EVALUATION OF MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AL-TAC COMPOSITES DEVELOPED BY MULTI-STEP STIR CASTING PROCESS

In the present study. four AA7075 composite samples reinforced with varying amounts of TaC in the range of 0.1wd%, 0.2wt%, 0.3wt%, 0.4wt%, were developed using a multi-step stir casting to improve the mechanical properties. The mechanical properties of the developed samples such as microhardness, tensile strength, compression strength, and elongation were characterized using a computerized Vickers hardness testing machine for microhardness and a Universal Testing Machine for both tensile and compression respectively. The effect of Tantalum carbide on the microstructures of the composite samples was characterized using an optical microscope. The microstructures and the mechanical properties of the developed composites were correlated. The results show a gradual increase in the mechanical properties with an increase in TaC reinforcement, However, the elongation decreased gradually with the increase in TaC content. The highest mechanical properties were found in the composite reinforced with 0.4. wt% TaC with the highest microhardness of 121 Hv, Ultimate Tensile Strength of 369 MPa, Yield Strength of 338 MPa and compression strength of 784 MPa.