等离子喷涂与激光重熔复合制备Mo_(2)NiB_(2)涂层的组织和性能研究

Study on Microstructure and Properties of Mo_(2)NiB_(2)Coating Prepared by Plasma Spraying and Laser Remelting

采用大气等离子喷涂方法在Q235低碳钢表面制备Mo_(2)NiB_(2)基金属陶瓷涂层,选取300 W和500 W功率对其进行激光重熔。结果表明,激光重熔可以显著减少涂层的缺陷,使组织结构变得更加致密,界面处的弱机械结合转变为良好的冶金结合。随着激光功率的提高,涂层的结合强度和耐腐蚀性能提高,最大结合强度为38.08 MPa,最小腐蚀电流为0.033μA/cm^(2),但硬度和耐磨性降低,最小硬度为1781HV0.2,最大体积摩擦率为6.25×10^(-5)mm^(3)/(N·m)。上述等离子喷涂及2种激光重熔的Mo_(2)NiB_(2)基金属陶瓷涂层的硬度、结合强度、耐磨性和耐腐蚀性都明显高于Q235低碳钢基体。

Mo_(2)NiB_(2)based cermet coating was prepared on the surface of Q235 low carbon steel by atmospheric plasma spraying,and laser remelting was carried out at 300 W and 500 W power.The results show that the laser remelting method can significantly reduce the defects of the coating,make the microstructure more dense,and the weak mechanical bonding at the interface is transformed into a good metallurgical bonding.With the increase of laser power,the bonding strength and corrosion resistance of the coating are improved,the maximum bonding strength is 38.08 MPa,and the minimum corrosion current is 0.033μA/cm^(2);But the hardness and wear resistance are reduced,the minimum hardness is 1781HV0.2,and the maximum volume friction rate is 6.25×10^(-5)mm^(3)/(N·m).The hardness,bonding strength,wear resistance and corrosion resistance of the above plasma sprayed and two kinds of laser remelted Mo_(2)NiB_(2)based cermet coatings were significantly higher than those of Q235 low carbon steel substrate.