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Abstract The primary objective of this study is to investigate the microstructural, mechanical, and wear behaviour of AZ31/TiC surface composites fabricated through friction stir processing (FSP). TiC particles are reinforced onto the surface of AZ31 magnesium alloy to enhance its mechanical properties for demanding industrial applications. The FSP technique is employed to achieve a uniform dispersion of TiC particles and grain refinement in the surface composite. Microstructural characterization, mechanical testing (hardness and tensile strength), and wear behaviour evaluation under different operating conditions are performed. Response surface methodology (RSM) is utilized to optimize the wear rate by considering the effects of process parameters. The results reveal a significant improvement in hardness (41.3%) and tensile strength (39.1%) of the FSP-TiC composite compared to the base alloy, attributed to the refined grain structure (6–10 μm) and uniform distribution of TiC particles. The proposed regression model accurately predicts the wear rate, with a confirmation test validating an error percentage within ± 4%. Worn surface analysis elucidates the wear mechanisms, such as shallow grooves, delamination, and oxide layer formation, influenced by the applied load, sliding distance, and sliding velocity. The enhanced mechanical properties and wear resistance are attributed to the synergistic effects of grain refinement, particle-accelerated nucleation, the barrier effect of TiC particles, and improved interfacial bonding achieved through FSP. The optimized FSP-TiC composites exhibit potential for applications in industries demanding high strength, hardness, and wear resistance.

A356 Aluminium Alloy-Zircon composites were synthesized through the stir casting technique by introducing different volume fractions of zircon particles (3, 6, and 9 %). Stir casting process was carried out at the stirring speed of 600 rpm and stirring time of 10 minutes. The microstructure of the composites showed an even distribution of zircon particles. The composites' hardness improved with an increase in vol.% of zircon constituent part. Wear loss against different sliding distances and load was investigated through a Pin-on-Disc wear testing apparatus with an L16 orthogonal array. Taguchi's parameter optimization demonstrated that material loss was influenced to a significant extent by adding Zircon. Wear resistance of the synthesized composite was investigated and verified using Analysis of Variance (ANOVA). Zircon content (39.33%) was found to be the most influencing factor on wear loss, followed by the applied load (36.80%) and sliding distance (21.54%). Zircon improves the properties of the composite through restricting the growth of dendritic arms in A356 alloy. In addition, reinforcement particles enhanced the strengthening of the composites through Orowan mechanism by inhibiting the movement of dislocations. ANOVA technique was successfully used to examine the effect of individual parameters on wear loss of A356 alloy-Zircon composites MMCs.

In the present investigation Ni particles were added in varying weight fractions (0.5, 1.0 and 1.5%) to AA6061 alloy during stir casting. To prepare Al-Ni intermetallic reinforced Aluminium Metal Matrix Composites (Al MMCs), as-cast samples were subjected to T6 treatment (Solutionization at 550°C followed by ageing at 2,4,6,8 and 10 hours). Base alloy was also subjected to T6 treatment for comparison purpose. Hardness of the samples were obtained using Vickers hardness test. Samples in the peak aged (T6) condition were subjected to metallographic examination. Influence of Ni particles on the hardness and grain refinement was investigated. X-ray Diffraction analysis of the Ni added samples revealed the presence of Al-Ni intermetallic phase formation in the peak aged (T6) Condition. Scanning Electron Microscope – Energy Dispersive X-Ray Spectroscopy analysis of composites in the peak aged (T6) condition were carried out to study the formation of the Al-Ni intermetallic phase. Effect of Al-Ni intermetallic phase on wear and friction behavior of the composite samples were studied and compared with that of the base alloy in the peak aged (T6) condition.

Friction Stir Process (FSP) was employed to develop Cupro-Nickel/Zirconium Carbide (Cu-Ni/ZrC) surface composites. Five different groove widths ranging from 0 to 1.4 mm were made in CuNi alloy plate to incorporate different ZrC volume fraction (0, 6, 12, 18 and 24 %) to study its influence on the structure and properties of Cu-Ni/ZrC composite. Processing was performed at a Tool Rotational Speed (TRS) of 1300 rpm, Tool Traverse Speed (TTS) of 40 mm/min with a constant axial load of 6 KN. The study is performed to analyse the influence of ZrC particles and the volume fraction of ZrC particles on the microstructural evolution, microhardness, mechanical properties, and tribological characteristics of the Cu-Ni/ZrC composite. The fracture and worn-out surfaces are analysed using Field Emission Scanning Electron Microscope (FESEM) to identify the fracture and wear mechanisms. The results demonstrated a simultaneous increase in microhardness and tensile strength of the developed composite because of grain refinement, uniform dispersion, and excellent bonding of ZrC with the matrix. Besides, the wear resistance increases with increase in volume fraction of ZrC particles in the composite. The surface morphology analysis revealed that the wear mechanism transits from severe wear regime to mild wear regime with increase in volume fraction of ZrC particles.

In this paper, aluminium alloy of grade ADC-12 was considered as a base metal and chromium carbide (Cr3C2) particles were reinforced through friction stir process. A detailed analysis of mechanical property and metallurgical characterization studies were performed to evaluate the surface composite. Remarkable changes were observed in the developed composite due to the mechanical force produced by the stir tool with an increase in hardness. The metallurgical investigation infers that the presence of silica in ADC-12 alloys has undergone mechanical fracture and long needle structure changed to reduced size. On the other hand, at higher tool rotational speed, the uniform distribution of hard particles was confirmed through SEM micrographs. Thus the modified surface composite has produced good mechanical property with high metallurgical qualities.

One of the different and pioneering solid-state techniques, friction stir processing (FSP), is employed for the production of surface composites. In this research, the matrix selected was copper-nickel (CuNi) with hard boron carbide particle as reinforcement. The objective of the current research work is to produce reinforced 90/10 copper-nickel surface composites reinforced with B4C fabricated via FSP. The influence of tool rotational speed on macrostructure, microstructure, grain size analysis, microhardness, and wear studies of friction stir processed (FSPed) CuNi/B4C surface composites was assessed. For high rotational speed (1400 rpm) of stir tool, the modified surface area found is a maximum of 44.4 mm2 with uniform dispersion of hard particle reinforcement. The presence of hard particle in the surface area is revealed through the electron imaging and the spectroscopic results. Spectra mapping shows the uniform distribution of hard particle over the FSPed area, and the evidence is obtained with XRD analysis. From the experimentation, it is interesting to report that the reinforcements have decreased the surface hardness for an increased rotational speed of stir tool. The hardness recorded for minimum rotational speed is 223 HV which has gradually decreased to 178 HV for 1300 rpm. It has directly influenced the wear rate of modified FSPed, as hardness is directly proportional to wear behavior. The worn surface and fractured morphology of the CuNi/B4C surface composites were also studied using Field Emission Scanning Electron Microscope (FESEM).

The growing demand for sustainable materials is driving the adoption of microcrystalline cellulose (MCC) from renewable plant sources. This study investigated the isolation of MCC from Rosa indica petal (RIP) waste via acid hydrolysis. RIP was pretreated with alkali extraction and bleaching prior to acid hydrolysis. Chemical analysis revealed the composition of pretreated RIP was 79.56 wt.% cellulose, 9.87 wt.% hemicelluloses, and 5.69 wt.% lignin. Fourier‐transform infrared spectroscopy (FTIR) showed reduced peaks at 3332.88, 2851.95, and 1577.75 cm−1 after alkali treatment, indicating removal of hemicelluloses and lignin. X‐ray diffraction (XRD) found the crystallinity index of the isolated Rose indica petals cellulose (RIPC) MCC was 72.31%, suggesting effective purification. Thermogravimetric analysis (TGA) revealed RIPC MCC had a decomposition temperature of 296.65°C, superior to raw RIP at 211.25°C. In addition, atomic force microscopy (AFM) and scanning electron microscopy (SEM) showed RIPC MCC had fibrous morphology with fiber diameters ranging from 16.2–22.4 nm. In summary, RIPC MCC with high purity, crystallinity and thermal stability was successfully isolated from RIP waste via acid hydrolysis. The high performance of RIPC MCC demonstrates the potential of RIP leftovers as a renewable source for MCC production. RIPC MCC could serve as a promising reinforcement filler in nanocomposites due to its advantageous properties. [ABSTRACT FROM AUTHOR]