Correlation between matrix residual stress and composite yield strength in PM 6061Al-15Â vol% SiCw

Upon relieving residual stress (RS) by means of isothermal annealing, it is observed that the RS and the yield strength (YS) of a 6061Al alloy follow a linear relationship. In contrast, two regimes are observed for a SiC-reinforced composite: firstly the YS decreases at constant RS, then the RS relaxes at constant YS.