摘要:
采用激光熔覆技术在H13热作模具钢表面分别制备了Co50合金涂层和TiC/Co基复合涂层.借助XRD,SEM与显微硬度计对比分析了涂层与基材的结合状态、涂层物相组成、截面组织形貌和显微硬度分布.结果表明,Co50合金涂层和TiC/Co基复合涂层均与H13钢基材呈良好冶金结合特征.Co50合金涂层主要由初生γ-Co枝晶及其间的共晶组织组成,而TiC/Co基复合涂层主要由TiC颗粒、枝晶及细小的共晶组织组成,其组成相除含有TiC,TiCo3和Cr2Ni3外,还有Cr-Ni-Fe-C等相.涂层截面显微硬度分布表明,TiC/Co基复合涂层截面平均显微硬度明显高于Co50合金涂层,分别为5520 MPa和4990 MPa,分别是H13钢基材的2.7和2.4倍.
Abstract:
TiC/Co composite coating and Co50 alloy coating were prepared by laser cladding of on the AISI H13 hot work tool steel surface.The bonding characteristics,phase constitution, microstructure and micro-hardness distribution of the coatings were analyzed and tested by XRD,SEM and micro-hardness tester.The results indicate that Co50 alloy coating as well as TiC/Co composite coating show good metallurgical bonding with the H13 steel substrate surface.Co50 alloy coating was mainly composed of γ-Co dendrite and eutectic between γ-Co dendrites, while TiC/Co composite coating which contained TiC particles, dendrite and fine eutectic,was consisted of TiC,TiCo3,Cr2Ni3 as well as Cr-Ni-Fe-C,and so on.The average micro-hardness of cross-section of TiC/Co-based composite coating and Co50 alloy coating are 5520 MPa and 4990 MPa,about 2.7 times and 2.4 times higher than that of the H13 steel substrate.
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