摘要
目的研究激光冲击强化处理对ZL205A铝合金表面完整性和力学性能的影响规律,改善材料的残余应力状态,提高材料的力学性能。方法利用激光共聚焦显微镜、扫描电子显微镜、X射线衍射仪对激光冲击前后试样的表面形貌与微观组织进行分析,通过显微硬度、纳米压痕和拉伸性能测试方法,对ZL205A铝合金激光冲击处理前后试样的硬度、纳米硬度和拉伸性能进行评价。结果ZL205A铝合金经过激光冲击处理后,表面粗糙度增加至(3.798±0.46)μm,同时在表层形成深度约为5μm、平均晶粒尺寸为100nm的纳米级晶粒,形成梯度结构。在基体表层引入了较大的残余压应力,最大残余应力达到–140.2MPa,表面显微硬度由(146.6±5.64)HV0.1增加至(173.8±8.87)HV0.1,经过纳米压痕测试可知,材料截面最大弹性模量为2.49GPa,极限抗拉强度、屈服强度、延伸率均增加,材料的力学性能得到提高。结论激光冲击强化处理使ZL205A铝合金表层发生塑性变形,细化了表层晶粒组织,提高了ZL205A铝合金基体的残余压应力、显微硬度、弹性模量,并有效提高了ZL205A铝合金的力学性能。
The work aims to study the effects of laser shock peening treatment on the surface integrity and mechanical prop-erties of ZL205A aluminum alloy,so as to improve the residual stress state and mechanical properties of the material.The sur-face morphology and microstructure of ZL205A aluminum alloy before and after laser shock were analyzed by laser confocal microscope,scanning electron microscope and X-ray diffractometer.The hardness/nano-hardness and tensile properties of ZL205A aluminum alloy samples before and after laser shock were evaluated by means of microhardness,nano-indentation and tensile properties.After laser shock treatment,the surface roughness of ZL205A aluminum alloy increased to(3.798±0.46)μm.At the same time,nanoscale grains with a depth of about 5μm and an average grain size of 100 nm were formed on the surface,forming a gradient structure.A large residual compressive stress was introduced into the surface layer of the matrix.The maxi-mum residual stress reached-140.2 MPa.The surface microhardness increased from(146.6±5.64)HV0.1 to(173.8±8.87)HV0.1.The cross section of the material was tested by nanoindentation,and the maximum elastic modulus was 2.49 GPa.The ultimate tensile strength,yield strength and elongation increased,and the mechanical properties of the material were improved.The laser shock peening process can make the surface layer of ZL205A aluminum alloy plastic deformation,refine the surface grain structure,improve the residual compressive stress,microhardness and elastic modulus of ZL205A aluminum alloy matrix,and effectively improve the mechanical properties of ZL205A aluminum alloy.
作者
邢泽宙
鲁辉虎
沈兴全
辛志杰
赵宇芳
秦皓
韩建杉
杨冰
XING Zezhou;LU Huihu;SHEN Xingquan;XIN Zhijie;ZHAO Yufang;QIN Hao;HAN Jianshan;YANG Bing(School of Mechanical Engineering,North University of China,Taiyuan 030051,China;Shanxi Key Laboratory of Intelligent Equipment Technology in Harsh Environment,Taiyuan 030051,China)
出处
《精密成形工程》
北大核心
2024年第8期77-84,共8页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52105408)
山西省青年基金(20210302124205)。
