Cu-Zn-Al合金中转变的正电子湮没研究

INVESTIGATION OF THE TRANSITION IN Cu-Zn-Al ALLOY BY POSITRON ANNIHILATION TECHNIQUE

本文用正电子湮没Doppler展宽能谱和其它相关技术分析Cu-23 at％Zn-10 at％Al形状记忆合金不同温度淬火后的试样表明,该合金除了于700～600℃有α相变外,在550～500℃和300～250℃还有两个转变,前者可能是无序β相向有序B_2相的转变,后者可能是有序B_2相向有序DO_3相的转变。正电子湮没Doppler展宽能谱对。相变不敏感,但对有序转变敏感。

A shape memory alloy of Cu-23at% Zn-10 at% Al has been investigated by means of positron annihilation technique, differential thermal analysis and opitical microscopy. The experimental results indicate that there are three kinds of transition taking place during cooling from high temperature to room temperature: the first one is α-phase transformation which takes place in the temperature range of 700-600℃; the second one between 550℃ and 500℃ seems to be a transition of disordered β to ordered B2; and the third one between 300℃and 250 ℃seems to be a transition of ordered B2 to ordered DO3. Positron annihilation technique is sensitive to the latter two, but not to the former.