The studies on micro-structural defects in deformed composite matrix of Al-Si-Mg and SiC

Detailed Fourier line shape analysis has been performed on three different compositions of the composite matrix of Al-Si-Mg and SiC. The alloy composi tion in wt% is Al-7%Si, 0.35%Mg, 0.14%Fe and traces of copper and titanium (similar to 0.01%) with SiC varying from 0 to 30wt% in three steps i.e., 0, 10 and 30wt%. The line shift analysis has been performed by considering 11 1, 200, 220, 311 and 222 reflections after estimating their relative shift. Peak asymmetry analysis has been performed considering neighbouring 111 an d 200 reflections and Fourier line shape analysis has been performed after considering the multiple orders 111 and 222, 200 and 400 reflections. Combi ning all these three analyses it has been found that the deformation stacki ng faults both intrinsic alpha' and extrinsic alpha " are absent in this al loy system whereas the deformation twin beta has been found to be positive and increases with the increase of SiC concentration. So, like other Al-bas e alloys this ternary alloy also shows high stacking fault energy, and the addition of SiC introduces deformation twin which increases with its concen tration in the deformed lattices.