Preparation and Performance of Gradient WC Reinforced NiCrBSi Alloy Coating Based on Flexible Metallic Cloth Technique

WC-reinforced NiCrBSi alloy flexible metal cloth containing NiCrBSi alloy powder and WC alloy powder with volume ratios i of 1:1, 2:1, 5:1, 10:1 and 20:1 was prepared by the folding roller press technique. The metal cloth with i equal to 20:1 was placed on a 316L stainless steel substrate, and stacked with another layer of metal cloth with other i values, and then four gradient WC reinforced NiCrBSi alloy coatings were obtained by vacuum brazing. The distribution of WC particles in the coatings and the wear resistance and tensile properties of the coatings were studied. The results show that the gradient coatings were prepared successfully by controlling the thickness of metal cloth at 0.5 mm and brazing holding time of 10 min. The gradient slope characterizing the distribution of WC particles in coatings decreased with increasing i in the upper metal cloth. The gradient coatings improved the wear resistance of the substrate obviously. The wear resistance of the coating increased while the tensile strength decreased with increasing gradient slope. During the tensile process, multiple penetration cracks were produced in the coating with a relatively large gradient slope.