The precision and efficiency of machining of aerospace thin-walled components (ATWCs) directly affect aircraft performance and reliability. This paper systematically reviews the cutting technology for ATWCs, covering advanced fixture technology, the prediction and control (or suppression) of machined surface integrity, deformation, and cutting chatter, as well as the application of digital twin (DT) technology. The section on advanced fixture technology provides a detailed analysis of the operational mode, structural features, functionality and applications of various advanced fixtures suitable for the machining of ATWCs. The surface integrity section discusses the mechanisms of surface state formation during machining of aerospace metal material parts, alongside predictions and control methods for surface integrity. The deformation section analyzes causes of machining-induced deformation in machining ATWCs and introduces relevant prediction and control methods. The cutting chatter section discussed the stability analysis techniques of cutting process and chatter suppression technology, including online monitoring and recognition, active and passive suppression technologies, and methods. The DT technology section showcases the specific application of this technology in the machining of ATWCs. The paper summarizes different aspects of these technologies, offering a comprehensive understanding and facilitating in-depth research into the machining technology of ATWCs. It can serve as a reference and guide for scholars conducting research in this field.
This focused review for the development of the thermo-stamping process and simulation is concentrated on the systemically overview of the representative publications reflecting the research progress in this area rather than a comprehensive survey of the literatures directly and indirectly related to the subjects. The key features of the global process and the local process and the corresponding simulation methods are reviewed and the merit of the publications in the context of thermo-stamping is discussed. The models on how microscopic defects are created during consolidation and many other studies are out of scope. The review will highlight the development of the thermo-stamping process and considerable progress in the simulation techniques and try to identify the gaps in the current research and the challenges to be met to achieve the goal for practical engineering application of this advanced forming method.
电子束选区熔化(SEBM)过程中,粉末颗粒在电子束作用下带负电引起库仑相互作用,易造成粉末散射,发生吹粉现象.此现象会导致电子枪放电、束流不稳定、粉末不均匀铺展等问题,继而造成工艺不稳定而加工停止.为扩大SEBM工艺适用范围,以电子束与粉末相互作用为基础,从粉末特性和工艺参数两方面分析了吹粉的形成机理及影响因素,根据降低粉末间静电力的方式总结了预防吹粉的措施,最后阐述了吹粉问题在SEBM基础研究方面的发展方向,以期为SEBM长期工作稳定性、可靠性的提高及质量提升提供参考.
钛合金空心点阵是典型的承载–功能一体化结构,采用单轴拉伸方法,在不同温度、应变速率条件下测定TA15、TA32钛合金的超塑拉伸延伸率,最大延伸率分别达到1450％和950％,后在不同温度、压力条件下进行扩散连接试验.根据超塑拉伸和扩散连接试验,确定了超塑成形和扩散连接(Superplastic forming/diffusion bonding,SPF/DB)的最佳工艺参数为:920℃/1.5～2.0 MPa/2 h,制备了不同构型和几何参数的TA15、TA32钛合金空心点阵结构件.采用平压方法和三点弯曲方法测定了钛合金空心点阵的力学性能,压缩和弯曲强度最大值分别达到23.83 MPa、596 MPa,通过有限元和试验分析的方法,研究了几何参数对钛合金空心点阵平压和弯曲性能的影响规律.采用单面加热方法,研究了钛合金空心点阵结构的隔热性能,在400℃/1 h条件下,隔热温差达到276.3～310℃.
碳纳米管具有优异的力学性能,同时还拥有高电导率、高热导率、阻燃性等功能优势,有望在航空领域多个功能方向得到广泛应用.本文根据碳纳米管面向航空领域各功能方向的应用需求,综述了碳纳米管在导电结构和电磁屏蔽、航空用复合材料结构健康监测、复合材料电加热固化、飞机机翼电热除冰和阻燃复合材料中的研究进展情况,分析了碳纳米管在各种功能应用中的优势和不足.结果表明,碳纳米管及其宏观体在各类功能应用中表现出极大的潜力,但仍需要其大尺寸、低成本制备技术,高质量稳定性控制技术等作为其功能应用的强有力支撑.
