应用机械冲击理论分析重型硬质合金车刀冲击断裂过程，并确立其产生冲击断裂的临界条件；采用有限元仿真的方法，分析研究重型硬质合金车刀冲击断裂产生机理及破损形式，并通过冲击试验揭示硬质合金车刀冲击断裂规律。对重型硬质合金车刀疲劳行为进行研究，通过有限元仿真分析方法，提出动态载荷下硬质合金疲劳断裂产生机制，并给出硬质合金疲劳断裂的载荷条件；通过断续切削试验，研究分析导致硬质合金刀具疲劳行为产生的本质原因，以期为预防硬质合金刀具过早出现失效提供理论支持和借鉴。

Impact fracture process of cemented carbide turning tool is analyzed by using mechanics impact theory and the critical condition is also determined when the impact fracture happened. Finite element simulation is used to analyze and research production mechanism and damage form of impact fracture of cemented carbide turning tool, and through impact experiment the impact fracture rules of cemented carbide turning tool is revealed. The fatigue behavior of cemented carbide turning tool is researched, and through finite element simulation, production mechanism of fatigue fracture of cemented carbide under dynamic load is put forward, and the load condition of fatigue fracture of cemented carbide is given. Through intermittent cutting experiment, the essential reason why cemented carbide produced fatigue behavior is analyzed. All above will provide theory support and reference to prevent cemented carbide tool from failure too early.