中文摘要：

形状记忆合金(SMA ) 的机械行为是仔细与它的微观结构的形成和进化有关。通过理论分析和试验性的观察，导致压力的 martensitic 转变在单轴的紧张状况下面单个水晶处理基于 Cu 的 SMA，这被发现由三个时期组成了：成核，混合成核和生长，并且由于生长合并。在成核期间，压力很快落下，当阶段部分慢慢地增加了时，接口的数字很快增加了。在第二个时期，压力和接口数字稍微变化了，但是阶段部分戏剧性地增加了。最后，当接口的数字快速减少了时，压力和阶段部分慢慢地变化了。而且，转变能具有，这被发现多级式：在几紧张并且相应地的锋利的压力落下，成核和生长过程在样品的几部分伪独立地发生了。

英文摘要：

The mechanical behavior of shape memory alloys （SMAs） is closely related to the formation and evolution of its microstructures. Through theoretical analysis and experimental observations, it was found that the stress-induced martensitic transformation process of single crystal Cu-based SMA under uniaxial tension condition consisted of three periods： nucleation, mixed nucleation and growth, and merging due to growth. During the nucleation, the stress dropped rapidly and the number of interfaces increased very fast while the phase fraction increased slowly. In the second period, both the stress and the interface number changed slightly but the phase fraction increased dramatically. Finally, the stress and the phase fraction changed slowly while the number of interfaces decreased quickly. Moreover, it was found that the transformation could be of multi-stage： sharp stress drops at several strains and correspondingly, the nucleation and growth process occurred quasi-independently in several parts of the sample.