晶体取向对激光快凝重熔区组织形态的影响  

EFFECTS OF CRYSTAL ORIENTATION ON MICROSTRUCTURES OF MOLTEN POOL DURING LASER SURFACE REMELTING

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

机构地区：[1]清华大学机械工程系,北京100084 [2]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《金属学报》2001年第6期571-574,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目59771054 清华大学985资助项目012-081100500

摘　　要：利用５ｋＷ ＣＷ ＣＯ２激光器对ＤＤ２单晶合金进行了表面重熔实验，研究了基材晶体取向对重熔区微观组织生长方向的影响结果表明：熔池中微观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．在同一晶面上，沿不同晶向进行扫描时，重熔区组织生长方向明显不同．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．Detailed experimental researches on the effects of crystallography of matrix on the microstructure evolution of the laser molten pool during solidification were carried out with a DD2 single crystal specimen by using a 5 kW CO2 laser. The experimental results show that the crystallographic direction of matrix can obviously influence the direction of dendrite growth and crystallographic effects are greater than that of heat flux during dendrite growth. On the same crystal face, the microstructures in the molten pool are very different when laser beam scanning along different crystal orientation.

关 键 词：激光表面熔凝 熔池显微组织 晶体取向 镍合金 

分 类 号：TG166.7[金属学及工艺—热处理] TG111.4[金属学及工艺—金属学]