摘要
在热作模具钢H13基体上通过激光熔覆制备出TiC/H13复合涂层,研究不同TiC含量对复合涂层抗回火(600℃)性能的影响。利用扫描电镜、能谱仪和显微硬度计对激光熔覆涂层回火前后的组织、成分、硬度进行了对比分析和测试。TiC质量分数小于25 wt.%时,涂层与基体之间保持良好的结合,没有出现明显缺陷,当质量分数为25 wt.%时,颗粒周围出现微裂纹。能谱分析表明复合涂层中的颗粒主要成分是Ti和C。激光熔覆TiC/H13复合涂层回火处理10h和回火前对比,晶粒明显长大,随着TiC含量增加,涂层晶粒越细小,TiC弥散分布于晶界处,抑制枝晶的生长,起到细化晶粒的效果;回火20h和回火10h的对比发现晶粒长大不明显。硬度测试显示随着TiC质量分数的增加,熔覆层硬度明显增加,回火后仍保持很高的硬度。
TiC/H13 composite coating was prepared by semiconductor laser cladding on hot-work die steel H13. The influence of TiC content on tempering （600＂C） resistance of composite coating was researched. Microstructure, phase composition and microhardness of the coatings before and after tempering experiments were examined by SEM, EDS and Vicker microhardness tester. When TiC content was less than 25wt. %0, the coating and the substrate maintained good bonding and no obvious defects, but when content was 25 wt. %, micro-cracks appeared around the particles. EDS showed that the major components of particles in the cladding coating were Ti and C. After tempering 10 hours, the grain of TiC/H13 composite coating grew significantly, with more TiC content, the grain of coating after tempering was more fine. TiC was found to be dispersed in grain boundaries, hinder the growth of dendrites. Compared results of tempering 20h with tempering 10h, it is found that the growth of grains was not obvious. Microhardness curves showed that with the increasing of TiC content, the microhardness of cladding layer increased significantly, while maintained high hardness after tempering.
出处
《应用激光》
CSCD
北大核心
2010年第6期451-455,共5页
Applied Laser
基金
浙江省自然科学基金资助项目(项目编号:Y4090451)
