Abstract
The effect of aging on abrasion rate of an Al-5.0wt.%Zn-2.3wt.%Mg7.5wt.% SiC composite was investigated and compared with that for Al-5.0wt.% Zn-2.3wt.% Mg alloy aging at temperatures of 120, 160 and 200 °C. The results show that aging hardness explicitly determines the abrasion rate of the Al-Zn-Mg alloy by an inverse linear relationship for all treatments. However, in the Al-Zn-Mg-SiC composite, aging temperature and duration are dominant factors for abrasion rate. Higher temperature or longer aging would yield better abrasion resistance. In particular, overaging would result in the best resistance. Electron probe microanalysis on the abraded surface indicated that higher abrasion resistance of the composite is attributable to the stronger interface bonding between SiC particles and the matrix. The anchoring mechanism based on interface precipitation on the surface of SiC particles and the contraction mechanism based on the dimensional contraction of the matrix explain the variation in interface-bonding strength and thus the abrasion resistance. © 1988.