添加钽对电弧熔丝增材制备镍钛形状记忆合金组织性能的影响  

Effect of Adding Tantalum on Microstructure and Properties of NiTi Shape Memory Alloy Manufactured by Wire Arc Additive Manufacturing

作　　者：左新德 陈懿 李洋[1] 罗震[1] 敖三三[1] ZUO Xinde;CHEN Yi;LI Yang;LUO Zhen;AO Sansan(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350

出　　处：《上海交通大学学报》2024年第3期382-390,共9页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金(U1933129,U21B2079);天津市自然科学基金(19JCZDJC39000)资助项目。

摘　　要：NiTiTa三元形状记忆合金(SMAs)是潜在的生物医用材料,且电弧增材制造(WAAM)技术已经广泛应用于NiTi合金的研究中,研究Ta添加对WAAM的NiTi合金组织性能的影响具有重要意义.利用WAAM技术分别制造了5层NiTi合金和NiTiTa合金薄壁构件,系统研究了Ta添加对NiTi合金的微观组织、相变行为、力学性能以及抗腐蚀能力的影响.结果表明,与NiTi合金相比,NiTiTa合金的晶粒显著细化,析出相由NiTi合金中的Ni3Ti转变为Ni(Ti,Ta)_(2).此外,其相变温度显著提高,导致了室温下的组织由完全奥氏体相(B2)转变为奥氏体(B2)和马氏体(B19’)的混合相.拉伸试验结果表明,NiTiTa合金试样相较于NiTi合金试样的抗拉强度提升了9.5%,但延伸率下降了6.8%.极化曲线结果表明,NiTiTa合金具有更高的自腐蚀电位和更小的腐蚀电流密度,抗腐蚀能力显著提升.本研究为促进WAAM制备的NiTiTa合金及其在生物医疗领域的应用奠定了研究基础.NiTiTa ternary shape memory alloy is a potential biomedical material,and wire arc additive manufacturing(WAAM)technology has been widely used in the research of NiTi alloys.It is of great significance to study the effect of Ta addition on the microstructure and properties of WAAM NiTi alloys.In this paper,5-layer NiTi and NiTiTa alloy walls were fabricated by WAAM technology,and the effects of Ta addition on the microstructure,phase transformation behavior,mechanical properties and corrosion resistance of NiTi alloys were systematically studied.The results show that the grains of the NiTiTa alloy are remarkably refined compared with NiTi alloys,and the precipitation phase of NiTiTa alloy changes from Ni 3Ti of NiTi alloy to Ni(Ti,Ta)_(2).In addition,the phase transition temperature of the NiTiTa alloy is significantly increased,which makes the phase at room temperature change from the complete austenite phase(B2)to a mixed phase of austenite(B2)and martensite(B19′).Tensile tests show that the tensile strength of NiTiTa samples is increased by 9.5%compared with NiTi samples,but the elongation is decreased by 6.8%.The polarization curve results show that the NiTiTa alloy has a higher corrosion potential and a lower corrosion current density,which means a significantly improved corrosion resistance.This paper lays a theoretical foundation for promoting the application of NiTiTa alloys fabricated by WAAM technology in the biomedical field.

关 键 词：镍钛钽合金 电弧增材制造 显微组织 相变行为 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程] TG457[金属学及工艺—焊接]