激光熔覆特定材料涂层的微观组织和硬度特性

摘要

镍铬碳化铬涂层坚硬致密，是非常理想的耐磨涂层。为了制备硬度较高的耐磨涂层，分别以 Ni45和 Ni60为过渡层，利用激光熔覆技术，在45钢基体上熔覆了25NiCr-75Cr3 C2涂层。采用电子探针显微分析仪（EPMA）和其配备的能谱仪（EDS）对涂层的微观组织和微区成分进行了分析，并利用显微硬度仪进行了显微硬度的测试。结果表明：以镍基合金为过渡层，在45钢基体上熔覆25NiCr-75Cr3 C2涂层，可以得到与基体结合紧密的涂层组织，且涂层硬度明显高于基体硬度；与过渡层 Ni45相比，以 Ni60为过渡层时，25NiCr-75Cr3 C2涂层的硬度更高；不同过渡层上熔覆的25NiCr-75Cr3 C2涂层微观组织结构及元素成分也不相同。%NiCr-Cr3 C2 is an ideal wear resistant coating due to its hard and compact characteristics.With the transition layers of Ni45 and Ni60 respectively,25NiCr-75Cr3 C2 is coated on the 45 steel substrate by laser cladding technology to prepare great hard wear resistant coatings.The micro structure and components of the coatings are observed and an-alyzed respectively through electron probe micro analyzer (EPMA)and energy dispersive spectrometer (EDS).And the micro hardness is measured.Test results show that the 25NiCr-75Cr3 C2 coating has good metallurgical bonding with the substrate with transition layer of nickel based alloy;the hardness of the coatings is significantly higher than that of the substrate.Compared with Ni45 /25NiCr-75Cr3 C2 coating,the Ni60 /25NiCr-75Cr3 C2 coating has higher hardness;with different transition layers,the micro structure and components of 25NiCr-75Cr3 C2 coatings are different.