激光熔化沉积成形Cu-Al-Mn-Ti形状记忆合金组织与性能研究  

Microstructure and properties of laser melting deposited formde Cu-Al-Mn-Ti shape memory alloy

作　　者：刘旭 涂燕玲 胡碧艳 游新月 汪龙霞 宋王翼 邵君麒 邓声华[1] 李瑞迪[2] LIU Xu;TU Yanling;HU Biyan;YOU Xinyue;WANG Longxia;SONG Wangyi;SHAO Junqi;DENG Shenghua;LI Ruidi(Faculty of Materials Metallurgy and Chemistry,Jaingxi University of Science and Technology,Ganzhou 341000,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000 [2]中南大学粉末冶金国家重点实验室,长沙410000

出　　处：《有色金属材料与工程》2023年第5期60-67,共8页Nonferrous Metal Materials and Engineering

基　　金：赣州市科技计划项目(赣市科发[2019]60号);江西理工大学大学生创新创业训练计划项目(DC2021-013)。

摘　　要：采用激光熔化沉积(laser melting deposition,LMD)成形Cu-Al-Mn-Ti形状记忆合金,研究其组织、冶金缺陷与性能特点。研究表明,LMD成形Cu-Al-Mn-Ti合金的显微组织具有各向异性特征:建造面为柱状晶组织,扫描面为等轴晶组织。这是由于LMD成形过程沉积方向存在较大的温度梯度导致的。LMD成形Cu-Al-Mn-Ti合金的基体组织为β相板条马氏体,并存在大量Cu2AlMn颗粒状析出相。孔隙缺陷是LMD成形Cu-Al-Mn-Ti合金中主要的冶金缺陷,严重影响了合金的力学性能。热处理可提高LMD成形Cu-Al-Mn-Ti合金的力学性能及形状记忆性能。固溶、时效处理后,LMD成形Cu-Al-Mn-Ti合金的抗拉强度可由453.6 MPa提高至519.5 MPa,形状回复率可由68%提高至97%;当时效温度为500℃时,在晶界上开始析出网状α相导致Cu基体中的Al含量增加,使合金的力学性能和形状回复率下降。The laser melting deposition(LMD)technique was applied to prepare the Cu-Al-Mn-Ti shape memory alloy.The microstructure and properties of LMD formed Cu-Al-Mn-Ti alloy were investigated.The results show that the LMD Cu-Al-Mn-Ti alloy has an anisotropy microstructure:the columnar crystals at the building plane and the equiaxed grains at the scanning plane.This should be attributed to the large temperature gradient in the building direction that formed during LMD.The structure of the LMD Cu-Al-Mn-Ti alloy is the lath martensite withβas the matrix,and there exists large number of Cu2AlMn particles precipitated in the alloy.Pores are the main metallurgical defect in the LMD Cu-Al-Mn-Ti alloy that influences the mechanical properties.The mechanical properties and shape memory performance of the Cu-Al-Mn-Ti alloy can be significantly improved by heat treatment.After solution and aging,the ultimate tensile strength of the alloy is increased from 453.6 MPa to 519.5 MPa,the shape recovery ratio can be increased from 68%to 97%.When the aging temperature reaches 500℃,the meshedαphase precipitates at the grain boundary,leading to the increase of the Al content in the alloy matrix,which consequently results in the reduction of the mechanical property and shape recovery ratio.

关 键 词：激光熔化沉积 Cu-Al-Mn-Ti合金 形状记忆 显微组织 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]