高温合金蜂窝芯高速铣削材料去除机理与损伤行为

高温合金蜂窝芯材料具有高比刚度、轻质和能量吸收特性好等优异性能，被视为下一代高超声速飞行器热防护结构极具潜力的材料。高速铣削是高温合金蜂窝芯零件成型过程中重要的减材制造工艺，在蜂窝芯材料高速铣削时，蜂窝芯材料面内刚度低且高温合金塑性好，较小的切削力就会使蜂窝壁产生较大的塑性变形，导致蜂窝芯加工精度较低、加工损伤难以控制，对后续焊接、装配等工序产生不利影响。基于有限元仿真对蜂窝壁切削材料去除机理进行了深入研究，探索了铣削参数、刀具类型和铣削方式对铣削过程中铣削力和加工损伤的影响。研究结果表明，蜂窝壁切入角是影响蜂窝芯材料切削加工过程中瞬时应力分布和成屑机理的关键性因素。得到了铣削参数、刀具类型和铣削方式对高温合金蜂窝芯加工过程中加工损伤的影响规律。对于铣削参数，过大的进给量会导致芯格变形等加工损伤，降低切削速度会提高微小毛刺等加工损伤发生的频率；本文采用的三种刀具的对比结果表明，立式铣刀加工质量最好。插铣方式会产生明显的轴向冲击，而侧铣方式可以有效避免轴向冲击。研究成果为高温合金蜂窝芯低损伤高性能加工提供了理论依据和工艺技术储备。

Material Removal Mechanism and Damage Behavior in High-speed Milling of High-temperature Alloy Honeycomb Core

Superalloy honeycomb core material has excellent properties such as high specific stiffness, light weight and good energy absorption characteristics. It is regarded as a potential material for the thermal protection structure of the next generation hypersonic vehicle. High speed milling is an important material reduction manufacturing process in the forming process of Superalloy honeycomb core parts. During high-speed milling of honeycomb core materials, the in-plane stiffness of honeycomb core materials is low and the plasticity of superalloy is good. Small cutting force will produce large plastic deformation of honeycomb wall, resulting in low machining accuracy of honeycomb core and difficult to control machining damage, which will have an adverse impact on subsequent welding, assembly and other processes. Based on the finite element simulation, the material removal mechanism of honeycomb wall cutting is deeply studied, and the effects of milling parameters, tool types and milling methods on milling force and machining damage in the milling process are explored. The results show that the cutting angle of honeycomb wall is the key factor affecting the instantaneous stress distribution and chip forming mechanism in the cutting process of honeycomb core material. For milling parameters, excessive feed rate will lead to machining damage such as core lattice deformation, and reducing the cutting speed will increase the frequency of machining damage such as micro burr; The comparison results of three kinds of cutting tools used here show that the machining quality of vertical milling cutter is the best. Insert Milling will produce obvious axial impact, side milling can effectively avoid axial impact.The effects of milling parameters, tool types and milling methods on machining damage of Superalloy honeycomb core are obtained. The research results provide a theoretical basis and process technology reserve for low damage and high-performance machining of Superalloy honeycomb core.