Role of Si on machined surfaces of Al-based automotive alloys under varying machining parameters

A morphological change due to Si contend into Al-based automotive alloys has been conducted on the characterization of machined surfaces in terms of roughness, temperature, chips formation as well as microstructure evaluation under different machining conditions. For this experiment, a shaper machine with HSS single point V-shaped cutting tool is used at different cutting speeds and depths of cut. The experimental results show that the surface roughness of the alloys decreases with the cutting speed and depth of cut but it is more prominent in the case of the cutting speed. This is because of a high cutting speed, which is more associated with the higher temperature and softening the work material leading to better surface finish. Higher Si added alloys also exhibit a better surface finish because the sample content is different fine and hard intermetallic due to ageing treatment, which also makes the alloys more brittle. For brittle and higher hardness, it produces a higher temperature during machining. During machining, relatively curly and short chips are formed by the high Si added alloy because of its low elongation properties. The fracture surfaces of higher Si added alloy display more crack propagation obtained by plate-like Si rich intermetallic.