工件形状对镍基高温合金激光再制造应力场分布的影响  

Influence of Repair Cross Section on Stress-Field Distribution in the Nickel-Based Superalloy Laser Remanufacturing

作　　者：王凯[1] 赵剑峰[1] 潘浒[1] 刘云雷[1] 

机构地区：[1]南京航空航天大学机电学院,江苏南京210016

出　　处：《激光与光电子学进展》2013年第4期119-126,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51205198);中国博士后科学基金面上资助项目(2012M511266);江苏省博士后科研资助计划(1102052C)资助课题

摘　　要：利用Marc软件对基于同轴送粉的镍基高温合金GH4169零件表面修复过程进行了数值模拟,通过热-机直接耦合分析了不同的修复截面形状对激光熔覆过程中温度场/残余应力场的分布的影响。结果表明,对于单道的激光表面修复,修复截面形状的不同将导致在结合面处的温度场/残余应力场的分布也呈现出不同的特点:直接在平面上修复时,残余应力平行于扫描路径上的分量明显大于其垂直分量;在修复截面为矩形或弧形凹坑时,由于熔覆材料受到凹坑两侧面的约束作用,残余应力垂直于扫描方向的分量相对于平面上直接修复时明显增加,且随着深宽比的增加,垂直分量对平行分量的比值也有进一步增大的趋势,但在同深宽比情况下,弧形凹坑的比值较小。为避免薄壁零件的变形,预处理时宜采用深宽比较小的弧形修复截面。A numerical simulation of laser cladding process on the surface of nickel-based superalloy GH4169 with coaxial powder feeding system is carried out by Marc software. The influence of different repair cross sections on the distribution of temperature and residual stress field is studied through a directly coupled thermo-mechanical analysis. The results show that for single-path laser surface reparation, different repair cross sections lead to different distribution characteristics of temperature and residual stress field in the bonding zone. The parallel component of residual stress is evidently larger than vertical component in the direction of the scanning path when it is repairing on a plane. The vertical component of residual stress is relatively increased due to the constraints from two sides of the crater when it is repairing a crater of a long strip with rectangular or arc-shaped cross section. As the aspect ratio of the section increases, the ratio of vertical component of residual stress to parallel component also increases. However, the ratio of vertical component of residual stress to parallel component for arc-shaped cross section is smaller for the same aspect ratio. In order to avoid the deformation of the thin-walled parts, an arc-shaped cross section with small aspect ratio is recommended.

关 键 词：激光技术 再制造 残余应力 有限元方法 激光熔覆 

分 类 号：TN249[电子电信—物理电子学] TG174.44[金属学及工艺—金属表面处理]