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The objective of this study is to create an ultra-thin palladium foil with a molecular dynamic (MD) simulation technique on a copper substrate surface. The layer formed onto the surface consists of a singular 3D palladium (Pd) nanoparticle structure which, by the cold gas dynamic spray (CGDS) technique, is especially incorporated into the low-cost copper substrate. Pd and Cu have been chosen for their possible hydrogen separation technology applications. The nanoparticles were deposited to the substrate surface with an initial velocity ranging from 500 to 1500 m/s. The particle radius was 1 to 4 nm and an angle of impact of 90° at room temperature of 300 K, in order to evaluate changes in the conduct of deformation caused by effects of size. The deformation mechanisms study revealed that the particle and substrate interface is subject to the interfacial jet formation and adiabatic softening resulting in a uniform layering. However, shear instabilities at high impact speeds were confirmed by the evolution of von Mises shear strain, temperature evolution and plastic strain. The results of this study can be used to further our existing knowledge in the complex spraying processes of cold gas dynamic spray technology.

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A study was conducted on the material characterization of aluminium (Al) and titanium carbide (TiC) metal-matrix composites produced via friction stir processing. Different process parameters were employed for the welding process. Rotational speeds of 1600 min -1 to 2000 min -1 , at an interval of 200 min -1 and traverse speeds of 100 mm/min to 300 mm/min, at an interval of 100 mm/min were employed for the welding conducted on an Intelligent Stir Welding for Industry and Research (I-STIR) Process Development System (PDS) platform. The characterizations carried out include light microscopy and the scanning electron microscopy analyses combined with Energy-Dispersive Spectroscopy (SEM/EDS) techniques to investigate the particle distribution, microstructural evolution and the chemical analysis of the welded samples. Vickers microhardness tests were used to determine the hardness distribution of the welded zone and tensile testing was conducted to quantify the strength of the welded area compared to the base metal in order to establish the optimal process parameters. Based on the results obtained from the characterization analysis, it was found that the process parameters played a major role in the microstructural evolution. A homogenous distribution of the TiC particles was observed at a high rotational speed of 2000 min -1 and a low traverse speed of 100 mm/min. The highest hardness value was measured at the stir zone of the weld due to the presence of the TiC reinforcement particles. The tensile strength also increased as the rotational speed increased and 92 % joint efficiency was recorded in a sample produced at 2000 min -1 and 100 mm/min. The EDS analysis revealed that Al, Ti and C made up the composition formed in the stir zone. The optimum process parameter setting was found to be at 2000 min -1 and 100 mm/min and can be recommended. Keywords: aluminium, friction stir welding, mechanical properties, metal matrix composite, microstructural evolution, titanium carbide V tem raziskovalnem delu je bila izvedena obse`na {tudija karakterizacije kovinskega kompozita aluminija (Al ) in titanovega karbida (TiC) izdelanega z me{alno tornim varjenjem. Za postopek varjenja so bili uporabljeni razli~ni procesni parametri. Rotacijski hitrosti 1600 min -1 do 2000 min -1 , v razmaku po 200 min -1 , in pre~nih hitrostih od 100 mm/min do 300 mm/min, v intervalu 100 mm/min, je bilo uporabljeno za varjenje na industrijski platformi za razvoj in raziskave (PDS) sistema inteligentnega varjenja z me{anjem (I-Stir). Izvedena karakterizacija vklju~uje svetlobno mikroskopijo in vrsti~no elektronsko mikroskopijo v kombinaciji z energijo disperzijsko spektroskopijo (SEM/EDS), za preiskavo porazdelitve delcev, razvoja mikrostrukture in kemijsko analizo zvarjenih vzorcev. Za dolo~itev optimalnih procesnih parametrov je bil uporabljen Vickers preizkus mikrotrdote, s katerim je bila dolo~ena porazdelitev trdote na podro~ju zvara, z nateznim preizkusom pa je bila dolo~ena trdnost zvara v primerjavi z osnovnim materialom. Na osnovi rezultato...

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