Cu-Al-Be形状记忆合金的应力腐蚀性能

STRESS CORROSION CRACKING CHARACTER OF Cu-Al-Be SHAPE MEMORY ALLOYS

用恒载荷法和慢应变速率法及SEM研究了Cu -Al-Be形状记忆合金在甘油、海水和氨介质中的应力腐蚀性能 .结果表明 ,Cu -Al-Be合金具有良好的抗海水应力腐蚀性能和较低的氨介质应力腐蚀倾向 .单相马氏体有较好的耐海水腐蚀能力 ,可减少腐蚀引起的裂纹源 ;外应力下马氏体的孪晶变形和变体间的界面迁移 ,则有利于松弛应力集中 ,阻碍和延缓腐蚀裂纹源的扩展 ,从而提高Cu

Comparing with ZHMn55-3-1 alloy,stress corrosion cracking experiments on Cu-Al-Be SMAs in media of glycerol,sea water and ammonia were carried out and the tensile fractures of experimental alloys were investigated by SEM.The result was clear that Cu-Al-Be SMAs show a high resistance to stress corrosion cracking,especially in sea water. Martensities have good ability against corrosion in sea water and the twin deformation and motion of the interfaces of the martensite variants is able to relieve stress concentration and delay the extending of corrosion cracks.Both of them exert a contribution to improving the SCC character of Cu-Al-Be alloys.