汽雾冷却下微织构刀具切削镍基高温合金摩擦特性研究

With its good mechanical properties and chemical stability, nickel-based superalloy GH4169 is widely used in rocket and aeronautic motor manufacturing. But its hardness leads to poor cutting performance such as high cutting temperature and cutting force, the tendency of work hardening and short tool-life, which decreases dimensional accuracy and surface integrity..Aiming at the problems of high cutting temperature and serious tool wear during the machining process of large high temperature alloy parts, the research on the micro textured tool cutting high temperature alloy was carried out. The research started with the selection of the parameters of the low temperature cooling system. In order to achieve the best parameters of low temperature spray cooling system, an experiment of turning high temperature alloy GH4169 was performed under the optimum cooling and lubrication parameters; then the design and optimization model of micro textured tool was established.Through the simulation analysis and experiment, the reasonable shape and structure parameters of the cutting tool are optimized,which laid a firm foundation in the optimization of cutting process and surface quality control for further study of high temperature alloy cutting with spray-cooling.Based on the study findings, a finite element simulation model of tool wear was established, and wear mechanism and thermal effect mechanism of tool micro textures in spray cooling was analysed.Finally,the integrity of machined surface was put into system analysis,and high temperature alloy cutting was achieved with the optimal cutting parameters.

航空发动机、燃气轮机的涡轮部分轮盘普遍采用镍基高温合金材料，高温合金材料具有良好的高温机械力学性能和化学稳定性，但因其强度高，切削性能差，在加工过程中出现切削温度高、切削力大、刀具磨损严重等情况。本课题针对大型高温合金件加工过程中出现切削温度高、刀具磨损严重等问题，对汽雾冷却下微织构刀具切削高温合金进行研究。首先从低温冷却润滑系统参数的选择入手，在最优冷却润滑参数下进行切削高温合金GH4169 实验以选出最佳的低温汽雾冷却系统参数；其次建立微织构刀具的设计及优化模型，通过仿真分析及实验确定刀具合理的微织构形状及结构参数，为进一步研究汽雾冷却下切削高温合金切削过程优化及加工表面质量控制奠定基础。最后，建立切削过程有限元仿真模型，研究汽雾冷却条件下刀具微织构的磨损机理及热效应机理并对已加工表面完整性做系统分析，确定合理的切削参数实现高温合金的高效切削。

镍基高温合金GH4169属于难加工材料，其本身塑性较大，加工硬化严重、切削力和切削温度较高，切削过程刀具的磨损严重，甚至在切削的早期和后期出现刀具破损的现象。项目设计并加工出不同形貌、参数的微织构刀具，使用Deform和Abaqus软件建立符合实际切削情况的微织构刀具切削GH4169的三维仿真模型；通过汽雾冷却条件下的仿真分析和实验进行对比研究。研究得出了不同汽雾参数下切削力、切削温度的变化规律，微织构参数和汽雾参数对刀片磨损机理的作用效果及作用规律以及工件表面完整性参数的变化规律。研究成果为后续其他材料的微织构刀具的设计开发提供理论依据，微织构刀片既能高效切削GH4169，又能提高刀具寿命，有工程应用价值。