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采用超音速火焰喷涂工艺在20CrMo钢圆片上成功制备25%NiCr-Cr3C2金属陶瓷涂层,研究了不同燃料对喷涂层组织性能的影响。结果表明,以丙烷为主要燃料所得喷涂层的组织不均匀,存在典型的层状结构,孔隙率约为3.2%,显微硬度仅为836 HV,涂层断裂韧性KIC为2.08 MPa.m3/2;以煤油为主要燃料所得喷涂层的组织分布均匀,细小致密,孔隙率约为2.4%,显微硬度可达1045 HV,涂层断裂韧性KIC为2.56 MPa.m3/2。前者的组成相为Ni(Cr)固溶体、Cr3C2和微量NiCrO4;后者的组成相除Ni(Cr)固溶体和Cr3C2外,还有Cr7C3、Cr23C6和Ni(Cr)相出现。
A 25% NiCr-Cr3C2 cermet coating was successfully prepared on a 20CrMo steel by supersonic flame spraying. The effects of different fuels on the microstructure and properties of the sprayed coating were studied. The results show that the microstructure of the sprayed coatings with propane as the main fuel is inhomogeneous and has a typical lamellar structure with a porosity of about 3.2%, a microhardness of 836 HV and a fracture toughness KIC of 2.08 MPa.m3 / 2 The kerosene-based spray coating has a uniform and compact structure with a porosity of about 2.4%, a microhardness of 1045 HV and a coating fracture toughness KIC of 2.56 MPa.m3 / 2. The former is composed of Ni (Cr) solid solution, Cr3C2 and trace NiCrO4; the latter is composed of Cr7C3, Cr23C6 and Ni (Cr) phases in addition to Ni (Cr) solid solution and Cr3C2.