SUBSTITUTIONAL SOLUTES IN ALRU .2. HARDENING AND CORRELATIONS WITH DEFECT STRUCTURE

Solid solution hardening effects are reported for Al-Ru-based binary and ternary alloys as a function of off-stoichiometry and of the substitution of the solutes Co and Fe for Ru, and of Ti for Al. Microhardness and thermally stepped flow stress are reported as a function of temperature. Off-stoichiometry and ternary additions both produce hardening except for brittle compositions. In binary alloys the strength of the hardening is consistent with elastic effects of conventional substitutional solute. Ternary alloys are more complicated. Two possibilities are that point defects have paired to produce strong hardening or that superimposed effects have produced partial cancellation of modulus and lattice parameter effects of multiple separate point defects.