淬火保温时间对Cu-Zn-Al合金形状记忆效应的影响

Influence of Quenching Soaking Time on Shape Memory Effect of Cu-Zn-Al Alloys

研究了淬火保温时间对Cu Zn Al合金单向形状记忆效应 ηO 和双向形状记忆效应 ηT 的影响。研究结果表明 ,随训练次数的增加 ,位错增加 ,晶格原子有序度降低 ,单向形状记忆效应先急剧下降 ,然后缓慢下降 ,趋于稳定。但是 ,随训练次数的增加 ,双向形状记忆效应都先急剧上升 ,然后缓慢上升 ,趋于稳定。淬火保温时间过短或过长 ,都使形状记忆效应降低。淬火保温时间必须适当 ,即要使溶质原子充分均匀化 ,保证母相充分有序 ,又不使晶粒过大 ,才有较好的单向形状记忆效应 ηO 和双向形状记忆效应 ηT。最佳和最差保温效果时的单向形状记忆效应 ηO 和双向形状记忆效应 ηT 可分别相差达 70 %左右。

The influence of quenching soaking time on one-way shape memory effect η_O and two-way shape memory effect η_T of Cu-Zn-Al alloys were investigated.The quenching and ageing processes is that the alloys are soaked at 800℃ for 5～30min respectively and quenched in room temperature oil,then aged at 150℃ immediately for 30min,finally cooled by water in room temperature.The results show that the η_O rapidly decreases at first,then slowly decreases,finally trends to a certain stable value with the increasing of the training cycle numbers.But the η_T rapidly increases at first,then slowly increases and finally trends to a certain stable value with the increasing of the training cycle numbers.The shape memory effects are declined if the soaking time is too long or too short.The quenching soaking time should be suitable in order to make the solute atoms be homogeneousness and ensure the parent phase be order but the grains not be coarse,so an excellent shape memory effect could be gained through the heat treatment.The differences of η_O and η_T of the samples soaked under different time can reach 70% re-spectively after enough training.