The new material, compacted graphite iron, plays a key role in the reliability of engine and the realization of high emission standard, but it is a difficult-to-machine material. In high-speed milling process of compacted graphite iron, thermal crack induced by thermal stress is the main reason for tool breakage and chipping. In order to reveal the initiation and propagation mechanisms of thermal cracks, and improve tool life by controlling the formation of thermal crack, it is necessary to study the three-dimensional transient cutting tool temperature field under the condition of periodic heat transfer in intermittent cutting. In this paper, the three-dimensional transient FEM cutting tool temperature field model for high-speed milling of compacted graphite iron was established by using the heat source method. The uneven spatial distribution of the heat flux on the rake face of the tool, and the changes of heat flux density due to the transient cutting thickness and tool-chip contact length over time were considered, and the influence of boundary conditions in the cutting stage and the non-cutting stage were also all taken into account. The heat flux action time and the ratio of cutting time and non-cutting time in the model were set according to the experimental conditions of actual milling process. The established three-dimensional transient cutting tool temperature field model was finally verified by measuring the real temperature in high-speed orthogonal turning experiment. The results showed that the predicted value of the model was consistent with the experimental value, and the predicted error was less than 6.0%, indicating that the model has high accuracy for simulation. This model has great theoretical significance for the development of new tool materials for compacted graphite iron processing, studying the mechanism of thermal crack, controlling and preventing tool failure caused by thermal crack.

新型材料蠕墨铸铁对发动机的可靠性和高排放标准的实现起着关键作用，但它是一种难加工材料。在蠕墨铸铁高速铣削过程中，热应力引起的热裂纹是造成刀具断裂和崩刃的主要原因。为了揭示热裂纹的产生和扩展机制，通过控制热裂纹的形成来提高刀具寿命，有必要研究断续切削中周期性传热条件下的三维瞬态刀具温度场。本文采用热源法建立了用于蠕墨铸铁高速铣削的三维瞬态有限元刀具温度场模型。考虑了刀具前刀面热流密度的空间分布不均匀，以及瞬态切削厚度和刀切接触长度引起的热流密度随时间的变化，以及切削阶段边界条件的影响非切削阶段也都考虑在内。根据实际铣削过程的实验条件设置模型中的热流作用时间和切削时间与非切削时间的比值。最终通过高速正交车削实验测量真实温度对建立的三维瞬态刀具温度场模型进行验证。结果表明，模型预测值与实验值一致，预测误差小于6.0%，表明该模型具有较高的仿真精度。该模型对于开发用于蠕墨铸铁加工的新型刀具材料，研究热裂纹产生的机理，控制和预防热裂纹引起的刀具失效具有重要的理论意义。