摘要
目的通过对不同吸收层下飞秒激光冲击后Cu箔的显微组织和力学性能变化分析,选出强化效果更好的吸收层。方法利用飞秒激光对覆有百纳米厚度吸收层的铜箔(Cu-nm)和覆有百微米厚度吸收层的铜箔(Cu-μm)进行冲击强化,通过扫描电镜、电子背散射衍射仪、X射线衍射仪、显微硬度计对两个样品进行显微组织和力学性能的观测分析。结果飞秒激光冲击后,Cu-nm主要产生形变孪晶,孪晶比例提高了60.9%,大角度晶界比例提高了12.8%,显微硬度提高了10.8%;Cu-μm主要发生位错变化,位错密度增加16%,小角度晶界比例提高9.8%,显微硬度提高2.2%。除此之外,经飞秒激光冲击后,Cu-nm产生了更大的残余压应力,不仅中和了母材的残余拉应力,还表现为残余压应力;而Cu-μm经飞秒激光冲击后,产生的残余压应力无法完全中和母材的残余拉应力,仍显示为残余拉应力。结论对比研究得出,飞秒激光冲击Cu-nm后,实现了微观组织孪晶化,改变了残余应力状态,提高了铜箔表面的硬度。
By analyzing the microstructure and mechanical properties of Cu foil after femtosecond laser shock in different absorption layers,the absorption layer with better strengthening effect was selected.Femtosecond lasers were used to impact strengthen the copper foil(Cu-nm) coated with a 100 nm thickness absorption layer and the copper foil(Cu-μm) coated with a 100 μm thickness absorption layer.The microstructure and mechanical properties of the two samples were observed and analyzed by scanning electron microscopy,electron backscatter diffraction,X-ray diffraction,and microhardness tester.After femtosecond laser shock,Cu-nm mainly produced deformation twinning,with 60.9% increase in the twinning ratio,12.8%increase in the ratio of large-angle grain boundaries,and 10.8% increase in microhardness;Cu-μm mainly underwent dislocation changes,with 16% increase in dislocation density,9.8% increase in the ratio of small-angle grain boundaries,and 2.2% increase in microhardness.In addition,Cu-nm produces greater residual compressive stress after femtosecond laser shock,which not only neutralizes the residual tensile stress of the base material,but also shows as residual compressive stress,while the residual compressive stress produced by Cu-μm after femtosecond laser shock cannot completely neutralize the residual tensile stress of the base material,and still shows as residual tensile stress.A comparative study showed that the femtosecond laser shock on Cu-nm achieved microstructural twinning,changed the residual stress state and improved the hardness of the copper foil surface.
作者
田甜
张景泉
黄婷
肖荣诗
TIAN Tian;ZHANG Jing-quan;HUANG Ting;XIAO Rong-shi(High-power and Ultrafast Laser Manufacturing Lab,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2021年第12期174-180,共7页
Surface Technology
关键词
飞秒激光冲击
吸收层
显微组织
力学性能
femtosecond laser shock
absorption layer
microstructure
mechanical property
