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A new cast iron material with a higher Cr content than usual is analyzed by chemical, micro-structural and friction coefficient point of view. The material was obtained by classical melting and the results compared with the experimental results obtained from a standard cast-iron used for applicative disk brake. Four different mechanical solicitation rates were used on the same material surface and the same load. The solicitation regime can be considered as semi-liquid and similar to a raining day experimental conditions. In this paper no thermal considerations were present or discussed. The results present a bigger friction coefficient of the new material and further considerations are necessary for example in a different friction regime.

The present investigation has been conducted in order to study the fatigue and corrosion fatigue behaviour of an aluminium alloy (99,5%Al) substrate coated with a 106 MXC deposited by thermal spraying in electric arc. It has been determined that the deposition of such a coating on the aluminum substrate gives rise to significant gains in fatigue life in comparison with the uncoated substrate, when testing is carried out both in air and in a 3,5 wt.% NaCl solution. It has been shown that during testing in air, the fatigue gain ranges between ~131 and 186%, depending on the maximum alternating stress applied to the material. Larger fatigue gains are associated with low alternating stresses. Also, when fatigue testing is conducted in the NaCl solution, the gain in fatigue resistance varies between ~124 and 159%. Fatigue cracks have been observed to initiate at the coating surface and then grow towards the substrate after propagating through the entire coating thickness. Although in the present work residual stresses were not measured, it is believed that the gain in fatigue life of the coating–substrate system is due to the presence of compressive residual stresses within the coating which hinder fatigue crack propagation. The deposition of the coating does not give rise to significant changes in the static mechanical properties and hardness of the aluminum alloy substrate.

By plastic deformation processing techniques is possible to achieve parts with complex geometric configuration and superior mechanical characteristics required in many industries such as aerospace, energy, transport etc. These parts are subjected to high loads or involves a special safety in operation and therefore can not be achieved by empirical design techniques. In addition, industrial development requires obtaining parts with smaller dimensional deviations without defects from expensive materials which are manufacturing in smaller series. To cope with these trends in the currently processed by severe plastic deformation is necessary to apply plastic deformation simulation using finite element method. Aluminum flow simulation is necessary for plastic deformation predetermination the total force, which is used to choose the machine deformation. Also through flow simulation aims to determine contact stress material - deformation tools, necessary stress dimensioning tool, in this case the active plate, punch and counterpunch.

In this paper it has been deposited films of titanium oxide (TiO2), on a support of glass, by a D.C. magnetron sputtering system, by varying the working pressure (p = 2∙10-3 - 6.5∙10-3mbar) of the substrate temperature on three levels. The obtained layers were investigated and characterized by optical microscopy, Scanning Electron Microscopy SEM, X-ray diffraction and Atomic Force Microscopy. It was observed that, by modifying technological parameters of the process (working pressure and substrate temperature) it is changing the initial orientation of the compounds ((100) turns into (101) or (002)). The AFM analysis has allowed the observation of the fact that the average roughness of deposited films, expressed as RMS, has increased over 98% at the increasing of sputtering pressure from 2 10-3mbar to 6.5 10-3mbar. SEM analysis showed that the density of the deposit increases with substrate temperature. The granulation of the films obtained, presents an increasing trend with the variation of process parameters.

A new cast-iron material was obtained by melting in an induction furnace. The material was microstructural and chemical characterized before and after a wear test. We analyze the chemical composition of the material at macro-scale using a Spark Spectrometer and at micro-scale using Dispersive Energy Spectrometer. Microstructure before and after the external solicitations was observed using a Scanning Electron Microscope. We also evaluate the influence of external force on the dendrites microstructural and chemical modification.

The paper aims to determine, through experiments, the necessary force for detaching the deposited layer (SD) from the support layer (SB). The thermal sprayed coating was formed by successive deposition of two sub-layers, one for anchorage and the second for corrosion resistance. Shear adhesion strength tests were performed on a specialized stand, while force (Fad) and displacement (x) values were recorded with a data acquisition system. The variation curves, Fad = f (x), outline the evolution of the detachment process of the sprayed layer and the two main components of the deformation process: slip and breakage.

This paper presents a comparative study on the corrosion behaviour of the Al depositions, obtained by thermal spraying in electric arc - the classic method (ASP) and the Al deposits behaviour, carried out with a thermal spray combined device (CTSD). The use of CTSD allows the thermal field modification of the spraying jet and implicitly the modifying the mechanical, physical and chemical properties of the deposits of aluminium. Evaluation of the corrosion behaviour of the aluminium deposits was achieved by exposure to salt water - sea water (3.5NaCl). The corrosion products, formed on the surface of the coatings, were investigated based on the photographic records, electronic microscopy – SEM and X-ray diffraction. The aluminium oxide, obtained on the depositions, carried out by using CTSD - exposed in saline environment is more adherent then the oxide obtained on the deposits, carried out through ASP - which leads to a loss in thickness.

This paper presents materialization through a device of severe plastic deformation process by multiaxial forging. In essence, by design, the device includes a board reinforced with fretting rings where the severe plastic deformation takes place and an assembly, punch-counterpunch that transmits the force from the source and performs multiaxial forging as a discontinuous process. The device has a high level of universality and has the following advantages: contains an extraction system of deformed blank from the active fretted broad; ensures workpiece centering into place of active plate, contains a system for measuring the strength of forging; can be used on any type of press.

This Paper Aims to Determine by Experiment Total Force and Stress of Deformation Depending on Punch Stroke and the Level of Deformation on Severe Plastic Deformation of Aluminum by Multiaxial Cold Forging. the Deformation Force in Multiaxial Forging Depends on a Number of Parameters of whom the most Important are: Strain, the Flow Force of Aluminum, Deformation Speed, the Friction between the Material and the Die, Shape and Size of Die, the Dimensions of Deform Profile, Shape and Dimensions of Workpiece, Temperature Variation during the Process, Physical and Mechanical Properties of the Workpiece Material, the Structural Inhomogeneity of Workpiece Material. the Deformation Process is Discontinuous and Includes Deformation Processes that Define a Cycle of Severe Plastic Deformation. this Paper Aims to Determine the Force and Stress Corresponding to the First 12 Cycles of Severe Plastic Deformation.

The paper presents the determination of the yield stress for copper, Cu_99.75, at standard ambient temperature, by means of upsetting of cilyndrical specimens, taking account the allowable degree of deformation of this material. The outcomes achieved can be used both plastic deformation processes and volumic deformation simulation of copper Cu_99.75.

Aluminum silicon alloys, the 4xxx group of the aluminum alloys, are mostly processed into cast parts. As for other cast designated alloys, their weldability is often considered as an unimportant feature. The interest, if any, is almost completely related to the repair welding.The present work analyses how silicon particle dimensions, which depends mostly on the silicon content into the metallic matrix, affects the weld properties. Also it is revealed the HAZ metallographic aspect for two frequently welding processes used on aluminum alloys, TIG and FSW. Friction welds resistance is better than that of the TIG welds, associated with a lack of symmetry (retreating side versus advancing side).Silicon particles diminish their dimensions for hypo eutectic or eutectic concentrations; for hyper eutectic compositions the effect has an almost unimportant effect.

The main objective of this paper is to evaluate the mechanical properties, chemical and corrosion resistance of four types of metallic coatings: FeCr, FeCoCr, and FeCoCrNi, FeCrNi sprayed through thermal spraying in electric arc on an anchor substrate type 95Ni5Al or 78.3Ni20Cr1. 4Si0.3Fe. The five layers tested were deposited on carbon steel support low alloyed and the obtained results have provided a picture regarding the possibilities of using of the deposits. Because these types of alloys are used to increase the wear resistance of tools, it is very important to know their behaviour is saline environment, because the contributions brought by this paper would increase the applicability domain of these materials (could be used to recondition by thermal spraying the tools used in naval and petroleum industry). The researches of the obtained deposits have been carried out through several methods to screen their performance. Therefore, there have been done investigations on the microstructural morphology of the deposit, by optical microscopy (OM) and scanning electron microscopy (SEM). The OM and SEM results have sought to determine the degree of uniformity of the deposits and the amount of pores and oxides in layer. The physical properties of coatings were also evaluated by adhesion and porosity quantification. The corrosion resistance was evaluated by exposing samples in saline fog chamber. The corrosion products formed on the surface layers were investigated by scanning electron microscopy (SEM) analysis of the SEM. The intermediate alloy 78.3Ni20Cr1.4Si0.3Fe used as anchoring layer allowed the reducing of the pores and micro cracks frequently found in the ordinary 95Ni5Al alloy. It has been observed that the deposits based on NiCrCo are good enough to be used as an efficient coating of carbon steel in aggressive marine environments.

Steel depositsobtained by thermal spray arc have physical-chemical and mechanical properties dependent on operational parameters of the spraying process. Thus, the electric current intensity, the spray distance, the velocity, respectively the driving gas pressure are the parameters that influence the mechanical properties of the steel deposits obtained by thermal spraying. The interaction between particles- gas drive seen in the classic arc spray has the effect the lowering of particles temperature and implicitly of the physical and mechanical properties of the deposit. Using a new device, combined, in which over the thermal field, created by the electric arc, would overlap a second thermal field, created by a gaseous fuel burning, would determine the maintaining of high temperature of the particles and implicitly changes of the physical, chemical and mechanical properties of the deposit. Such a combined spraying device would be called device for spraying in electric arc-thermally activated. The paper aims to present a comparative study of the physic chemical and mechanical properties of steel deposits obtained with two spraying processes: the classical process and the combined spraying process - in electric arc thermally activated.Investigations carried out on the structure of deposits by electron microscopy SEM, XRD analysis and image analysis performed at zone level Layer-Substrate as well the deposits adherence assessment in accordance with EN 582-allows the highlighting properties, the arguing of differences between the properties of the deposits made by the two methods as well as the establishing advantages and disadvantages using those processes.

The physic-chemical and mechanical properties of steel deposits obtained by thermal spraying depend on technological parameters of the spraying process. Generally, wear resistance of the deposits depends on the degree of porosity and the adhesion of the layer to the substrate. In the case of the deposits obtained by spraying, studies have shown that between deposited layer (SD) and substrate (S) there are the following types of adhesions: mechanical, metallurgical, superficial, physical and diffusive. Each type of adherence, enumerated above, works through a well-defined mechanism so that it can be said that the adhesion of the obtained deposits by thermal spray is a sum of mechanisms which interacting. How these mechanisms interact, as well the percentage of the influence is determined by: operating parameters, by the deposit material and thermal treatments after the deposit obtaining. This paper proposes to determine the influence of thermal treatment on adherence of 60T deposits obtained by thermal spraying in electric arc- as a thermal processing method after metallization. The assessment of adherence deposit 60T - in two ways, according to with EN 582 and DIN 27201/2005 in conjunction with the investigations of electron microscopy (SEM), XRD analysis, and image analysis performed at both the zone: Coating - Interface - Substrate (CIS) has revealed the presence of diffusion and the structural constituents. The graphs of adherence variation for 60T deposits with the concentration gradient of the alloying elements of the 60T layer respectively of adherence layer (75B) obtained experimentally by investigations carried out on the substrate have demonstrated the role of the secondary thermal treatment on the deposit adherence.

The transient target current is used to characterize the aluminum laser produced plasma for various fluences and target external polarizations. A double peak structure of the electronic part was experimentally observed, as consequence of the existence of non-Maxwellian electron distribution through the hot and cold electrons. Applying an external voltage on the target, the ionic part becomes oscillatory, with plasma ion frequency. Assuming that particle motions take place on continuous and non-differentiable curves, a fractal hydrodynamic model of plasma expansion is built. In such conjecture, the analytical solutions and numerical simulations allow a reasonable interpretation of our experimental results.