论文部分内容阅读
借助激光熔覆方法在H13钢基材上制备不同WC含量的Ni基WC复合熔覆层,采用扫描电子显微镜(SEM)、微区X射线能谱(EDS)和X射线衍射仪(XRD)分析了熔覆层表面的物相、熔覆层与基材的结合情况、熔覆层内部增强相的形貌、成分与分布;在室温下测试显微硬度、摩擦因数和磨损率。结果表明:基体和熔覆层之间为冶金结合,熔覆层物相为γ-Ni相、WC、Cr23C6、W2C相,这些碳化物呈现近圆形;激光熔覆层中Ni基体的显微硬度为550-700 HV0.1,硬质相颗粒的显微硬度为2700~3500 HV0.1,是基材显微硬度的5~7倍;Ni基+30%WC熔覆层的摩擦因数为0.7,磨损率为1.92×10~(-8)mm~3/(N·m)。随着WC含量增多45%,耐磨性进一步提高、摩擦因数约为0.4,磨损率为8.32×10~(-9)mm~3/(N·m),WC含量达到60%,摩擦因数为0.5、磨损率与45%WC熔覆层磨损率接近;综合比较,45%WC激光溶层耐磨减摩效果最佳。
The Ni-based WC composite cladding layers with different WC contents were prepared on H13 steel substrate by laser cladding method. The microstructure of the coatings were characterized by SEM, EDS and XRD The phase of the cladding surface, the combination of the cladding layer and the substrate, the morphology, composition and distribution of the phase in the cladding layer were enhanced. The microhardness, friction coefficient and wear rate were tested at room temperature. The results show that the matrix and the cladding are metallurgically bonded, the cladding phase is γ-Ni phase, WC, Cr23C6 and W2C phases, and these carbides appear nearly circular. The microstructure of the Ni matrix in the laser cladding layer Hardness of 550-700 HV0.1, hard phase particles microhardness of 2700 ~ 3500 HV0.1, is the substrate hardness of 5 to 7 times; Ni-based + 30% WC cladding friction coefficient 0.7, the wear rate is 1.92 × 10 ~ (-8) mm ~ 3 / (N · m). With the content of WC increasing 45%, the wear resistance is further improved, the friction coefficient is about 0.4, the wear rate is 8.32 × 10 -9 mm 3 / (N · m), the content of WC reaches 60% and the friction coefficient is 0.5. The wear rate is similar to that of 45% WC cladding. The wear resistance and friction reduction of 45% WC laser cladding are the best.