激光熔覆Mo2Ni3Si／NiSi金属硅化物复合材料涂层组织与耐磨性

以39Mo-35Ni-26Si(w％)合金粉末为原料，采用激光熔覆技术，在1Cr18Ni9Ti不锈钢基材表面翩得以Mo2Ni3Si金属硅化物为初生相，以Mo2Ni3Si／NiSi共晶相为基体的金属硅化物耐磨复合材料涂层。涂层的常温干滑动磨损试验结果表明，在磨损过程中，Mo2Ni3Si／NiSi共晶相轻微地优先磨损，Mo2Ni3Si金属硅化物微微凸出于磨损表面，起到抗磨的骨干作用。由于Mo2Ni3Si金属硅化物具有很高的硬度和很强的原子间键合力，在磨损过程中难于变形和粘着，激光熔覆Mo2Ni3Si／NiSi金属硅化物复合材料涂层具有优异的耐磨性，与1Cr18Ni9Ti标样相比，涂层的耐磨性提高了56倍。

Microstructure and Wear Properties of Laser Clad Mo2Ni3Si/NiSi Metal Silicide Composite Coatings

Mo2Ni3Si/NiSi wear-resistant metal silicide composite coatings were fabricated by laser cladding with 39Mo-35Ni-26Si(wt% ) powder as precursor on the substrate of austenitic stainless steel 1Crl8Ni9Ti. The Mo2Ni3Si/NiSi composite coatings have a fine microstructure consisting of MojNisSi primary metal silicide dendrites and the interdendritic Mo2Ni3Si/NiSi eutectic structure. The dry sliding wear test indicates that the slight preferential wear of the Mo2Ni3Si/NiSi eutectic structure occurs during the dry sliding wear process, resulting in the slight protrusion of Mo2Ni3Si metal silicide reinforced phase. Due to the high hardness and strong covalent atomic bonding of Mo2Ni3Si metal silicide, no deformation and adhesion transfer were observed on the worn surface. Laser clad Mo2Ni3Si/NiSi metal silicide composite coating has an excellent wear resistance under the dry sliding wear test condition. Wear resistance of the composite coating is up to 56 times higher than that of the austenitic stainless steel 1Crl8Ni9Ti.