定向凝固Ni_(47)Mn_(32)Ga_(21)多晶合金的结构、相变及磁特性  

Structure,phase transformation and magnetic properties in polycrystalline Ni_(47)Mn_(32)Ga_(21) directionally solidified alloy

作　　者：蔡培阳[1] 冯尚申[1] 薛双喜[1] 陈卫平[1] 周英[1] 吴建波[1] 王古平[1] 

机构地区：[1]台州学院物理与电子工程学院,台州318000

出　　处：《中国有色金属学报》2011年第11期2869-2874,共6页The Chinese Journal of Nonferrous Metals

基　　金：浙江省科技厅重点项目(2006C21085);台州市科技计划项目(08KY11)

摘　　要：采用定向凝固方法制备了Ni47Mn32Ga21多晶合金,通过XRD谱和金相照片研究合金的结构,通过对合金磁化强度与温度关系、电阻与温度关系、磁化曲线和磁感生应变曲线的测量分析,研究了合金的相变、磁化特性及磁感生应变特性。结果表明:Ni47Mn32Ga21合金在室温(298K)时为四方结构马氏体相,晶格参数a=b=0.593 8 nm,c=0.553 1 nm。合金的马氏体相变起始温度Ms和终止温度Mf分别为309 K和295 K,逆马氏体相变起始温度As与终止温度Af分别为306 K和319 K,居里温度TC为365 K。室温无压力下,Ni47Mn32Ga21合金有较好的双向可恢复磁感生应变,其饱和磁感生应变值达到-700×10-6。Ni47Mn32Ga21 polycrystalline alloy was prepared by the directional solidification technique.The structure of the alloy were investigated using XRD and metallography methods.The phase-transformation,magnetization properties and magnetic-field-induced strains were also studied through analyzing the magnetization as a function of temperature,the resistance as a function of temperature,magnetization and magnetic field-induced strain curves.The results show that Ni47Mn32Ga21 alloy exhibits martensitic phase of a tetragonal structure with lattice parameters a=b=0.593 8 nm and c=0.553 1 nm at room temperature（298 K）.The martensitic start temperature Ms and the martensitic finish temperature Mf are 310 K and 295 K,respectively.The austenitic start temperature As and austenitic finish temperature Af are 306 K and 319 K,respectively.The Curie temperature of alloy TC is 365 K.Ni47Mn32Ga21 alloy exhibits excellent free recoverability of the magnetic-field-induced strains at room temperature without external stress.The saturated value of magnetic-field-induced strain reaches -700×10-6.

关 键 词：NI-MN-GA合金 定向凝固 马氏体相变 形状记忆合金 磁感生应变 

分 类 号：TG139.6[一般工业技术—材料科学与工程]