Influence of TiC addition on the surface roughness during turning of AA 7075 alloy processed through stir-casting

Abstract

This research work had focused on manufacturing AA 7075/(0, 2.5, 5 and 7.5 wt%) TiC metal matrix composites through stir casting route. The manufactured composites had effectively characterized using the optical microscope. It had observed from the optical microstructures that the uniform distribution of TiC ceramic particles and its embedding over the ductile AA 7075 matrix had successfully obtained which exhibited excellent mechanical (218 HRC for 7.5 wt% TiC composite) and machining behavior with the function of TiC particles when compared to monolithic AA 7075 alloy. There had a grain refinement in the composites due to TiC particles addition. The machinability of experiments had conducted by varying the cutting speed, the feed rate, the depth of cut and the tool nose radius. The surface roughness had measured and the results had indicated that AA 7075–7.5 wt% TiC ex-situ composites had exhibited a lower value of surface roughness which had expected to high-strength in the matrix that produced immediate shearing action when compared to other samples. Further, the tool nose radius had played a major role in the surface roughness in which higher value of tool nose radius (0.8 mm) sample had shown improved surface finish.

Keywords

• AA 7075 Al alloy
• TiC
• metal matrix composite
• characterization
• mechanical properties
• turning