چكيده به لاتين
Abstract:
Constant improvement in engineering materials has effectively helped various industries to move forward. One of the important topics in mechanical and materials engineering is the improvement of surface properties of metals by using multiple methods of surface composite fabrication. For this purpose, various methods of modifying the surface properties such as electrophoretic deposition, plasma spray, ion implantation, laser melting, thermal oxidation, micro-arc oxidation are used. However, the high working temperature in these methods causes microstructural defects such as cold microcracks. , Cavities, large dendritic grains, and residual stresses. Meanwhile, friction stir processing is a surface composite fabrication method studied in various industrial and research institutes due to its simplicity, low energy consumption, environmentally friendly, controllable, structural, and mechanical properties. In this dissertation, the conversion of pure zinc metal surface to surface composite with hydroxyapatite reinforcement particles was performed using friction stir processing. Zinc has relatively weak mechanical properties that are not widely used in industry as the main part of mechanical parts. Still, this metal has excellent biocompatibility, biodegradability, and corrosion properties, and it is used as the main piece of essential parts in most medical industries. The excessive complexity of the mechanism and the severe plastic deformation of the friction stir process have attracted the attention of many researchers to simulate this process. Therefore, process simulations were performed to predict the results that are difficult to implement in practical experiments, such as temperature, stress, and effective strain in the process. The temperature monitoring system was used during the practical experiment with the obtained parameters to validate the simulation. Also, to compare the properties of raw zinc blocks with the properties of the composite, microstructural observation was used using an optical microscope, scanning electron microscope, and Field Emission Scanning Electron Microscope. The results showed a significant improvement in the structural properties of the composite sample. The hardness of the samples was compared using the micro Vickers hardness test, but no significant difference was observed between the pieces. Also, the corrosion properties of the samples showed a good improvement in the corrosion properties of the fabricated surface, which was compared using the polarization test.
Keywords: Friction Stir Processing; Metal Matrix Composites Manufacturing Methods; Metal Matrix Composites
