(1. 华东船舶工业学院 材料及环境工程系，镇江 212003；
2. 东南大学 机械工程系， 南京 210006)
摘 要: 研究了Cu-Al-Be-B形状记忆合金的成分、 微观组织和相结构与阻尼和力学性能的关系， 通过扫描电镜原位观察合金在单向拉伸应力作用下裂纹萌生和扩展的特征。 结果表明： 应力诱发马氏体变体的转变使Cu-Al-Be-B合金具有较高的阻尼性能； 弹性各向异性和相变应变差引发晶界应力集中， 导致合金在拉伸条件下发生晶间断裂； 18R与2H马氏体混合程度大时， 会增加相变应变差引起的晶界应力集中和可能萌生的晶界裂纹源， 大大减小合金的塑性和强度。
关键字: Cu-Al-Be-B形状记忆合金； 马氏体变体； 阻尼性能； 力学性能； 原位拉伸
（1. Department of Material and Environment Engineering,
East China Ship Building Institute of Technology, Zhenjiang 212003, China;
2. Department of Mechanical Engineering, Southeast University,
Nanjing 210096, China）
Abstract:The relationships between composition, microstructure and properties such as damping and mechanics as well as in situ extension of Cu-Al-Be-B shape memory alloys were investigated by means of SEM . It is showed that the high damping capacity of alloys ascribes to the stress induced interface motion of martensite variants. It is clear that microcracks nucleate and develop along polycrystalline boundaries, in which stress concentration resulted from elastic anisotropy and difference of phase transformation strain exist. The more the mixture of 18R and 2H martensites, the more the stress concentration and the probable cracks around polycrystalline borders, therefore weakening mechanical properties, namely resulting in low plasticity and tensile strength.
Key words: Cu-Al-Be-B shape memory alloy; martensite variant; damping property; mechanical property; in situ tension
