机构地区:[1]上海交通大学机械与动力工程学院,上海200240 [2]航空工业成都飞机工业(集团)有限责任公司,成都610091
出 处:《机械工程学报》2024年第9期206-217,共12页Journal of Mechanical Engineering
基 金:航空发动机及燃气轮机基础科学中心资助项目(P2022-A-IV-002-001)。
摘 要:现代航空部件对材料的耐高温性、高强度和轻量化提出了更高要求。SiC_(f)/SiC复合材料具有优异的综合性能,但其高脆性和各向异性使其高性能制造面临挑战。通过激光烧蚀预实验,掌握了Si C_(f)/Si C复合材料激光烧蚀产物的物相组成和烧蚀机理,探究了激光参数对烧蚀性质的影响规律。通过常规铣削和激光烧蚀辅助铣削的对比实验,分析了常规铣削、部分烧蚀-铣削和完全烧蚀-铣削三种不同加工策略的材料去除机理,探究了烧蚀层占比对加工表面质量的影响规律。研究表明:激光烧蚀产物主要由3C-SiC和非晶态SiO_(2)组成。常规铣削加工中,纤维发生宏观脆性断裂,已加工表面存在多处裂纹、凹坑等加工缺陷。部分烧蚀-铣削中,纤维断裂以微观脆性断裂为主,少部分位置发生了纤维拔出和宏观脆性断裂。完全烧蚀-铣削加工中,纤维发生了微观脆性断裂,基体发生鳞状破碎。激光烧蚀辅助铣削加工质量优于常规铣削,部分烧蚀-铣削和完全烧蚀-铣削的表面粗糙度基本相同。低烧蚀层占比和高烧蚀层占比下进行铣削加工切削力差距较小。低烧蚀层占比的铣削加工中,纤维以微观-宏观脆性断裂为主;高烧蚀层占比的铣削加工中,大部分纤维发生了微观脆性断裂。综上所述,部分烧蚀-铣削和低烧蚀层占比是较优的加工方案。The high temperature resistance,high strength and light weight of SiC_(f)/SiC composites are required for modern aerospace components,and SiC_(f)/SiC composites have excellent comprehensive performance,but their high brittleness and anisotropy make it a challenge for high-performance manufacturing.Through the laser ablation pre-test,the physical phase composition and ablation mechanism of laser ablation products of SiC_(f)/SiC composites are grasped,and the influence of laser parameters on the ablation properties is investigated.Through the comparison experiments of conventional milling and laser ablation-assisted milling,the material removal mechanisms of three different processing strategies,namely,conventional milling,partial ablation-milling and complete ablation-milling,are analysed,and the influence of the ablation layer ratio on the processing surface quality is investigated.It is shown that the laser ablation products are mainly composed of 3C-SiC and amorphous SiO_(2).In conventional milling,macroscopic brittle fracture of fibres occurred,and machining defects such as multiple cracks and pits existed on the machined surface.In partial ablation-milling,fibre fracture is dominated by microscopic brittle fracture,and fibre pull-out and macroscopic brittle fracture occurred at a few locations.In the full ablation-milling process,microscopic brittle fracture of fibres occurred,and scale fracture of the matrix occurred.The quality of laser ablation-assisted milling machining is superior to conventional milling,and the surface roughness was essentially the same for partial ablation-milling and complete ablation-milling.The difference in cutting force between milling with low and high ablative layer percentage is small.Micro-macro brittle fracture dominated the fibres in the milling process with low ablative layer percentage;micro-brittle fracture occurred in most of the fibres in the milling process with high ablative layer percentage.In summary,partial ablation-milling and low ablative layer ratio are the pref
关 键 词:SiC_(f)/SiC复合材料 激光辅助铣削 材料去除机理 加工质量
分 类 号:TH16[机械工程—机械制造及自动化]
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