钢结硬质合金GT35切削去除机理研究

为研究金刚石磨粒刀具切削钢结硬质合金GT35的微观刻划过程与材料去除机理，以单颗粒金刚石刻划实验为研究手段，分析其微观切削力的影响因素及材料的微观去除过程。通过单颗粒金刚石变切深实验发现，切削力与切痕截面积之间呈线性关系，获得的线性比例系数k的估计值可通过单颗粒金刚石等切深实验修正。随后，通过扫描电镜对GT35材料表面切痕形貌进行观测，并用激光共聚焦显微镜对其形貌进行三维建模，研究不同刻划深度下的材料去除模式。结果表明:修正后k(F_x)为0.026 29 N/μm2（R₁=0.990 46），k(F_z)为0.046 42 N/μm2（R₂=0.994 08）； 调质GT35材料在多种切深下均以塑性去除为主，其中切痕底面呈现明显塑性剪切去除状态，切痕边缘位置呈现一定的脆性断裂状态。刀具在切削过程中会在刀尖处形成材料堆叠死区，引起刀具崩刃及磨损，且切痕表面形貌的形成与刀具磨损密切相关。 

Study on removal mechanism of steel bonded cemented carbide material GT35 in cutting process

Single particle diamond cutting experiments are designed to research the micro scratching process and material removal mechanism of GT35 steel bonded cemented carbide. The value of linear scale coefficient k is estimated as well. The exact value of k is further confirmed by equal depth cutting experiment. Furthermore, the material removal approaches at different cutting depths are discussed by microscopic observation and three-dimensional morphology modeling by SEM and laser confocal microscope. It is observed that there is a linear functional relationship between cutting force and groove cross-sectional area. k (F_x) is 0.026 29 N/μm2(R₂=0.990 46) and k (F_z) is 0.046 42 N/μm2(R₂=0.994 08) after fitting. The quenched and tempered GT35 material is mainly plastic removal under various cutting depths, in which the bottom surface of the groove shows an obvious plastic shear removal state, and the edge shows a certain brittle removal state. During the cutting process, there will form a material stacking dead zone at the tool tip, causing tool edge collapse and wear. The formation of the surface morphology is closely related to tool wear.