45钢激光合金化Mo1B9Crx涂层的组织及性能

Microstructure and properties of laser alloyed MoBCr coating on 45 steel

通过激光合金化技术在45钢基体上制备Mo1B9Crx合金化涂层,研究了Cr含量对涂层组织性能的影响。结果表明,Mo1B9Cr1.1涂层最佳激光合金化工艺为激光功率3.3 kW,扫描速度900 mm/min,搭接率30%;在此工艺条件下,涂层与基体呈良好的冶金结合,无孔洞和裂纹,合金化区组织为Fe-Mo、Fe2B、Fe-Cr、Cr2B、CrxFey固溶体和化合物;随Cr含量从1.1%增加到23.3%,涂层硬度、摩擦因数、磨损率逐渐减小;当Cr含量为1.1%时,涂层硬度最大,为1005 HV0.1;当Cr含量为23.3%时,其耐磨性能最好,摩擦因数为0.475,磨损率为0.574×10^-14m^3/(N·m),涂层磨损形式主要是磨粒磨损和粘着磨损结合的形式。

Mo1B9Crx alloyed coating was prepared on the 45 steel substrate by laser alloying technology.The effect of Cr content on the microstructure and properties of the coating was studied.The results show that the best laser alloying process parameters for Mo1 B9 Cr1.1 coating are laser power of 3.3 kW,scanning speed of 900 mm/min,overlap rate of 30%.By adopting this process,the coating shows a good metallurgical bonding with the substrate without voids and cracks,the alloying zone is composed of Fe-Mo,Fe2 B,Fe-Cr,Cr2 B,CrxFeysolid solutions and compounds,and the coating hardness,friction coefficient,and wear rate gradually decrease when the Cr content increases from 1.1% to 23.3%.When the Cr content is 1.1%,the maximum coating hardness is 1005 HV0.1.When the Cr content is 23.3%,the wear resistance is the best,the friction coefficient is 0.475,the wear rate is 0.574×10^-14m^3/(N·m),and the form of coating wear is mainly a combination of abrasive wear and adhesive wear.