基于粘弹性磨料流的高性能零件异形内曲面精准高效创成原理

Aero-engine blisk and impeller, as one kind of typical high performance parts, are of particular characteristics such as inner curved surfaces,variable cross-section,low-stiffness,strong geometry interference,and higher machining surface integrity, which make the precision machining more difficulty. In the proposal a high precision and efficiency process method based on the viscoelastic abrasive flow process principle is proposed to finish the inner curved surfaces. There are three key scientific problems to be researched. They are interface mechanics behavior of abrasive media in complex channels, high precision and efficiency process principle of inner curved surface based on abrasive flow machining and the influence of process parameters on the machined surface integrity. The main works will focus on the establishment of flow field model of abrasive media in complex channels, simulation and analysis of the flowing state of the abrasive flow media in the complex channel, force transfer mechanism of the abrasive media and the material removal mechanism, high precision machining methods of inner curved surface based on reverse modeling and design of mould core, influence rules of surface condition on abrasive flow process,etc. The new approach to process the inner curved surfaces of aero-engine blisk and impeller chould be developed by means of the study, which may be widely used and is of vital academic significance.

面向航空发动机整体叶盘、叶轮为代表的高性能零件，针对其叶栅异形曲面、变截面复杂流道、低刚度和强几何干涉等结构特点，以及数控铣削加工后的精准形面要求进一步降低粗糙度和提高表面完整性所面临的难题与挑战，提出基于粘弹性磨料流的异形内曲面精准高效加工新原理，围绕复杂流道粘弹性介质流场及其作用界面力学行为、基于模芯反求的磨料流异形内曲面高效精准创成原理及其加工过程对表层性态作用规律关键科学和技术难题，开展复杂流道的粘弹性介质流场建模和流态演变规律仿真分析、磨料流介质力传递机制和材料去除机理、基于流道模芯型面反求建模与设计的异形曲面精准形面创成方法、磨料流加工对表层性态改善的作用及影响规律、模具流道型面磨损对加工质量影响、典型试件加工验证等研究，探索航空发动机整体叶盘类高性能零件异形内曲面精确高效加工新途径。研究工作对于显著提高我国航空和石化领域重大工程关键装备高性能零件异形内曲面加工质量和使役寿命具有重要的应用价值和学术意义。

面向航空发动机整体叶盘、叶轮为代表的高性能零件，针对其叶栅异形曲面、变截面复杂流道、低刚度和强几何干涉等结构特点，以及数控铣削加工后的精准形面要求进一步降低粗糙度和提高表面完整性所面临的难题与挑战，开展了磨料流的异形内曲面精准高效加工研究。.基于剪切速率扫描、频率扫描等流变学实验建立了磨料介质的流变学表征，在此基础上构建了适用于磨料介质的非牛顿粘性本构模型，建立应力和剪切速率间的关联关系。结合非牛顿流体基本理论和所构建的磨料介质非牛顿粘性本构方程，建立了磨料介质挤压流场仿真分析模型，利用搭建的磨料流加工表面近壁区压力测试平台，对比研究了仿真分析的流体压力和实测压力的对应关系，验证了该模型对磨料流加工约束流道内的流场分布预测的准确性。建立了磨粒群在流场约束下的挤压磨料流加工材料去除分布函数模型，提出了磨料流加工全表面形貌预测的简化算式，并阐明了磨料流加工工艺参数对边缘效应的影响规律。提出了基于模具约束形面和引流段结构分区调控来削减异形内曲面边缘效应的策略，建立了全表面挤压磨料流均匀化加工的调控方法，边缘和中心抛光纹理一致，揭示了挤压磨料流加工工艺参数对零件表面粗糙度、显微硬度等的影响规律。