沉淀强化型超级铁基形状记忆合金马氏体相变热滞的调控机制研究

项目名称： 沉淀强化型超级铁基形状记忆合金马氏体相变热滞的调控机制研究

项目编号： No.51201100

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 金明江

作者单位： 上海交通大学

项目金额： 25万元

中文摘要： 最近，Science报道了通过析出沉淀降低马氏体相变热滞，从而获得兼具超高可恢复应变能力、高强度以及超宽适用范围的沉淀型超级铁基形状记忆合金。研究者总结了沉淀降低铁基合金马氏体相变热滞的表观规律，但是其内在机制仍未见系统的研究报道。本申请项目拟以FeNiCoTi合金和FeNiCoAlTaB合金为对象，根据相变热滞的能量耗散理论，研究沉淀对相变热滞的影响规律：一方面从降低耗散能量源（马氏体相变共格应变能）的角度，论证沉淀通过调控马氏体正方度，改善A/M界面匹配程度，降低相变过程体系共格应变能的机制；另一方面从能量耗散途径的角度，阐述通过沉淀强化基体、抑制位错滑移，切断相变过程中的能量耗散途径，并获得抑制位错滑移的临界强度。双管齐下，揭示铁基合金马氏体相变由非热弹性转变为热弹性的内在机制。本申请项目的实施对自主研发具有超大可恢复应变能力的新型铁基形状记忆合金具有重要的理论指导意义。

中文关键词： 形状记忆合金；马氏体相变；沉淀相；热滞；界面共格度

英文摘要： Recently, Science reported a series of precipitation hardening Fe-based super shape memory alloys showing very high reversible strain (13.5%), excellent strength (1200MPa) and large operational temperature range (about 400K) through reducing the martensitic transformation hysteresis by introducing precipitation hardening. Researchers have concluded the apparent laws for controlling of the martensitic transformation hysteresis in the Fe-based alloys, but the internal mechanism was not reported yet. This project application intends to investigate the influence of precipitates on the martensitic transformation hysteresis in the precipitation hardening Fe-based shape memory alloys (Fe-Ni-Co-Ti and Fe-Ni-Co-Al-Ta-B alloys), according to the energy dissipation theory of hysteresis. On the one hand, from the view of decreasing the dissipating energy (the coherent strain energy in martensitic transformation), demonstrate the mechanism that the precipitates control the tetragonality of martensite and improve the compatibility of the A/M interface and result in decreasing the coherent strain energy in martensitic transformation, which was considered as the source of the dissipating energy. On the other hand, from the point of inhibiting the path of energy dissipation, study the mechanism that the precipitates strengthen t

英文关键词： shape memory alloy；Martensitic transformation；precipitates；hysteresis；interfacial coherency