Ni-Co-Mn-Sn-Gd磁性形状记忆合金微观组织、力学性能和耐腐蚀性能  

Microstructure,mechanical properties and corrosion resistance properties of Ni-Co-Mn-Sn-Gd magnetic shape memory alloys

作　　者：高丽[1] 胡少辉 辛向阳 廖华玉 刘紫莉 徐阳睿 GAO Li;HU Shaohui;XIN Xiangyang;LIAO Huayu;LIU Zili;XU Yangrui(College of Engineering Science and Technology,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]上海海洋大学工程学院,上海201306

出　　处：《材料工程》2023年第6期111-119,共9页Journal of Materials Engineering

基　　金：国家青年科学基金资助项目(51401122)。

摘　　要：Ni-Mn-Sn合金被认为是最具潜力的制冷工质、传感器、驱动器材料之一,但由于金属间化合物的本征脆性很大程度阻碍了其实际应用。采用扫描电子显微镜(SEM)、差示扫描量热仪(DSC)、电子万能力学试验机和电化学工作站系统研究了Ni_(45)Co_(5)Mn_(38)Sn_(12-x)Gd_(x)(x=0.3,0.6,1,1.5,原子分数/%,下同)磁性形状记忆合金的微观组织、马氏体相变、力学性能和耐海水腐蚀性。结果发现,稀土元素Gd含量为0.3%时,出现了斑状析出相,同时在斑状析出相周围还发现一种颗粒状析出相,随着Gd掺杂量的不断增加,两种析出相逐渐增多并连接在一起呈网状分布。Gd的掺杂使合金基体价电子浓度升高,进而使得合金相变温度升高。同时,Gd含量增多会提高合金的力学性能,Gd含量为1.5%时,合金的压缩断裂强度可达1258 MPa,压缩断裂应变可达13.7%。此外,Ni-Co-Mn-Sn-Gd合金的耐海水腐蚀性能优于304不锈钢,而且随着Gd含量的增加,合金的耐腐蚀性能也逐渐增强。Ni-Mn-Sn alloy is considered to be one of the most potential refrigerant,sensor and driver materials,but its practical application is hindered to a large extent due to the inherent brittleness of intermetallic compounds.The microstructure,martensitic transformation,mechanical properties and seawater corrosion resistance of Ni_(45)Co_(5)Mn_(38)Sn_(12-x)Gd_(x)(x=0.3,0.6,1,1.5,atom fraction/%,the same below)magnetic shape memory alloy were studied by scanning electron microscopy(SEM),differential scanning calorimetry(DSC),electron universal capacity testing machine and electrochemical workstation.The experimental results show that when the content of Gd is 0.3%,a mottled precipitate phase appears,and a particle precipitate phase is found around the mottled precipitate phase.The two precipitates increase gradually and are connected together in a network distribution.The doping of Gd increases the concentration of valence electrons in the alloy matrix,which leads to the increase of the alloy martensitic transformation temperature.When Gd content is 1.5%,the compressive strength of the alloy can reach 1258 MPa and the compressive fracture strain can reach 13.7%.In addition,the corrosion resistance of Ni-Co-Mn-Sn-Gd alloy is better than that of 304 stainless steel,and the corrosion resistance of the alloy gradually increases with the increase of Gd content.

关 键 词：力学性能 微观组织 马氏体相变 耐腐蚀性能 Ni-Co-Mn-Sn-Gd磁性形状记忆合金 

分 类 号：TG139[一般工业技术—材料科学与工程]