【摘要】 用SEM原位拉伸实验对TiNi形状记忆合金试样的断裂过程进行了研究和分析.结果表明,TiNi形状记忆合金的断裂与钢的脆性解理断裂不同.TiNi形状记忆合金的断裂受解理机制和孔洞在第二相颗粒处的形核、长大、连接机制控制.这两种材料失效机制共同作用,其中哪一种占统治地位取决于诸多因素.应力诱发马氏体相变对TiNi形状记忆合金的断裂具有重要的影响.更多还原

【Abstract】 Fracture mechanism of titanium-nickel shape memory alloys specimens are observed and analyzed carefully in situ SEM tensile experiment.Investigation results indicate that fracture of TiNi shape memory alloys is different from brittle cleavage fracture of steels.The former is controlled by cleavage mechanism coupled with void nucleation, growth, and coalescence at the position of second phase particles.The tow mechanisms of material failure act in conjunction with one another and the dominance of one over the other depends on many factors.The reversible stress induced martensitic transformation has a very important effect on the fracture of TiNi shape memory alloys.更多还原