Fabrication and mechanical properties of AA5083/TiB2 in situ Composite by stir casting process

The Purpose of this study is fabrication aluminum matrix composites reinforced with TiB2 in situ ceramic particles by the stir casting process. So, produce composites with 2%, 4% and 6 wt% and contrast with AA5083 alloy of reinforcing particles without. In this study, in order to impurities and surface contamination cleanse and also water molecules contained in the powders of TiO2 and B2O3, preheating operation performed on them. Then milling operation done with speed 750 Rpm for 15 hours, in order to mechanical activation and prevent performed of adverse reactions between the powders in during the casting process. After preparing the powders, they are stoichiometric determined ratio to achieve values of 2%, 4% and 6wt% TiB2 phase were added to the AA5083 alloy molten and after stirring for 15 minutes with speed 350 Rpm, the casting was performed. At the end of in order to properties improve of casting specimens from used hot extrusion process. Then, using phase analysis (XRD), microstructure analysis (OM and SEM) and tensile, hardness and density tests, production or non-production, distribution of reinforcing particles and mechanical properties investigated of samples. The ultimate goal of this research is, using a combined method to problems solve of cast aluminum matrix composites and improving their properties. The results showed an improvement in mechanical properties of samples with increasing reinforcing particles up to 4wt% after completion treatment. As the highest tensile strength and hardness obtained at cast and extruded sample (at temperature of 330 ° C) AA5083/4% TiB2.