拘束加熱が銅-亜鉛-アルミニウム合金の自発的形状変化に与える影響

Abstract

A Cu-Zn-Al alloy showing spontaneous shape changes at high temperatures was aged as the pre-deformed state, and the effects of the heat treatment, i.e., constrained aging, on the reversible shape memory effect, the inverse shape memory effect and the high temperature shape change, have been investigated as a function of deformation temperature, aging temperature and aging time.The results are summarized as follows; (1) When the aging temperature is lower than Af, both the amounts of the inverse shape memory effect and the high temperature shape change become nearly 0. (2) When the temperature is higher than Af, both of them increase with increasing temperature, and they show maximum values in the temperature range higher than 420 K. However, the amount of the inverse shape memory effect decrease with bainite transformation. (3) Under the conditions where a specimen shows the reversible shape memory effect, it shows the inverse shape memory effect and the high temperature shape change. (4) There is a good correlation between the amounts of the inverse shape memory effect and the high temperature shape change.