激光冲击强化对激光增材制造TC4钛合金组织和性能的影响  

Effect of Laser Shock Peening on Microstructure and Properties of Laser Additive Manufactured TC4 Titanium Alloy

作　　者：陈雪鹏 张凌峰[1,2] 熊毅 罗高丽[1] 武永丽 Chen Xuepeng;Zhang Lingfeng;Xiong Yi;Luo Gaoli;Wu Yongli(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,Henan,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,Henan,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳471023

出　　处：《中国激光》2022年第16期155-163,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(U1804146,52111530068)。

摘　　要：通过对激光增材制造(LAM)TC4钛合金表面进行激光冲击强化(LSP),对比研究了LSP处理对LAM-TC4钛合金微观组织、力学性能和断口形貌的影响。LAM-TC4钛合金的原始组织由大量粗大的α板条及一定数量的板条间β相构成。经LSP处理后,表层组织在高能冲击波的作用下,原始粗大的α板条破碎细化,形成了大量位错和形变孪晶,导致晶格畸变。LSP处理使LAM-TC4钛合金的残余应力由残余拉应力转变成残余压应力。LSP处理后LAM-TC4钛合金表面存在的最大残余压应力为-190 MPa,显微硬度提高了16.5%,显微硬度随深度的增加而减小。此外,经LSP处理后,LAM-TC4钛合金的屈服强度和抗拉强度较LSP处理前分别提高了46.3%和32.3%,塑性基本维持不变。LSP处理可使LAM-TC4钛合金获得更好的强度和塑性匹配。Objective TC4 titanium alloy is widely used in the aerospace industry due to its high specific strength and good heat and corrosion resistance.Laser additive manufacturing has the advantages of digital design and manufacturing integration,which can greatly improves the utilization rate of raw materials and is particularly suitable for manufacturing the structural parts of titanium alloy.It has become one of the core technologies to enhance the design and manufacturing capability of highperformance complex components.However,during laser additive manufacturing of titanium alloy,there exists a large temperature gradient between the melt pool and the substrate,which results in the poor comprehensive mechanical properties of formed parts.Therefore,it is very important to find a suitable method to improve the comprehensive mechanical properties and extend the service life.Laser shock peening(LSP)is an important method for the post-treatment of metal parts,which uses a high-power short-pulse laser on the surface of the material to produce compressive residual stresses and work hardening layers,and thus it possesses the outstanding advantages of controllability and significant strengthening effect.In this paper,the effect mechanism of LSP on the microstructure and properties of laser additive manufactured TC4(LAM-TC4)titanium alloy is systematically investigated by adopting the LSP surface treatment.It is expected to first improve the mechanical properties of the surface layer of the LAM-TC4 titanium alloy,then improve the comprehensive mechanical properties,and finally provide an experimental basis for optimizing the microstructure and mechanical properties of LAM-TC4 titanium alloy.Methods In this work,LSP is first applied to the surface of the LAM-TC4 titanium alloy.Then,the physical phases of block samples before and after LSP are analyzed by the X-ray diffractometer(XRD),and the microstructures of block samples before and after LSP are observed by the optical microscope(DM).The block samples before and after LSP ar

关 键 词：激光技术 激光增材制造 激光冲击强化 钛合金 微观组织 力学性能 断口形貌 

分 类 号：TN249[电子电信—物理电子学]