难加工材料零件超低温冷却加工理论与技术

To overcome the high-quality and efficient processing problems of the key parts in high-performance equipment, it is urgent to investigate the cryogenic machining theory and technology of pivotal components made of advanced difficult-to-machine materials, such as titanium alloy and Kevlar fiber reinforced composite. In this project, the core issues are focused on the study of tool-workpiece thermal/mechanical interactions, shape and performance cooperative control of parts, and the cooling-lubrication application. Initially, service performance evolution of materials and deformation of parts under cryogenic condition are revealed. And then, the thermal/mechanical modification model of the tool-chip-workpiece zone under the condition of intensive cooling is established. Following, the cryogenic cooling-lubrication novel methods are proposed. A series of key technologies including the error compensation of deformation induced by hot-cold instantaneous effect, accuracy control of jet status, development of cutting tools with CMWF (cryogenic mental working fluid), and the function-structure integration with cryogenic coolant transporting internally in the through-spindle and through-cutter are investigated. Finally, a comprehensive experimental system for cryogenic machining is developed independently. According to the requirement of major national projects and the industry characteristics of Liaoning province, the cryogenic machining techniques for typical difficult-to-machine material parts are explored by the approach of combination between school and enterprise. Completely, this research will make a significant contribution to consummate advanced machining theory, lay the technology foundation of independent development of processing equipment, compensate for the lack of advanced equipment manufacturing technology in aerospace industry and other fields, and improve the core competitiveness of potential industry products in Liaoning province.

针对高端装备制造中亟待突破的关键零件高质高效加工难题，研究以钛合金、芳纶纤维增强复合材料为代表的先进难加工材料零件超低温冷却加工理论与技术。围绕刀具-工件热/力交互作用、零件形性协同控制、冷却与润滑协调施加等核心问题，揭示超低温冷却环境下材料使役性能与零件几何形状演化的新规律，建立强冷却下刀具-切屑-工件的热/力修正模型，提出超低温冷却润滑协调新方法，研究局部“热-冷”瞬时复合诱导的零件变形误差补偿、超低温介质射流状态精准调控、中空传输式刀具研制、超低温介质内喷式功能-结构一体化集成等关键技术，开发具有自主知识产权的超低温冷却加工综合实验系统。结合国家重大工程需求和辽宁产业特点，通过校企联合，探索典型难加工材料零件超低温冷却加工工艺。为完善先进加工理论、奠定加工装备自主研发的技术基础、补足我国航空航天等高端装备制造的技术短板、提升辽宁潜在产业产品核心竞争力做出积极贡献。

面向我国重点制造领域高端装备先进材料零件的高效高精加工需求，结合辽宁省高端装备制造发展方向，针对超低温冷却加工面临的科学问题，系统研究了以钛合金、芳纶纤维复材为代表的难加工材料零件的超低温加工基础理论与关键技术。. 在理论与技术方面，揭示了材料使役性能的超低温应激式反应规律，提出了超低温冷却可控变量对材料力学性能影响的评价方法，建立了超低温冷却加工切削区域温度场预测模型，构建了基于刀具切削区微元策略的切削力模型，提出了面向超低温加工的软质固体粉末主动润滑方法，阐明了热-冷复合诱导的零件表面温度场演化与宏观变形机理，形成了虑及多变量耦合的液氮射流状态调控方法，设计了以热/压低损为目标的刀具内液氮通道结构，发明了基于定向导引与热阻强化的超低温隔热方法，设计了多层次复合式超低温动密封结构，实现了超低温介质内喷式冷却功能-结构集成。. 在装备研制方面，开发了独立式和集成式液氮射流调控装置，研制出国内首套液氮内喷式机械主轴与刀柄，研发出系列超低温介质中空传输式车、铣、钻刀具，开发了机床操作空间监测及预警系统，研制出国内首台液氮内喷式加工机床样机CVM600，主要冷却参数包括：冷却温度-196~-20℃、射流压力0.1~0.8MPa、液氮流量0~100L/h。. 在成果应用方面，开展了TC/TA系列钛合金、芳纶纤维复材等难加工材料的超低温冷却切削试验研究。研制的液氮内喷式加工机床应用于上海航天设备制造总厂，开发的液氮射流调控装置应用于西安航天发动机有限公司，形成的超低温加工工艺规程应用于中国航发沈阳黎明航空发动机有限责任公司。. 本项目发表/录用学术论文28篇，其中SCI论文16篇；申请国家发明专利10项，已授权6项。所形成的超低温冷却加工新方法、新工艺与新装备，对完善清洁加工理论与技术、提升我国难加工材料零件加工能力、助推辽宁重大装备制造产业振兴具有重要促进作用。