激光高速应变对双态组织近α型Ti-6Al-3Nb-2Zr-1Mo合金组织与性能的影响  

Effect of laser high-speed strain on microstructure and properties of nearα-type Ti-6Al-3Nb-2Zr-1Mo alloy with bimodal microstructure

作　　者：张镜 张凌峰[1,2] 熊毅 姚怀[1,2] 罗高丽 陈雪鹏[1] ZHANG Jing;ZHANG Ling-feng;XIONG Yi;YAO Huai;LUO Gao-li;CHEN Xue-peng(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,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：《塑性工程学报》2025年第1期168-176,共9页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(U1804146,51801054);河南省高校科技创新人才支持计划(17HASTIT026)。

摘　　要：利用激光冲击强化使Ti-6Al-3Nb-2Zr-1Mo(Ti80)合金表面产生严重塑性变形,借助SEM、TEM和XRD等方法深入研究了表面严重塑性变形对Ti80合金显微组织、力学性能以及耐腐蚀性能的影响。结果表明:激光冲击强化使Ti80合金表面产生无相变的严重塑性变形层,表层晶粒内部产生大量位错胞、位错墙、位错缠结等晶体缺陷。此外,通过位错间的相互作用,表面粗大晶粒细化至纳米级。晶粒细化和晶粒内高密度位错严重阻碍了位错的运动,从而增加了样品的硬度和强度。与原始试样相比,LSP处理试样的表面显微硬度提高了16.5%,产生了386.4 MPa的高幅残余压应力,在不牺牲延展性的前提下提高了强度。电化学和静态浸泡实验结果表明,LSP处理后试样的自腐蚀电位增加了77.7 mV vs.SCE,腐蚀电流密度和腐蚀速率分别降低了1.358μA·cm^(-2)、0.08 mm·year^(-1),点蚀和晶间腐蚀现象减弱。这是由于LSP处理后样品晶粒得到细化,增强了表面结构的稳定性并提供了更多钝化膜的形核位点,从而提高了Ti80合金的耐腐蚀性能。The severe plastic deformation on the surface of Ti-6Al-3Nb-2Zr-1Mo(Ti80)alloy was induced by laser shock peening(LSP).The effects of severe plastic deformation on the microstructure,mechanical properties and corrosion resistance of Ti80 alloy were studied in depth by means of SEM,TEM and XRD.The results show that LSP causes the severe plastic deformation layer without phase transformation on the surface of Ti80 alloy,and a large number of crystal defects such as dislocation cells,dislocation walls and dislocation tangles are generated inside the surface grains.Moreover,through the interaction between the dislocations,the surface coarse grains are refined to nanoscale level.The grain refinement and the high density of dislocations within the grains severely hinder the movement of the dislocations,thereby increasing the hardness and strength of the samples.Compared with the original samples,the surface microhardness of the samples after LSP treatment is increased by 16.5%,and the high amplitude residual compressive stress of 386.4 MPa is generated,which increases the strength without sacrificing ductility.The results of electrochemical and static immersion experiments show that the corrosion potential of samples after LSP treatment increases by 77.7 mV vs.SCE,the corrosion current density and corrosion rate decrease by 1.358μA·cm^(-2) and 0.08 mm·year^(-1),respectively,and the pitting and intergranular corrosion phenomenon is weakened.This is due to the fact that the grains of samples are refined after LSP treatment,which enhances the stability of the surface structure and provides more nucleation sites for passivation films,thus the corrosion resistance of Ti80 alloy is improved.

关 键 词：激光冲击强化 Ti-6Al-3Nb-2Zr-1Mo合金 微观结构 残余应力 力学性能 耐腐蚀性能 

分 类 号：TH142.2[一般工业技术—材料科学与工程]