For the coating/substrate combination, the substrate and the coating influence each other. Different coating combinations have different effects in cutting processing. Therefore, studying the cutting characteristics of different coating combinations will help guide the design of tool coatings for machining 4340 steel. In the paper, three different composite coatings were deposited on the cermet substrate. The comprehensive cutting performances of the three coating/substrate systems were discussed. During the process of cutting 4340 steel, the wear morphology of the flank surface and the rake surface, the cutting force and temperature were recorded and analyzed. The microstructure observation, cutting performances test and mechanical properties characteristic of three CVD coating system show that the TiCN/Al₂O₃ coating has the best overall performance in the process of cutting 4340 steel. The surface morphology of the coating is related to the structural design of the coating, that is, it is related to the nucleation and growth of each coating. The surface of the coated tool not only affects the friction coefficient between the tool and the chip, but also affects the temperature distribution of the chip-tool contact interface. The simulation results show that the intermediate coating between the coating and the substrate is different, and the thermal conductivity of the entire coating/substrate system is also different, which will affect the temperature distribution during the heat transfer process. The selection of the intermediate layer of the coating is very important for the design and selection of the coating tool, especially the thickness and thermal physical properties of the coating

对于涂层/基材组合，基材和涂层彼此影响。不同的涂层组合在切削加工中具有不同的效果。因此，研究不同涂层组合的切削特性将有助于指导用于加工4340钢的工具涂层的设计。在本文中，在金属陶瓷基材上沉积了三种不同的复合涂层。讨论了三种涂层/基材系统的综合切削性能。在切削4340钢的过程中，记录并分析了侧面和前刀面的磨损形态，切削力和温度。三种CVD涂层系统的显微观察，切削性能测试和力学性能特征表明TiCN / Al ₂ O₃在切割4340钢的过程中，镀层具有最佳的整体性能。涂层的表面形态与涂层的结构设计有关，即，与每种涂层的形核和生长有关。涂覆工具的表面不仅影响工具与切屑之间的摩擦系数，而且影响切屑-工具接触界面的温度分布。仿真结果表明，涂​​层与基体之间的中间涂层不同，整个涂层/基体系统的热导率也不同，这将影响传热过程中的温度分布。涂层中间层的选择对于涂层工具的设计和选择非常重要，