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为了明确热HCP马氏体对CoAl和CoNi合金形状记忆效应的作用,研究CoAl和CoNi合金形状记忆效应(SME)与应力诱发马氏体和热HCP马氏体之间的关系。采用原位金相观察合金深冷前后热诱发马氏体的变化,并研究其对应力诱发马氏体和形状记忆效应的影响。结果表明,CoAl和CoNi合金的形状记忆效应都来源于应力诱发HCP马氏体,热马氏体对两者形状记忆效应的贡献都是强化基体。CoAl合金形状记忆效应高于CoNi合金的原因是Al原子对基体更强的固溶强化作用导致CoAl合金基体强度高于CoNi合金强度。
In order to clarify the effect of hot HCP martensite on the shape memory effect of CoAl and CoNi alloys, the relationship between SME and stress-induced martensite and hot HCP martensite was investigated. The changes of heat-induced martensite before and after cryogenic treatment were observed by in-situ metallography, and the effect of stress-induced martensite and shape memory effect was also investigated. The results show that the shape memory effect of CoAl and CoNi alloys are all derived from stress-induced HCP martensite. The contribution of hot martensite to the shape memory effect of both is a strengthening matrix. The reason why the shape memory effect of CoAl alloy is higher than that of CoNi alloy is that the stronger solid solution strengthening effect of Al atoms on the matrix results in that the matrix strength of the CoAl alloy is higher than that of the CoNi alloy.