This study addresses the finished surface quality of cemented tungsten carbide obtained via direct cutting with a diamond-coated carbide end mill under ultrasmall feed rates. The surface appearance, composition distribution, profile, roughness, residual stress, and transverse rupture strength were experimentally investigated. The finished surfaces obtained via electric discharge machining with two types of machining conditions and mechanical polishing processes were also evaluated to compare the surface quality. Two types of cemented tungsten carbide materials, TAS VC-70 and VM-40, were applied as the workpiece materials. A mirror surface can be obtained via direct cutting and mechanical polishing with both materials. The microstructure morphologies of the finished surface obtained via direct cutting were different from those obtained via mechanical polishing. In the case of VC-70 which has larger tungsten carbide grain size and higher cobalt content, the flat cross-section of the tungsten carbide grain under ductile mode cutting was conspicuous in direct cutting under small feed rate and depth of cut. In contrast, an extremely thin layer composed of fine grains of tungsten carbide and cobalt was observed on the finished surface in direct cutting under comparatively large feed rate and depth of cut. The surface roughness and profile of the finished surface resulting from direct cutting were comparatively rougher than those resulting from mechanical polishing, although the finished surface was significantly smoother than that resulting from electric discharge machining. The residual stress of the subsurface obtained via direct cutting showed larger compressive stress than that obtained via electric discharge machining and mechanical polishing under all cutting conditions and materials. Moreover, satisfactory transverse rupture strength can be obtained via direct cutting in both materials compared with other processes, and two times more transverse rupture strength can be achieved via direct cutting compared with the case of electric discharge machining in VM-40 cutting.

这项研究的重点是在超小进给速率下，通过用金刚石涂层硬质合金立铣刀直接切割获得的硬质合金碳化钨的最终表面质量。实验研究了表面外观，成分分布，轮廓，粗糙度，残余应力和横向断裂强度。还评估了在两种加工条件和机械抛光工艺下通过放电加工获得的精加工表面，以比较表面质量。两种类型的硬质合金碳化钨材料，TAS VC-70和VM-40，被用作工件材料。可以通过直接切割和机械抛光两种材料来获得镜面。通过直接切割获得的精加工表面的微观结构形态与通过机械抛光获得的微观结构形态不同。在具有更大碳化钨晶粒尺寸和更高钴含量的VC-70的情况下，在小进给速率和切削深度下的直接切削中，在延性模式切削下的碳化钨晶粒的横截面很明显。相反，在较大的进给速度和切削深度下，在直接切削的精加工表面上观察到了由碳化钨和钴的细晶粒组成的极薄层。直接切割产生的最终表面的表面粗糙度和轮廓要比机械抛光产生的表面粗糙度和粗糙度要大一些，尽管精加工表面比电火花加工表面光滑得多。在所有切削条件和材料下，通过直接切割获得的表面残余应力均比通过放电加工和机械抛光获得的残余应力更大。而且，与其他方法相比，通过两种材料的直接切削均可获得令人满意的横向断裂强度，并且与VM-40切削中的电火花加工相比，通过直接切削可获得的横向断裂强度是其两倍。