best of both materials. Si3N4 is varied in size of 30 and 3 µm and volume fraction of 8% and 12%. Centrifugal casting was carried out based on L4 orthogonal array. The gradual change in the distribution of reinforcement of the casted FGACC is ensured using optical microscope SEM and hardness. Image Analyser software was used analyze the volume fraction of phase and grain size for all FGACCs. It was observed that the Si3N4 concentration increases from the inner to the outer periphery of the casted ring. This is due to the radial forces generated from centrifugal casting to segregate a second discrete phase from the matrix of composite materials. Rockwell hardness values increased from the inner to the outer region ensuring the gradual increase in Si3N4. Hardness increased by 30 and 22% in outer for 3 and 30 µm. Archimedes principle was used to find the density based on which the porosity was calculated. Porosity values were 1.8% in the outer region and 2.97% in the inner region. SEM images were also used to characterize the FGACC. ANOVA was done to find the most influencing parameter on hardness. R2 value for the outer region was 99.24%, indicating that the developed model is accurate and fits very well with experimental values.

In this work, nanocellulose (NC) was prepared by a new route consisting of dissolution of cellulose in phosphoric acid followed by regeneration in water. To facilitate the dissolution, the cellulose was pre-treated with aqueous solution of urea. Although the regenerated cellulose from water had been in nanoscale, its size could be further reduced through ball milling. The composition, structure, and morphology of the materials from different preparation stages were studied by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. NC was then incorporated into the HDPE based wood-plastic composites (WPCs) in a skillful way to guarantee its good dispersion. The influence of addition content of NC on the mechanical and thermal properties of WPCs was investigated comprehensively. WPCs incorporated with NC exhibited an obvious increase in impact strength compared with those without NC. In addition, the Rockwell hardness, Vicat softening temperature and thermal stability of WPCs incorporated with NC were also correspondingly improved. The effect of ball milling on the size of nanocellulose was also investigated. The application results showed that the NC prepared without ball milling was more efficient in enhancing the toughness of WPCs.

In this research, the nitride titanium layer was deposited on AISI 316L stainless steel and the adhesion of the optimum layer had been evaluated. The electrophoretic deposition process was carried out with optimum composition and under the variation of diverse voltages of 20, 25, and 30 V and time of deposition of 3, 5, 7, and 10 min. Sintering at 1200°C within 2 and 4 h was applied on the achieved nitride titanium coatings to improve adhesion of the layer. The obtained layers were characterized by X-ray diffractometry and scanning electron microscopy. Results show that the sample achieved at 25 V within 5 min has uniform layer on the surface of the substrate. Adhesion strength was evaluated by performing Rockwell C hardness test according to VDI 3198 guideline on the optimum sample with uniform layer and the crack propagation was studied by using SEM. Results show that although there is a ductile feature of the layer in macroscale, it has brittle feature in microscale and acceptable adhesion strength of as-sintered sample.

In the present work, the microstructure and mechanical properties of microwave welded Al6061-6%Graphite-SiC hybrid metal matrix composites (MMC) were investigated. The microwave welding was carried out using the principle of microwave hybrid heating and Al6061 powder as an interfacial material. The domestic microwave oven having the frequency of 2.45 GHz and 900 W power was used for the experiments. The charcoal powder as a susceptor was used during the welding process. The hybrid MMCs Al6061-6%Gr-SiC were developed through stir casting process with different weight percentage of SiC keeping graphite constant. The joints were characterized using x-ray diffraction, scanning electron microscope (SEM) equipped with energy-dispersive spectrum (EDS), Rockwell hardness tester and universal testing machine. The x-ray diffraction analysis showed the presence of harder aluminum carbide and aluminum oxide phases. The microstructural study revealed the good metallurgical bonding between the interfacial composites with absence of cracks. The elemental analysis of joint revealed the presence of aluminum, carbon and oxygen with other elements. The average ultimate tensile strength of the microwave joints was recorded as 135 MPa with 4.3% elongation. The average Rockwell hardness at the weld joint observed was 61.5 ± 5 HRB. The evaluation of mechanical properties of microwave welded composites indicated the increase in the tensile strength and hardness as the content of SiC reinforcement increased. The joint strength found to be 65.15% of parent composite, which is similar to the joint strength of welded aluminum-based composites by various techniques such as friction stir welding, laser beam welding, electron beam welding, etc. The present investigation has showed that the microwave energy can be used successfully, as an alternative method to weld the composites.

Brake pads are generally made of asbestos, which is less environmentally friendly and widely available in nature, therefore motorcycle brake pads are made that utilize palm frond fibers filled with alumina powder and bonded to a polyurethane matrix. This research was conducted at the Laboratory of Material Testing of Industrial Chemical Technology Polytechnic (PTKI) Medan. Research was carried out from February-July 2020, using two test, namely the Rockwell Hardness level test and the Pin On Disk Friction Coefficient test. The result showed that oil palm frond fibers can be made into motorcycle brake pads with the addition of alumina powder according to the predetermined composition. After going through the test, the Rockwell hardness level was obtained in A2 treatment (6% Alumina) with the highest and best hardness level, namely 52.75 Kg. And after testing the friction coefficient of the Pin On Disk type, brake pads from palm frounds with the addition of alumina powder composition which have the lowest coefficient value of the best are obtained in treatment A2 (6% Alumina) with a value of 0.000765 N/mm 2 . Keywords : biocomposite, brake shoes, palm fround fibers, alumina powder

The selection of the optimal external cylindrical grinding conditions importantly contributes to increase of productivity and quality of the products. The external cylindrical grinding is a method of finishing machine elements surface with an indeterminate blade shape. External cylindrical grinding can process surfaces that require high gloss and precision, although it can also be used to remove large surplus stock. Therefore, multi objective optimization for the external cylindrical grinding process is a problem with high complexity. In this study, an experimental study was performed to improve the productivity and quality of grinding process. By using the experimental date, the surface roughness, cutting force, and vibrations were modeled. To achieve the minimum value of surface roughness and maximum value of material removal rate, the optimal values of external cylindrical grinding conditions were determined by using the combination of Genetic Algorithms (GAs) and weighting method. The optimum values of surface roughness and material removal rate are 0.510 μm and 5.906 mm2/s, respectively. The obtained optimal values of cutting parameters were a feed rate of 0.3 mm/rev, a workpiece speed of 188.1 rpm, a cutting depth of 0.015 mm, and a workpiece Rockwell hardness of 54.78 HRC. The optimal values of cutting parameters, and workpiece hardness were successfully verified by comparing of experimental and predicted results. The approach method of this study can be applied in industrial machining to improve the productivity and quality of the products in external cylindrical grinding process of the T1 tool steel

The paper presents investigations of the structure, phase composition and properties of the rail running after bulk steel hardening. Investigations are performed at a different depth by using modern techniques of material physics in extremely long operation conditions (gross weight of 1411 million tons). The Rockwell hardness measurements at a depth ranging from 2 to 10 mm, show a decrease in the hardness level from 37.1 to 35.8 HRC and in the microhardness – from 1481 to 1210 MPa, respectively. The multiple modifications of the rail running surface include the disintegration of lamellar perlite and the formation of the submicron size subgrain structure varying between 100 and 150 nm; the formation of 30–55 nm carbide phase nanoparticles on the grain boundaries and in the subgrain volume; the growth in microdistortions and the crystal lattice parameter of the α-Fe solid solution; the increase in the scalar dislocation density. Possible reasons of these changes are discussed herein.

In order to elucidate the relationship between red hardness/toughness and tungsten content, strong carbide-forming element tungsten was added to a 5 wt.% Cr medium carbon steel (Cr5) in melting. After normalization and forging, the vacuum gas-quenched experimental steels were tempered at 560 and 600 °C for 10-40 h, respectively. Rockwell hardness and un-notched impact energy were evaluated. It was revealed that the precipitation phases play a critical role in the mechanical properties of the steels. The tungsten element effectively improved the red hardness of the steel by 6.3-15.8% when tempering at 600 °C for 10-40 h, while the corresponding impact toughness holds at the same level, about 250J, as Cr5 steel. Through observations by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), mesoscales carbides were found with a structure of (Fe, Cr, W, Mo, V)6C. It was deduced that tungsten element acts a positive role in inhibiting the coarseness of secondary M6C-type carbides and impeding the formation of M23C6 and M7C3, and thus enhances the thermal stability of Cr5W steel at elevated temperature. Furthermore, the tempering stability prediction model was constructed to predict the red hardness of tungsten-containing Cr5W steel.

Improving the surface quality after burnishing operation has been the subject of various published investigations. Unfortunately, the trade-off analysis between the energy consumption and surface characteristics of the internal burnishing has been not addressed due to the expensive cost and huge efforts required. The objective of the present work is to optimize burnishing factors, including the spindle speed, burnishing feed, depth of penetration, and the number of rollers for minimizing the energy consumed in the burnishing time, as well as surface roughness and maximizing Rockwell hardness. An adaptive neuro-based-fuzzy inference system (ANFIS) was used to develop burnishing objectives in terms of machining parameters. The optimization outcomes were selected using an evolution algorithm, specifically the non-dominated sorting particle swarm optimization (NSPSO). The results of the proposed ANFIS models are significant and can be employed to predict response values in industrial applications. The optimization technique comprising the ANFIS and NOPSO is a powerful approach to model burnishing performances and select optimal parameters as compared to the trial and error method as well as operator experience. Finally, the optimal solution can help to achieve the improvements in the energy consumed by 16.3 %, surface roughness by 24.3 %, and Rockwell hardness by 4.0 %, as compared to the common values.

Silver has wide-ranging applications, such as industrial equipment, semiconductors, musical instruments, and silverware. Despite its diversified applications, publications on its strain-hardening characteristics are rare. In this work, tensile and hardness tests were performed for cold-rolled specimens at different levels of thickness reduction after full annealing. Up to the true strain of 1.7, strain-hardening characteristics and variations in Rockwell hardness were obtained for 99.9% pure silver. The consistency between the true stress–strain curve and the hardness data was confirmed through finite-element modeling and analysis of the hardness test procedure. Strain-hardened pure silver was verified to have yield strength comparable to sterling silver. For applications where both of purity and deformation resistance are important, strain hardened pure silver could be a practical candidate.

Aluminum-based metal matrix composites (MMC) are very popularly used in the aircraft, automotive, and armament industries because of their high young’s modulus, specific strength, and enhanced wear properties. In this research, Al6061/SiC composites are produced using the powder metallurgy technique by varying Wt.% SiC (0, 5, 10 and 15) and sintering duration (1, 2 and 3 h). The effect of SiC Wt.% and sintering durations on the composites properties are examined using a scanning electron microscope, Rockwell hardness test, and Charpy impact test. Both Wt.%SiC and sintering duration substantially impacted Al6061/SiC composites mechanical properties. The morphological study of 15Wt.%SiC composite sintered for 3 h confirms the absence of microcracks and SiC clusters with good interfacial bonding between Al6061/SiC. It is observed that long sintering duration stimulated thermally activated diffusion-controlled grain growth, which adversely affected the mechanical properties and rendered superior characteristics that are otherwise impossible. The hardness and toughness of composite increased from 73 to 81 HRB and 3.2 J to 5.2 J, respectively, under the best process conditions.

Tantalum and palladium were added to Inconel 718 at the expense of Nb content to study resultant microstructure and mechanical properties in hot-worked and annealed condition. An increase in {100} peak intensity along with a concomitant decrease in {111} peak intensity was observed with decreasing Nb content. Ta-containing alloys exhibited annealing twins and annealing twin density showed a direct relationship with Ta content. Overall, alloying additions improved strength as well as ductility except the alloy containing only Ta which was less strong than Inconel 718. The alloy containing Ta as well as Pd exhibited highest toughness and lowest Rockwell hardness value.

The relation between the mechanical properties and the structural changes across the wall thickness is studied for hollow thin-walled castings made of gray cast iron with flaked graphite, which are formed by continuous cyclic freeze casting without the use of a rod. Ultimate tensile strength σu, HB Brinell hardness, HRB Rockwell hardness, and microhardness are determined in the zones of dendritic crystals and eutectic matrix. At the same Brinell hardness, σu of the castings made of the cast iron under study is shown to be significantly higher than that of the castings made of gray cast irons poured into sand–clay molds.

The effects of traditional heat treatment (quenching and then tempering) and deep cryogenic treatment on the microstructure and mechanical properties of a low-carbon high-alloy martensitic bearing steel were studied by Rockwell hardness test, X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite during cooling, which leads to the hardness of the sample after deep cryogenic treatment higher than that at the quenched state. Also, the carbon content in the martensite matrix after different treatments was calculated and the results indicated that deep cryogenic treatment can promote the segregation of carbon atoms in martensite to dislocations. The segregated carbon atoms act as and grow into nuclei for the formation of fine carbide particles during subsequent tempering. And this resulted in the fact that the hardness of the tempered experimental steel after deep cryogenic treatment is higher than that without deep cryogenic treatment.

In this study, the function of rare earth (RE) oxides added in boronizing agents was studied by analyzing not only the boronized titanium (Ti6Al4V) but also the agent materials at 900–1050 °C. XRD results showed that low-melting-point RE borates were formed in the boronizing processes. The existence of the RE borates probably provided a partially liquid boronizing environment for the titanium alloys. By scaling up the boronizing process for larger samples, not only borides but also carbides were formed on the samples indicating a borocarburizing process occurring. The boronized alloys showed excellent mechanical properties (Vickers hardness 1800HV0.1, Rockwell hardness 95–98 HR15Y up to 900 °C, tensile strength 941 MPa, fiction coefficient 0.15, friction bonding strength >300 N) and a good burner rig thermal shock performance (without spallation of surface oxide).

Wear and hardness behaviour of aluminium metal matrix composite is investigated. The matrix is aluminium LM4 and reinforcement is nano alumina and Molybdenum (Mo). The composites were fabricated in different composition by varying the weight fraction of matrix and reinforcement. The reinforcement nano alumina is nano size and Mo is micro sized. The reinforcement alumina varies with 1, 1.5, 2.5 and 5% of weight fraction and Mo was kept constant of 0.5% in all composition. Stir casting method is used to fabricate the composite. Wear test carried out on pin on disc wear testing machine under dry sliding conditions and constant sliding distance and hardness test carried out by Rockwell hardness testing machine. This work mainly emphasis on the variations of hardness and wear properties by varying the reinforcement composition by weight percentage. The wear resisting rate and hardness of the material increased gradually by adding the nano alumina and Mo. Observed that reinforcement 5% of nano alumina, 0.5% Mo with matrix showed that better in wear resistance and hardness.

Polyester non-woven fabrics are a good choice for base material in development of engineered waterproof fabrics. They find wide applications in bathroom floor lining, Roof lining, Car floor lining and many such applications. These fabrics not only provide strength and durability to the structure but also enhance the thermal as well as shelf-life of the structure. The presence of Chemical groups like ethylene functional group which is a chemical compound prominently present in polyester and observation of strong peaks of polyester functional groups aids in robust behaviour of the waterproof coated fabrics. These chemical groups present in the waterproof acrylic polymer binder also influences the development of durable fabrics with good hardness values. In this research a waterproof fabric for such applications is developed using a non-woven polyester fabric as the base material and roller coating process. The changes in the surface morphology of the fabrics is recorded and analysed using SEM micrographs. However, the analysis of thermal properties of these coated fabrics using DSC, TG/DTA instruments show melting of the coated material at 375 °C and TGA graphs show degradation of material occurring at 400 °C. The density measurement results show the fabrics ability to achieve lower values when nonwoven fabric layers are doubled which may be due to consumption of less binder and locking of air between layers. The Rockwell hardness results of 31.4 HRB (B scale) for single layer and 68.2 HRB for double layer proves the performance of the coated fabric at par with soft steel. The coated fabrics show zero air porosity when tested under air-permeability tester. The process of roller coating proves to be robust method of application of water proof polymer binder on non-woven fabrics.

In this experiment, using the Metal Inert Gas welding process we will investigate the mechanical properties of aluminum alloys (AA6063, AA7075, AA2014), and mild steel. MIG is favored since the welding process provides clean welding with better quality and also with reduced slag in the weld. The use of MIG welding to combine dissimilar materials is a new area for weight reduction in power generation, electrical, nuclear, petrochemical, and chemical industries. Because of the thermal, mechanical and chemical properties of the materials, a number of problems will be faced in welding these dissimilar metals through the whole process such as cracking, reduction of strength, porosity, surface quality and stress. Like Mild Iron, aluminum alloys have lower density and better mechanical properties. Because of its lightweight properties these aluminum alloys are used in the aerospace and automotive industries. Dissimilar metal alloys of aluminum 6063, 7075, and 2014 were butt jointed with mild steel respectively using a MIG welding process. The mechanical properties of dissimilar materials were tested by performing the tensile test, the Rockwell Hardness test, the Vickers hardness test, the macro and micro test showing an overall weld quality and a good appearance on the welded region as micro and macrostructure are used to examine the quality and weld zone. Finally, we conclude that from the results of Tensile, Rockwell and Vickers hardness the weldability and strength quality is good in AA6063.

Nowadays the choice of polymer composites are alternative solution of Metal matrix composites for the light weight construction to less cost consumption. The most of the fibers are freely available in surrounding environmental sources. In this work consider the Arecanut and Kevlar fiber with epoxy resins to make a simple plate structures. The Arecanut is the eco friendly material it has 53.2% of cellulose content. The mechanical strength of the composites is analyzed such as tensile strength, Rockwell hardness and the impact test. The different size of the fibers are prepared with adding of epoxy resin for obtain the excellent strength, the denser of the fibers and the applied of resin are decided the strength of the composites. The hybrid composites are implemented to prepare the composites, slightly increasing the thickness of the composites in the preparation that causes increase the strength of the plate. The enhanced hardness value was obtained by using of the epoxy resin for the composites.

In recent scenario, polymer hybrid composites are in growing demand over conventional natural fiber, or synthetic fiber reinforced polypropylene composite in automobile and aerospace industries. These hybrid composites have good properties like light weight, good strength, high stiffness, sound absorbing capacity good creep and flame resistance etc. In this study, natural fiber (NF) has been blended with carbon fiber (CF) to fabricated jute-carbon fiber reinforced polypropylene composites. Compression molding process with volume fraction of 0.20 has been used to fabricate the composite. Jute fibers have been arranged in bidirectional manner to add strength and good surface finish to the composite. For characterization, tensile test, flexural strength test, impact test and hardness test have been investigated followed by water absorption test. It has been observed that stacking sequence of CJC reinforced polymer composite has resulted in maximum tensile strength of 92.336 MPa, Rockwell hardness number 103.65, flexural strength of 44.771 MPa and impact strength of 2.65 ± 0.5 J as compared to JCJ reinforced polymer composite.

The modern manufacturing industry needs highly characterized materials for a variety of applications, which leads the material researchers were focuses on hybridization in the aluminium metal matrix with various reinforcements. In this research investigates the mechanical properties of aluminium alloy Al 6061 with the reinforcement of silicon carbide and eggshell particles in various proportionalities. The stir-casting method is used to prepare the Al 6061 based hybrid aluminium composite material by varying the weight percentage of both silicon carbide and eggshell particles; the reinforcement material of eggshell increases the hardness of the material with least expensive. The Al 6061 based hybrid aluminium metal matrix test specimens were fabricated as per ASTM standards in the water jet machining process. The Al 6061 based hybrid aluminium metal matrix composite was characterized by various mechanical tests such as tensile load, tensile strength, percentage of elongation, yield load, yield strength, compressive strength, impact strength, impact energy and Rockwell hardness. In the tests reveals that performance of the pure aluminium alloy Al 6061 considerably lower value in impact tests. The 8 wt% of silicon carbide with 4 wt% eggshell particles reinforce hybrid aluminium metal matrix composite is performed very well in the tensile, compressive and hardness tests.

With the use of special technological techniques (layer-by-layer spraying, air cooling and substrate temperature control), the technologically complex problem of applying plasma coatings of increased thickness with high adhesive strength has been solved. The difficulty of solving this problem is due to the occurrence of micro-stresses in the coating during spraying, the difference in the values of the coefficient of thermal expansion of the substrate and the coating, the accompanying heating during plasma treatment, as well as the warping of thin-walled parts during spraying. The regularities of the formation of a coating of zirconium dioxide with a thickness of ~1 mm during high-energy plasma spraying of a powder mixture ZrO2 +7% Y2O3 with a spherical morphology of particles have been studied. The structural-phase state of the coating is investigated. It is established that with this method of spraying, a layered hierarchy of the coating is formed with a columnar shape of zirconium dioxide grains in the interlayers. The effect of the plasma flow stimulates the partial phase transformation of the tetragonal phase T-ZrO2 into the cubic K-ZrO2. To study the adhesive strength of the coating, different methods were used: scratch test, Rockwell test and low-cycle fatigue tests. The high adhesive strength of the adhesion of the investigated coating to the substrate is shown since no detachment from the substrate occurred during any type of testing. In sclerometry, the cohesive mechanism of destruction due to microscopes prevails, affecting only the surface layers (5–10 microns thick) of the coating. The Rockwell test demonstrated the best crack resistance score and a sufficiently high plasticity of the coating. Cyclic vibration tests based on 250,000 cycles showed that microcracks are formed at the boundary with the sublayer. The coating of increased thickness can be used both for protection against high-temperature exposure and against mechanical wear of parts in power and aviation engineering.

The present paper reports the fabrication routes along with the recent development in the area of iron based metal matrix nanocomposites. A detailed discussion is done on iron (Fe) metal matrix nanocomposites reinforced with aluminum oxide (Al2O3) prepared using powder metallurgy (P/M) technique. Composites were prepared by sintering in an argon atmosphere in the temperature range of 900–1100°celsius for 1–3 h. Hardness test was conducted on a Rockwell Hardness Tester using 1/8” H scale steel ball indenter. Specimens were tested for wear and corrosion using pin on disc wear and friction testing machine and gamry electrochemical cell. With the addition of aluminum oxide the hardness number reached upto 79 HRH and the wear rate was found out to be as low as 0.3 mm3/Km. It was also revealed that with the addition of aluminum oxide, corrosion protection efficiency was 99.96% and cobalt doping further improved it to 99.99%.

Alumina reinforced zerconia composite materials are attractive structural fabrics, dental and industrial applications that incorporate high hardness and wear resistance, electrical resistance with additional toughness. In this research work Alumina is matrix material and zerconia is reinforced materials. Composites composite material containing different amount of zerconia added to the aluminum oxide i.e. 5%wt, 10%wt and 15%wt and prepared composite materials by using powder metallurgy milling method. The prepared was checked hardness, wear rate, Electrical resistance and Coefficient of linear thermal expansion. Composites are tested for wear intensity with a pin on the disk wear test machine, hardness for the Rockwell hardness tester, electrical resistance for the electrical resistance meter and coefficient of linear thermal linear thermal expansion is for the dilatometer, to analyze the crack propagation of the composite materials after wear by SEM and revealed a fairly uniform distribution of Ultra n-ZrO2 particles with a slight agglomeration. The incorporation of Ultra nano zirconium dioxide particles into aluminum particles lead to produce a aluminum composites with increased mechanical and electrical properties. Aluminum reinforced zirconia Ceramic composites work material are the good surface finish. The surface quality, the dimensional precision has a significant effect and the materials have a useful life.

This article provides the details regarding the fabrication and mechanical properties of hybrid jute/carbon with the addition of fishbone as nanofiller material which has been explored the first time. The mechanical properties were compared with carbon/jute hybrid polymer composite with and without filler material i.e., fishbone. The hybrid reinforced composites with fishbone powder shows improved mechanical properties in comparison to composites fabricated without filler. Tensile strength varies from 34.91 MPa to 140.82 MPa, flexural strength varies from 66.43 MPa to 166.09 MPa, and Rockwell Hardness of the composites varies from 2.9 HRC to 35 HRC, as a function of fiber volume fraction. The tensile test, flexural test, and rockwell hardness are carried out using ASTM standards. Adding the filler in hybrid reinforced composites shows improvement in tensile strength by a maximum of 7.06%. The morphological property of flexural test specimens analyzed by scanning electron microscopy (SEM). It can be concluded, that the addition of bio nanofiller, in unsaturated polyester resin is an auspicious initiative to produce high strength unsaturated carbon /jute hybrid reinforced composite.

In this article, the impact and hardness properties of the epoxy resin matrix, banana fiber-reinforced, and Camellia Sinensis particles, filled bio-composites were established. Four composite specimens for Izod impact test and Rockwell hardness test were prepared as per the ASTM standards by keeping weight percentage of the matrix material as constant (65%) and varying the weight percentage of banana fiber (35, 33, 31, 29%)/Camellia Sinensis particles (0, 2, 4, 6%) respectively. Izod impact test and Rockwell hardness tests are performed on the four composites specimens as per ASTM standards. Experimental results reveal that by adding Camellia Sinensis particles with epoxy resin matrix/banana fiber composites enhances the hardness and diminishes the impact of energy and impact strength of the composites considerably.

In the fabrication of automotive vehicle brake linings, the usages of asbestos create an adverse reaction on humankind and the surroundings. Hence it led to the evolution of organic-based brake lining without using asbestos material. The various types of asbestos-free brake lining materials are developed to create new lining compositions providing effective performance. In our work, the effect of carbon fiber reinforced in brake linings are studied, and their friction performances are examined. The composition of carbon fiber contents are varied by 0%, 5%, 7.5%, and 10% by volume in the total weight of the mixture of brake composites and corresponding brake pads are fabricated. The various physical, mechanical and tribological analyses are performed. The experimental work results revealed that the sample with 10% of carbon content has high tensile strength, flexural strength, Rockwell hardness, and friction co-efficient. Also, the wear test showed a low value for the sample containing 10% of carbon content. The microstructural analysis revealed that the sample having 10% of carbon content has closure packing, which causes the strong bond formation of a matrix with carbon fiber filament.

Electric Resistance Friction Stir welding has been invented as one of the hybrid technologies and produces less tear and wear of the tool with least defects at the produced joint. The study focuses on the Electrical Assisted friction stir welding (EAFSW) of Al6061 alloy. In this experiment an attempt has been made and evaluated to derive the optimum mechanical properties by adjusting the rotational speed, welding speed and current in the range of 500–900 rpm, 10–25 mm/min and 25–75 amps, both in reverse polarity and straight polarity. In the present study, mechanical properties of welded joints using conventional FSW have compared with that of Electrically Assisted Friction Stir Welding (EAFSW) with two different approaches. The rotation speed, travel speed and current were the primary welding parameters which considered. The Rockwell hardness, ultimate tensile strength and weld efficiency of the welded joints were found out for the above-mentioned cases and a comparative study of the mechanical properties have been done. It has been observed that better weld efficiency and hardness has been obtained in Direct Current Reverse Polarity EAFSW. Straight polarity to EAFSW process had been found to decrease the weld efficiency of the joint, whereas, the reverse polarity DC has been proved to be adding weld efficiency in the joint for Al6061-T6 Al alloy.

Due to greater specific modulus, better wear resistance, excellent specific strength, and declined coefficient of thermal expansion value, particulate reinforced aluminum matrix composites have acquired appreciable consideration. Casting route and powder metallurgy are the commonly used fabrication methods from which we select stir casting technique due to its simplicity and low expense. In this study mechanical properties like tensile strength, yield strength, hardness, wear, coefficient of friction (COF) and frictional properties of light metal (LM6), LM6/ Boron Carbide (B4C) and LM6/B4C/Graphite (Gr) 2% were analyzed with the aid of Universal Testing Machine (UTM), Rockwell Hardness Tester and Pin on Disk Tester. B4C was chosen due to its excellent reinforcement properties compared to silicon carbide (SiC) and alumina. Gr (2%) was added in one sample to obtain better tribological as well as better sliding lubricating characteristics. The test outcomes reveal that by increasing the percent of B4C particles in the LM6 matrix, the mechanical as well as tribological properties are improved and the new material developed can replace conventional LM6 aluminium alloy in its applications.

The main reason for this work is to prepare aluminum metal matrix composite with vermiculite in an attempt to enhance it is mechanical and wear properties. Three compositions were selected along with Al6063, they are Al2%ver (98% Al6063 and 2% Vermiculite), Al5%ver (95% Al6063 and 5% Vermiculite), Al10%ver (90% Al6063 and 10% Vermiculite). The stir casting technique is chosen to create this component due to its low cost, simplicity, and it also used to mass production. Tensile, Rockwell Hardness, wear, Optical microstructure, and Charpy impact test of the prepared composites was analyzed. The tensile strength was found to be more in Al5% vermiculite, The hardness values indicate an increase in the hardness is higher in Al2% vermiculite. The Tribological studies show that the wear properties of the specimen were higher in pure aluminum. It was clear from the tests that the addition of vermiculite (ver) enhances the tribological and mechanical properties of the reinforced Al6063. The microstructure analysis confirms the uniform dispersion of the reinforcements in the matrix. This is achieved when the stirring parameters are chosen appropriately and the results were discussed in detail.

In this study, the hardness values were analyzed to compare the micro-alloying (0.02 and 0.04 wt%) effect of Titanium (Ti) in 2xxx series Aluminium (Al) alloys. Al-Cu-Mg (alloy-A), Al-Cu-Mg-0.02Ti (alloy-B) and Al-Cu-Mg-0.04Ti (alloy-C) were the alloys which were prepared using standard casting process. Different conditions of heat treatment were applied on the alloys. Using Rockwell Hardness tester hardness was investigated for the said alloys under as-cast and heat treated conditions. Addition of 0.02 wt% of Ti to the investigated alloy improves the hardness value by about 3.61% when the alloy was naturally aged and water-cooled (NAW). After adding 0.04 wt% of Ti to the investigated alloy improves the hardness value by about 15.66% when the alloy was naturally aged and water-cooled (NAW). In the study the hardness values were recorded for 31 days at different time intervals such as at Day 1, 7, 15, 21 and 31. The hardness of the alloys was maximum when it reaches Day 15 and gradually decreases after that. The hardness of the water-cooled samples (Alloy A, B and C) was seen to be decreasing in a specific order in all the days the hardness test was performed. The order observed is, NAW > AC > AAW > NAWSH > NAWS > AAWH.

High silicon stainless steel which are subjected to age hardening are mainly used as structural materials in power plants and chemical plants due its properties of high hardness and resistance against corrosion and wear. The present study explores the impact of high and low silicon content in stainless steel on the mechanical and corrosion properties and also the possibility to change the both low silicon and high silicon content stainless steel mechanical properties, corrosion resistance and wear resistances by Selecting the heat treatment conditions i.e., age hardening with aging time for 2–6 h at 300 °C after solution heat treatment at 900 °C for 1 h. Mechanical properties, wear and corrosion opposition are observed to be better in high silicon content stainless steel. The ultimate tensile strength (Mpa) obtained from result using UTM and hardness (HRB) result obtained from Rockwell hardness tester showed a peak at intermediate aging time than low and high aging time in both low and high silicon content stainless steel and The wear rate and corrosion rate of the both high and low silicon content stainless steel are minimum at least aging time and the result are analysed based on the microstructure developed on heat treatment for various durations.

The objective of this research is to determine the effect of heat treatment on the mechanical properties of mild steel. Annealing, normalizing, and hardening are the most important heat treatment processes often used to improve the mechanical properties of engineering materials. The main reason behind heat treating materials is to determine the mechanical properties such as ductility, hardness, yield strength, tensile strength, and toughness and to improve the machining to make them more versatile. In this experiment, the specimens were first machined according to ASTM standard and then were heat-treated at a certain temperature above the austenitic region and were hardened in both salt solution and tap water. Tensile Test, Rockwell Hardness Test, and Finite Element Analysis (FEA) were performed on the heat-treated specimens to determine the final results. The maximum hardness and tensile strength were obtained in hardening process as compared to annealing and normalizing.

Nowadays, composites are profoundly thriving as the replacement of ferrous alloys. The Aluminum manifested into a great substitute due to its properties like lightweight, low density, high strength, and corrosion resistance. The process of fusing the non-ceramics reinforcement like Silicon carbide, Boron carbide, Aluminum oxide, Titanium diboride with a non-metal like Graphite, Molybdenum disulfide or with other non-ceramic to form a hybrid metal matrix composite. In the present paper, an investigation carried out on Aluminum 7075 material by the process of stir casting where the Silicon Carbide (SiC) with three different weight % (i.e., 3%, 6%, 9%) and Molybdenum Disulphide (MoS2) with 1% constant weight % added to the base material. The tensile test and hardness test were then done on a UTM and Rockwell Hardness testing machine, respectively, for all three prepared materials. As the percentage of SiC increases in the material, the hardness value and tensile strength are increasing. The Al7075 + 9%SiC + 1%MoS2 is the highest of all.

The heat treatment and quenching process provides tremendous advantages for the steels by modifying the mechanical properties and affecting phase change in the structure of steel. So we perform this heat treatment process in various quenching medium to test the EN8 steels. Few specimen of EN8 steel were studied and analyzed after heating them in the Muffle Furnace between 750 °C and 950 °C followed by quenching in different medium. Oil, Water, and Air are used as different quenching medium. Using the Rockwell hardness equipment the mechanical properties such as hardness are measured, and the hardness of the quenched material is significantly greater than the parent material. The samples are then subjected to Charpy impact testing and Rockwell hardness testing after heat treatment. The sample was crated for Charpy test as per ASTM-E23, and for Rockwell hardness test as per ASTM-E18.In this work EN8 a grade of medium carbon steel is used. The composition of this EN8 steel is shown in the table below. The specimen was taken in the form of square bars 14 × 14 mm cross section which was then machined on lath machine by facing to the cross section of 10x10 mm and then cut. The final dimension of the specimen was 10x10x55 mm as per ASTM-E23. A U - notch of 2 mm depth was cut at the centre for impact testing.

The main purpose of this work is to prepare Aluminum metal matrix composite in an attempt to improve it’s mechanical, electrical and wear properties. To achieve this objective, three compositions were selected. Al 6063H9, Al-2percent Graphite, Al-4percent Graphite and Al-6percent Graphite. Among various fabrication techniques available for the preparation of Aluminum metal matrix composite, Stir casting was chosen due to its simplicity, low cost and it can be used for mass production. Tensile test, Rockwell hardness test, Impact test, wear test, Optical microscopy and Electrical Conductivity test results of the prepared composites were analyzed and test results were compared with Al 6061 specimen. The Tensile test shows that the tensile strength of the material is higher than that of the unreinforced material. The hardness values indicate increase in the hardness with increase in the percentage of reinforced particles. The tribological studies show that the wear properties of the specimen were improved with addition of reinforcements and the same with electrical conductivity test. It was clear from the tests that the addition of Graphite enhances the tribological, mechanical and electrical properties of the reinforced Al alloy. The microstructure analysis confirms the uniform dispersion of the reinforcements in the matrix. This is achieved when the stirring parameters are chosen appropriately.

A novel chromium carbide–nickel composite was in situ fabricated through pressureless sintering in a vacuum furnace using Cr, C, Ni and Mo mixed powders. In this study, the Mo content distribution on interface characterization including the effect of phase transformation mechanism and mechanical properties of the composite were researched thoroughly. The results indicated that a newly found and excellent semi-coherent boundary existed between Cr3C2 and Ni, which was (002)Cr3C2//(11 1 ( _ ) )Ni, [1 2 ( _ ) 0]Cr3C2//[011]Ni. Their disregistry along the particular orientation relationship was approximately 10.6%, indicating that Cr3C2 could serve as an efficient heterogeneous nucleation area of Ni. An interdiffusion and phase transformation occurred in the microstructure, Mo element tended to solid solute into the carbide matrix which changed from (Cr, Ni)3C2 to (Cr, Mo)3C2, and (Cr, Mo, Ni)7C3. Moreover, according to DFT calculation for contain phases as well as the Rockwell hardness, bending strength, and fracture roughness were enhanced simultaneously, it was attributed to grain refinement, solution strengthening, and better mechanical properties of the (Cr, Mo, Ni)7C3 phase.

Severe plastic deformation leads to cementite decomposition in pearlitic and martensitic alloys, resulting in high-strength nanocrystalline ferrite. This effect can be employed to strengthen pearlitic wires but it can also be associated with material failure by white etching cracks (WECs) that are primarily known to concern bearings or rails. We investigate the decomposition of spheroidal cementite in the martensitic bearing steel 100Cr6 with 62 Rockwell hardness during high pressure torsion at 9.5 GPa applied pressure. The hard martensitic matrix and the even harder spheroidal cementite precipitates behave plastically very differently. The enforced macroscopic plastic deformation is almost entirely carried by the matrix. Plastic material flow of the matrix around the spheroidal cementite leads to wear of the spheroidal cementite as indicated by continuously increasing levels of chromium in the matrix. Plastic deformation of spheroidal cementite via dislocation gliding supposedly accelerates this process as slip steps generated thereby are preferential sites of wear at the matrix/cementite interface. Larger spheroidal cementite precipitates are more prone to plastic deformation and to decomposition than smaller ones. The mechanism likely holds true in general for multiphase materials with large strain difference between phases subjected to high pressure torsion. Although the formation of WECs in 100Cr6 bearings might be slowed down by reducing the size of the spheroidal cementite precipitates, it is unlikely that this could entirely prevent this failure mechanism.

Compliance with the quenching technology ensures a high-quality product with the required properties. Violation of the modes of heating for quenching and cooling during quenching leads to the formation of defects such as soft spots and quenching cracks. The presence of soft spots in the metal is unacceptable due to structural stresses and the difference in mechanical properties between the base metal and the defective areas. To remove soft spots, repeated heat treatment is required. Quenching cracks occur due to internal stresses that exceed the resistance to destruction, due to non-simultaneous transformations and thermal expansion and compression. Products with quenching cracks are the final rejects.The article examines soft spots and thermal cracks on the outer surface of seamless pipes formed during heat treatment. The results of metallographic studies of the microstructure in the defect zone are presented, and the genetic and morphological features of defects are determined and studied. The structural heterogeneity was confirmed by Rockwell hardness measurements. Based on the data obtained, the causes of defects were determined.