Ni60-TiO_2-Al-B_4C-C合金激光熔覆涂层的组织及性能

以Ni60、TiO2、B4C、C、Al粉为原料,利用激光熔覆技术在45#号钢表面原位合成制备了TiC/TiB2增强的复合涂层,采用金相显微镜、扫描电镜(SEM)、X射线衍射仪(XRD)、维氏硬度计对涂层组织进行测试分析。结果表明:复合涂层内部无裂纹、气孔等缺陷,与基体呈冶金结合;其主要物相为Ni3(Al,Ti)、TiC、TiB2、(Fe,Cr)7C3和α-Fe;激光熔覆过程中原位合成的块状TiC和六边形状TiB2增强相弥散分布在复合涂层中,明显提高了熔覆层显微硬度;涂层显微硬度呈梯度分布,最大可达767Hv0.2,约为基材显微硬度的3倍。

The microstructure and property of laser cladding coating prepared by Ni60-TiO_2-Al-B_4C-C alloy

A reinforced TiC/TiB2composite coating is in-situ synthesized on the surface of 45# steel by means of laser cladding technique using Ni60,TiO2,B4C,C and Al powders as raw materials.Microstructure and property of the composite coating is measured by using metallographic microscope,scanning electron microscopy(SEM),X-ray diffraction analysis(XRD),and Vickers hardness tester.The result shows that the bonding between the composite coating and substrate of 45# steel is well metallurgical,continuous and almost defect-free.The in-situ synthesized TiC and TiB2 particulates diffusely distribute in the composite cladding.So the microhardness of the composite coating is greatly improved and is in gradient distribution with the maximum to be 767Hv0.2,which is about 3 times larger than that of the steel substrate.