激光表面快速熔凝过程中熔区组织重构  

Reconstruction of Molten Pool During Laser Surface Remelting

作　　者：杨森[1,2] 黄卫东[3] 刘文今[1] 苏云鹏[3] 周尧和[3] 

机构地区：[1]清华大学机械系 [2]西北工业大学凝固技术国家重点实验室西安710072 [3]西北工业大学凝固技术国家重点实验室

出　　处：《应用激光》2001年第4期225-228,224,共5页Applied Laser

基　　金：国家自然科学基金 (5 97710 5 4) ;清华大学 985重点基金资助项目

摘　　要：利用晶体生长的最小过冷度判据 ,对单晶合金激光重熔区组织的生长速度进行了分析 ,建立了枝晶尖端生长速度与激光束扫描速度和固液界面前进速度的关系。根据此分析对熔池进行了重构和预测 ,发现激光熔池中枝晶组织的生长方向强烈地受基材晶粒取向和激光束扫描方向的影响。枝晶生长条件下 ,择优取向对枝晶生长方向的影响要较热流的影响大。理论预测与实验结果相吻合。A growth velocity analysis was carrid out during laser surface remelting processing based on a minimum velocity or minimum undercooling criterion and the relationships between dendrite growth velocities in the three <100> direction,moving velocities of the solid/liquid interface and laser scanning velocities for the different crystallographic orientation were also set up. The analysis results show that crystallographic effects can influence dendrite growth by favoring growth along a preferred crystallographic direction. According to this analysis,the molten pool shapes were reconstructed and predicted, which was agreement with the experimental results.

关 键 词：激光表面熔凝 组织重构 熔凝过程 晶体 

分 类 号：TN249[电子电信—物理电子学]