(1. 華東船舶工業(yè)學(xué)院 材料及環(huán)境工程系，鎮(zhèn)江 212003；
2. 東南大學(xué) 機(jī)械工程系， 南京 210006)
摘 要: 研究了Cu-Al-Be-B形狀記憶合金的成分、 微觀組織和相結(jié)構(gòu)與阻尼和力學(xué)性能的關(guān)系， 通過掃描電鏡原位觀察合金在單向拉伸應(yīng)力作用下裂紋萌生和擴(kuò)展的特征。 結(jié)果表明： 應(yīng)力誘發(fā)馬氏體變體的轉(zhuǎn)變使Cu-Al-Be-B合金具有較高的阻尼性能； 彈性各向異性和相變應(yīng)變差引發(fā)晶界應(yīng)力集中， 導(dǎo)致合金在拉伸條件下發(fā)生晶間斷裂； 18R與2H馬氏體混合程度大時(shí)， 會(huì)增加相變應(yīng)變差引起的晶界應(yīng)力集中和可能萌生的晶界裂紋源， 大大減小合金的塑性和強(qiáng)度。
關(guān)鍵字: Cu-Al-Be-B形狀記憶合金； 馬氏體變體； 阻尼性能； 力學(xué)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
