Abstract
The effects of Cr and Ti on cooling and tempering eutectoid transformation and on the self-annealing of Cu-Al binary alloy were measured by means of differential dilatation, differential thermal analysis and microscopic observation. The results obtained were as follows: (1) The β→α+γ2 transformation temperature of Cu-11.6Al-1.5Cr was higher than that of Cu-Al binary alloy and that of Cu-12.1Al-1.6Ti was lower. (2) The processes of cooling and tempering transformations of Cu-11.6Al-1.5Cr and Cu-12.1Al-1.6Ti alloys were the same as those of Cu-Al binary alloy, but the microstructures of Cu-12.6Al-1.2Cr and Cu-12.7Al-1.4Ti alloys water-quenched from 800°C were β′+γ′ by phase separation and the Al concentrations in these alloys were lower than in the Cu3Al type lattice of these alloys. (3) The self-annealing of Cu-Al binary alloy was enhanced by adding Cr and Ti.
