Cu基形状记忆合金(SMAs)以其低廉的价格和良好的形状记忆效应而拥有广阔的应用前景，但单晶合金制备困难，而普通多晶合金易发生晶间断裂，严重降低了形状记忆性能和疲劳寿命，成为制约其广泛应用的瓶颈问题。我们采用定向凝固方法制备了具有高<001>取向织构和平直低能晶界特征的柱状晶（CG）组织Cu-Al-Mn SMAs，发现其同时具有与单晶相当的高超弹性和较高的强度。初步的机理分析显示，CG Cu-Al-Mn SMAs性能的提升除与高取向性有关外，低能晶界起到了重要作用。为此，本项目拟通过重点研究马氏体-晶界的交互作用机制，阐明晶界类型对Cu-Al-Mn SMAs性能的影响规律及机制；并进一步研究制备与加工过程中影响晶界类型的主要因素，探索高性能Cu基SMAs晶界类型的控制方法，为开发高性能Cu基SMAs及其高效制备加工方法提供参考。

Cu-based shape memory alloys (CSMAs) have broad application prospects because of their low cost and good shape memory effect. However, the CSMAs single crystal is hard to be prepared and the ordinary polycrystalline CSMAs often suffer from intergranular fracture, which severely reduces their shape memory effect and fatigue life, resulting in a bottleneck challenge for the application of CSMAs. We proposed a solution by means of texturing and grain boundary (GB) design, and prepared columnar-grained (CG) Cu-Al-Mn SMAs with high oriented texture and straight low-energy GB characteristics. Then, it is found that the CG Cu-Al-Mn SMAs have high superelasticity which is up to the level of single crystal, and relative high strength. The previous researches show that except the high oriented texture, the low-energy GB plays an important role in the properties improvement. In this project, the interaction between the martensite and GB will be focused on to clarify the effect of GB type on the properties of the Cu-Al-Mn SMAs. In addition, the key parameters to the control of the GB types of the high performance SMAs in the preparation and processing will be investigated. The results of this project will offer a significant reference to high efficient preparation and processing technology of high-performance CSMAs.