Experimental Study On Cryogenic Milling Of Aramid Fiber Composite

Aramid fiber composites have series properties such as as light weight, high specific strength and electromagnetic penetration and excellent impact resistance, which have been widely used in the fields of aerospace and armor protection and weaponry. Machining is a necessary process of composite component to meet the requirements and assembly connections dimensional accuracy after molding. However, owing to the complicated nohomogeneity and anisotropy and high toughness, processing defects are early produced in traditional machining, which result composites being the representative difficult-to-cut materials. So processing technology of high quality low damage becomes a hot research topic due.In this paper processing mechanism and defects of aramid fiber composite was analyzed. Based on cryogenic properties of aramid fiber composite, Milling quality was studied with liquid nitrogen cryogenic cooling by build cryogenic milling experimental platform. Machining experiments of milling force and milling quality were conducted by diamond cutting tools. In this paper the main contents contains the following.(1) According to machining defects of aramid fiber composites, in the cutting process the thermal influence to material properties was revealed. cutting mechanism was analyzed through researching cryogenic properties of aramid fiber and resin matrix and measuring cutting temperature and fiber failure model.(2) According processing experiment requirements of aramid fiber composite materials, cryogenic milling platform was built with liquid nitrogen control system and inside cooling tool holder. For different processing requirements outside the spray and inside spray system were designed. Liquid nitrogen flow and temperature in different target distance.(3) cryogenic milling force experiments were carried out to compare variation of cutting force under liquid nitrogen cooling and without cooling by Single factor analysis. Milling force could be reduced by cryogenic cooling. Cryogenic milling process technology was researched and optimized preliminarily.(4) By comparing milling quality of aramid fiber composites under different cooling conditions, cryogenic machining was proved to improve milling quality, and the machined surface morphology at different cooling temperatures was analyzed to study the effects of cooling temperature and machining parameters on machining quality. Liquid Nitrogen Cooling can effectively improve the aramid fiber composite machining quality, and reduce processing defects. A feasible approach is provided for aramid fiber composite machining with high quality and low damage.