激光粉床熔融Ti-6Al-4V热处理的研究现状:微观组织演变和耐腐蚀性能  

Current research status on Ti-6Al-4V heat treatment through laser powder bed fusion:microstructure evolution and corrosion resistance

作　　者：朱金岭 程军[3] 陈靓瑜[1,4] ZHU Jinling;CHENG Jun;CHEN Liangyu(School of Material Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China;National Dies and Molds Quality Supervision Test Center,Kunshan 215300,China;Northwest Institute for Nonferrous Metal Research,Shaanxi Key Laboratory of Biomedical Metal Materials,Xi’an 710016,China;Foshan(Southern China)Institute for New Materials,Foshan 528200,China)

机构地区：[1]江苏科技大学材料科学与工程学院,镇江212100 [2]国家模具质量监督检验中心,昆山215300 [3]西北有色金属研究院,西安710016 [4]佛山市(华南)新材料研究院,佛山528200

出　　处：《工程科学学报》2024年第8期1393-1402,共10页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(52271249);陕西省重点研发计划(2023-YBGY-488)。

摘　　要：针对激光粉床熔融Ti-6Al-4V热处理问题,对现有文献进行总结,讨论热处理对激光粉床熔融Ti-6Al-4V的组织和腐蚀行为的影响.围绕组织决定材料性能这一观点,通过扫描电子显微镜观察热处理前后激光粉床熔融Ti-6Al-4V微观组织变化,恒电位极化实验分析耐腐蚀性能的差异,将热处理前后激光粉床熔融Ti-6Al-4V的组织和耐腐蚀性能变化相联系,两者相互比较印证.结果发现,细针状α′马氏体相和残余应力是造成激光粉床熔融Ti-6Al-4V耐腐蚀性能变差的主要原因,适当的热处理可以促进细针状α′马氏体分解,增加体心立方β相,消除残余应力,改善激光粉床熔融Ti-6Al-4V的耐蚀性能.同时,过分的热处理会造成激光粉床熔融Ti-6Al-4V晶粒度的增加,影响钝化膜的稳定性.最后,总结现有结论,对激光粉床熔融Ti-6Al-4V热处理未来发展做出展望.Laser powder bed fusion(LPBF),an additive manufacturing technology,is extensively applied in various fields.In the building process,one or more laser beams scan and melt the powder previously deposited on the build platform,following a prescribed scanning path to achieve the designed three-dimensional geometry.After the current powder layer is selectively melted and solidified,another layer of powder is spread,and the laser scanning continues.Such repetitive operations exhibit inherent rapid heating and cooling characteristics,resulting in uneven microstructures and the accumulation of internal stresses for the produced parts.For the most widely used Ti-6Al-4V,this LPBF characteristic forms fine needle-like α′martensite and small amounts of beta phase.There is a phase potential difference between the α′and the β phases,which constitutes a corrosive galvanic battery,and the corrosion reaction preferentially occurs at the phase interface of the α′and the β phases.However,as a metastable structure,the thermodynamic stability of the α′phase is lower than that of the β phase,which makes theα′phase preferentially corroded.Moreover,the V element enrichment in the β phase imparts stability,exerting a significant inhibitory effect on the corrosion and dissolution of the Ti-6Al-4V alloy.This is evident in the denser and more stable passive film formed on the β phase compared with that on the α′or α phase,accompanied by a corresponding increase in corrosion resistance.To better meet different service conditions,it is imperative to regulate its microstructure and alleviate residual stresses through heat treatment as a heat-treatable α+β type titanium alloy.However,the optimal heat treatment conditions for LPBF Ti-6Al-4V are being determined.We aim to provide a comprehensive overview of the current literature,focusing on the perspective that the properties of a material are inherently influenced by its microstructure.Specifically,the correlation between microstructure and corrosion resistance in LPBF

关 键 词：激光粉床熔融 热处理 钛合金 微观组织 耐蚀性能 

分 类 号：TG142.71[一般工业技术—材料科学与工程]