SiC含量对激光熔覆SiC/Ni60A复合涂层显微组织和耐磨性能的影响

利用LDM2500-60半导体激光器在45#钢板上制备SiC颗粒增强Ni60A合金激光熔覆涂层,系统研究SiC含量对涂层的显微组织、稀释率、耐磨性、摩擦因数和显微硬度的作用规律。结果表明:随着SiC含量增加,熔覆表层的微观组织细化,稀释率、耐磨性、摩擦因数和硬度均先增加后降低;当SiC含量为20%(质量分数,下同)时,熔覆层的耐磨性能最佳,磨损量仅为0.0012g,为基体磨损量的1/36.3;摩擦因数最小为0.464,且磨损过程最为平稳;熔覆层平均硬度值最高,达到1039.9HV0.2,为基体的3.5倍;但当SiC含量达到25%时,熔覆层的显微硬度与耐磨性能反而下降。

Effect of SiC Content on Microstructure and Wear Resistance of Laser Cladding SiC/Ni60A Composite Coating

The SiC reinforced Ni60A alloy laser cladding coating on the 45 steel substrate was fabricated with the LDM2500-60 semiconductor laser equipment.The effect of SiC content on microstructure,dilution rate,wear resistance,friction coefficient and microhardness was investigated systematically.The results show that with the increase of SiC content,the microstructure of upper coating is refined obviously,the dilution rate,wear resistance,friction coefficient and microhardness increase firstly and then decrease;when the mass fraction of SiC is 20 ％,the wear resistance of the cladding coating is the best one,in which the wear loss of coating is only 0.0012g and is 1/36.3 of the matrix;the minimum friction coefficient is 0.464,the friction process is the most stable;the highest microhardness of the cladding coating is 1039.9HV0.2,which is 3.5 times of the substrate;but when the mass fraction of SiC is 25％,the microhardness and wear resistance of coating decrease.