锰基高温反铁磁形状记忆合金中马氏体逆相变的表面浮突研究  

Study on surface relief related to reverse martensitic transformation in Mn-based high-temperature antiferromagnetic shape memory alloy

作　　者：元峰 刘川[1] 耿正[1] 崔严光[1] 王林[1] 万见峰[1] 张骥华[1] 戎咏华[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240

出　　处：《物理学报》2015年第1期240-246,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51171112);国家重点基础研究发展计划(973项目)(批准号:2012CB619400);教育部国家级大学生创新创业训练计划项目(批准号:201310248037)资助的课题~~

摘　　要：本文利用原子力显微镜原位研究Mn79.5Fe15.6Cu4.9反铁磁高温形状记忆合金在升降温过程中与马氏体相变相关的表面起伏特征,同时采用X射线衍射、动态热机械分析等实验检测手段辅助分析其微观组织结构演化,从纳米尺度分析面心立方—面心四方结构相变及表面浮突产生的物理机理.实验结果表明:在升降温过程中观察到帐篷型表面浮突,由面心立方—面心四方马氏体逆相变产生的,即母相浮突,这与通常观测到的马氏体浮突不同;实验证实面心立方—面心四方马氏体逆相变具有切变特征,马氏体孪晶的逆向切变是产生帐篷型表面浮突的主要机理;测得逆孪晶切变的浮突角小于1?,远小于传统形状记忆合金的表面浮突角值,这是由于面心立方母相与面心四方马氏体相结构差异较小造成的;表面浮突随温度变化具有极好的可逆性,这是马氏体相变晶体学可逆性决定的,表明该合金具有优良的表面形貌记忆效应.Evolution of surface relief and its intrinsic mechanism associated with martensitic transformation （MT） during heating and cooling in Mn79.5Fe15.6Cu4.9 high-temperature antiferromagnetic shape memory alloy （SMA） have been investigated in nano-scale by means of in-situ atomic force microscopy （AFM）, X-ray diffraction （XRD）, and dynamic mechanical analyzer （DMA）. Experimental results show that the N-type surface relief originates from the reverse MT and is completely made of matrix which is different from the conventional ones. The reverse MT exhibits untwinning shear and the reverse shearing of twinned martensites mainly contribute to the surface relief. The measured surface relief angles are less than 1°, which are determined by the small difference of lattice constants between fcc and fct structures. Surface relief has a good recovery property because of the crystallographic reversibility rule in SMAs, implying that this kind of alloy has a good surface morphology memory effect.

关 键 词：表面浮突 原位原子力显微镜 马氏体逆相变 Mn-Fe-Cu反铁磁合金 

分 类 号：TG139.6[一般工业技术—材料科学与工程]