Localized Plastic Deformation and Microstructure Properties of Al/Si Alloy Improved with Al3Ni Compound

Abstract

The microstructure of AS10/xNi hypoeutectic alloys with (x = 0.01% and 0.05%) was investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Localized permanent plastic deformation (Vickers hardness (HV)) was conducted on the samples before and after sintering. After sintering, the results showed a significant improvement in hardness with the addition of Ni atoms. From the XRD map, it was found that there was a shift in the peak positions as the Ni atoms were added. This shift is a result of the incoincidence of d_hkl levels in the Al-phase before and after the addition of Ni. This mismatch in d_hkl levels is associated with the lattice defects and lattice parameters. From the SEM images, the silicon powder particles in the binary composition are large and elongated plates, whereas those in the ternary composition are small and semi-spherical particles. This reduction in the particle size of the modified alloy is attributed to the presence of Ni atoms in the alloys.