超细VC对激光熔覆H13合金显微组织和耐磨性的影响

目的 通过添加超细VC颗粒改善Q235合金表面激光熔覆H13涂层的显微组织,并提高其耐磨性.方法 利用激光熔覆技术在Q235表面制备了H13/VC复合涂层,利用光学显微镜、扫描电镜、显微硬度仪以及摩擦磨损试验仪,研究了超细VC颗粒不同添加量对涂层微观结构、显微硬度和摩擦磨损性能的影响.结果 激光熔覆H13/VC复合涂层...

Effect of Ultra-fine VC on Microstructure and Wear Resistance of Laser Cladded H13 Alloy

The work aims to improve the microstructure and wear resistance of laser cladded H13 coating on Q235 alloy by adding ultrafine VC particles.H13/VC composite coating was prepared on Q235 surface by laser cladding.The effects of different amount of ultrafine VC particles on microstructure,microhardness and wear properties of the coating were studied by optical microscope(OM),scanning electron microscope(SEM),microhardness tester and friction tester.The results show that the laser cladded H13/VC composite coatings were metallurgically bonded to the substrate,without obvious pores and cracks.The ultra-fine VC particles were completely dissolved in the laser cladding process,which significantly changed the micro characteristics of the coating.There was no obvious segregation of V element,but with the increase of ultra-fine VC content,the content of V element in dendrite stem and inter dendrite showed an increasing trend.The ultra-fine VC particles play the role of solution strengthening,and the microhardness of the cladding layer increased with the increase of VC content.The average microhardness of H13 cladding layer is 504.21HV_0.3,with the increase of ultra-fine VC content,the microhardness of the composite coating increases gradually(608.21,658.24,680.41HV_0.3).The wear volume of H13 cladding layer is 3.97×10^?2mm³.When the VC content is 2%,the wear resistance of H13 alloy is higher that H13 alloy,and the friction coefficient is kept in a small range.The main wear mechanisms are abrasive wear and oxidation wear,and adhesive wear is secondary.With the increase of ultra-fine VC content,the wear volume of the composite coating decreases gradually,When the VC content is 10%,the wear volume of the composite coating is 2.69×10^?2m³,which is about 2/3 of that of the coating without the addition of ultrafine VC particles.This shows that the addition of ultrafine VC particles can help to improve the microstructure and wear resistance of the composite coating.