Ni基合金+WC激光熔覆层再加热时的显微组织变化特性  

Microstructure Change Characteristic of Reheating Up Laser Cladding Coating of Ni- based Alloy In Addition With WC

作　　者：刘喜明[1] 

机构地区：[1]长春工业大学材料表面工程研究所,长春130012

出　　处：《应用激光》2006年第6期381-384,380,共5页Applied Laser

基　　金：吉林省杰出青年基金项目(20030128);吉林省工业引导项目(20030331)资助

摘　　要：采用Ni基自熔合金+块状WC混合粉末进行送粉激光熔覆并获得熔覆层,对熔覆层在不同温度下加热后空冷至室温,观察相应熔覆层的显微组织变化,结果表明：Ni基自熔合金+WC送粉激光熔覆层不适合在500℃～900℃再加热处理,再此温度区间对熔覆层再加热会导致块状WC出现裂纹。Ni基自熔合金基体的显微组织在700℃以上开始不稳定,发生形态和显微组织结构的变化。熔覆层中的块状WC加热至900℃以上时裂纹会被自行焊合,温度继续升高,块状WC会发生离散,分化成细小的WC颗粒,产生这种现象的根本原因是块状WC具有先天的超细纤维、颗粒混合结构。The laser cladding with feeding powder were performed by using Ni - based alloy in addition with the massive WC mix powder. After the cladded coating were coolled in air to room - temperature from different temperature,observed the change of microstreture. The result showed that cladded coating were not to suit in 500℃～900 ℃ reheating up,for the massive WC would appear crack and the shape of Ni - based ahoy substrate＇ s microstructure would change and became instability over 700℃. Due to innate superfine fibre and pellet composite structure, the crack would auto welded together when the massive WC were heating up to 900℃ ,and with the temperature rising, the massive WC turned into the tiny WC pellet.

关 键 词：送粉激光熔覆 Ni基自熔合金+块状WC 再加热 显微组织 

分 类 号：TG174.442[金属学及工艺—金属表面处理]