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利用3 kW高功率半导体激光器,在304钢基体上制备不同含量Ni基Ni包B_4C复合陶瓷涂层,分别用扫描电镜(SEM)、X射线衍射(XRD)、显微硬度计及摩擦磨损试验机对熔覆层的显微组织、物相、硬度及耐磨性进行研究。结果表明:熔覆层主要由γ-Ni固溶体、B_4C、Fe_3B、Ni_4B_3、Cr_5B_3、CrB、Cr_3C_2、Cr_2Ni_3等物相组成;熔覆层底部晶粒以近似垂直于基体界面的细小树枝晶的形态生长的,中部以一定方向柱状晶和树枝晶存在,上部是杂乱无章的等轴枝晶;Ni包B_4C含量为40%时,熔覆层组织均匀致密、晶粒细小,与基体冶金结合,显微硬度最高1261 HV,是基体的5.7倍,耐磨性也相对较好,是基体的12倍。
The Ni-based Ni-coated B4C composite ceramic coatings with different Ni content were prepared on a 304 steel substrate by using a 3 kW high power semiconductor laser. The coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester and friction and wear tester The microstructure, phase, hardness and wear resistance of the cladding were studied. The results show that the coating mainly consists of γ-Ni solid solution, B_4C, Fe_3B, Ni_4B_3, Cr_5B_3, CrB, Cr_3C_2, Cr_2Ni_3 and other phases; the bottom of the cladding layer grows in the form of fine dendrites near the interface , While the middle part is dominated by columnar and dendrites in certain directions. The upper part is disorganized equiaxed dendrites. The microstructure of the cladding is uniform and compact, the grains are small, the microstructure is micro-hardness when the content of Ni-B 4 C is 40% Up to 1261 HV, is 5.7 times the matrix, wear resistance is relatively good, is 12 times the matrix.