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采用激光熔覆技术 ,在 4 5 # 钢表面进行了镍基合金粉末添加TiO2 的熔覆试验。通过对激光熔覆工艺参数及TiO2 含量的优选可以获得质量良好的熔覆层。对激光熔覆层横断面进行了显微硬度测量和显微组织分析 ,对熔覆层表面进行了X射线衍射 (XRD)物相分析及摩擦学性能测试。试验表明 ,当TiO2 含量 3wt . %～ 4wt . % ,激光功率 1 8kW ,扫描速度 2～ 4mm/s时 ,可以获得无裂纹、无气孔且与基底呈冶金结合的质量良好的熔覆层。TiO2 能够提高镍基合金熔覆层的韧性、耐磨性 ,细化熔覆层的组织 ,降低熔覆层的裂纹敏感性。TiO2 对G112镍基合金激光熔覆层的改善归因于TiO2 对熔覆层组织的均匀细化、对粗大针状脆性硬质相的抑制以及对韧性相成分的提高作用
Using laser cladding technology, cladding experiments of Ni-based alloy powder added TiO2 on 45 # steel surface were carried out. Through the laser cladding process parameters and the preferred content of TiO2 can get good quality cladding layer. The microhardness and microstructure of the laser cladding layer were measured. The surface of the cladding layer was characterized by X-ray diffraction (XRD) and tribological properties. Experiments show that when the content of TiO2 is 3wt.% ~ 4wt.%, The laser power is 18kW and the scanning speed is 2 ~ 4mm / s, a good quality cladding layer can be obtained without cracks and without pores and metallurgically bonded with the substrate. TiO2 can improve the toughness and wear resistance of the nickel-based alloy cladding layer, refine the structure of the cladding layer and reduce the crack sensitivity of the cladding layer. The improvement of the laser cladding of the G112 Ni-based alloy by TiO2 is attributed to the uniform refinement of the microstructure of the cladding layer, the inhibition of the coarse needle-shaped brittle hard phase and the improvement of the toughness phase composition