利用激光熔覆增材制造技术制备了宏观形貌良好、组织致密均匀、无气孔和裂纹的WC/Co50/Al硬质合金涂层刀具。研究结果表明, 刀具熔覆层由WC、W2C、Al2O3、Co3W3C、固溶体CoCr和(Co,Ni,Fe,Cr)2Si等物相组成; 涂层表面的硬质WC大颗粒包覆在粘接相Co50中, 部分熔化和分解的WC小颗粒形成了固溶体; 切削过程中, 轴向切削力和径向切削力相对稳定, 切向切削力波动较大; 激光熔覆硬质合金刀具产生的切向切削力和切削热均高于YG8硬质合金刀具的, 但经前者加工处理后的工件的摩擦系数和表面粗糙度均小于后者的。

The WC/Co50/Al cemented carbide coated tools with good macro morphology, uniform and dense microstructure, no pores and cracks are prepared by the laser cladding additive manufacturing technique. The study results show that the laser cladding layer of tools mainly consists of WC, W2C, Al2O3, Co3W3C, solid solution CoCr and (Co, Ni, Fe, Cr)2Si phases. The large hard WC particles on the laser cladding coating surface is coated in the Co50 bonding phase. The solid solution is formed by small WC particles with partial melting and decomposition. The axial and the radial cutting force are relatively stable in the cutting process, while the tangential cutting force fluctuates greatly. The tangential cutting force and the cutting heat of the laser-cladding cemented carbide tools are higher than those of YG8 cemented carbide cutting tools. However, the friction coefficient and the surface roughness of the work piece treated by the former are less than those by the latter.