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针对钛合金材料难以加工切削的特点,以常用钛合金TC4为对象进行了切削变形模拟及试验研究。运用有限元法,再现了钛合金切削变形过程和切屑的形成机理。模拟仿真表明,在刀尖附近的材料由于高温、高应力状态形成了软化区,切屑根部发生热塑性失稳,使切屑上部被挤裂而下部仍旧相连,呈锯齿状。快速落刀试验表明,材料于刀尖附近的变形程度和温度较高,切屑发生集中剪切滑移,呈明显锯齿状,而原纵横交错分布的网篮状组织变成了沿切削方向的条纹状,并在切屑根部扫描组织中还观察到细小的微裂纹,切屑形态与仿真结果基本相同。
Aiming at the difficult machining and cutting characteristics of titanium alloy, cutting deformation simulation and experimental research are carried out on the common titanium alloy TC4. Finite element method was used to reproduce the cutting deformation of titanium alloy and the mechanism of chip formation. The simulation results show that the material in the vicinity of the tip forms a softened zone due to the high temperature and high stress. The thermal instability of the chip root causes the upper part of the chip to be cracked and the lower part still to be connected with a jagged shape. Rapid drop test shows that the material near the tip of the deformation and high temperature, the chip concentrated shear slip, was significantly jagged, while the original criss-cross network of basket-like organization along the cutting direction of the stripes Like, and in the root of the chip scanning microstructure also observed small cracks, chip morphology and simulation results are basically the same.