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用包覆法制备W-5%Re复合喷涂粉末,再采用气氛保护等离子喷涂成形技术结合真空烧结技术制备内径为8 mm、壁厚16.5 mm、长30 mm的某实验型固体火箭发动机W/Re复合喷管,并测试了喷管在地面点火试车条件下的抗热震烧蚀性能。研究结果表明,气氛保护等离子喷涂成形W/Re喷管为典型的柱状晶层片结构,致密度仅为87.5%。经2 300℃真空烧结480 min后,W/Re合金喷管由层片结构转化为颗粒状结构,致密度提高至98.6%,综合力学性能显著提高。地面试车实验后,W/Re合金喷管整体结构完好,未出现炸裂和破碎现象,抗冲刷和耐烧蚀性能良好,其线烧蚀率仅为0.15 mm/20 s。经SEM、EDS等检测发现,喉部以机械剥蚀为主、熔化烧蚀及热化学烧蚀为辅,其烧蚀程度最为严重;收敛段为机械剥蚀和热化学烧蚀,其烧蚀程度次之;而扩散段则主要发生热化学烧蚀,其烧蚀程度最低。
The W-Re composite spray powder was prepared by the coating method, and then an experimental solid rocket motor W / Re with an inner diameter of 8 mm, a wall thickness of 16.5 mm and a length of 30 mm was prepared by atmosphere protection plasma spray forming technique and vacuum sintering technique Composite nozzle, and tested the nozzle in the ground ignition test conditions of thermal shock ablation performance. The results show that the atmosphere protection plasma spray forming W / Re nozzle is a typical columnar crystal structure, the density is only 87.5%. After vacuum sintering at 2 300 ℃ for 480 min, the W / Re alloy nozzle was transformed into a granular structure from lamellar structure, the density increased to 98.6%, and the comprehensive mechanical properties were significantly improved. After the ground test, the overall structure of the W / Re alloy nozzle was intact, without the phenomenon of burst and crushing. The anti-erosion and ablation resistance was good, and the wire ablation rate was only 0.15 mm / 20 s. The SEM, EDS and other tests found that the main part of the larynx was mechanical ablation, followed by fusion ablation and thermochemical ablation, and the ablation degree was the most serious. The convergence section was mechanical ablation and thermochemical ablation, and the degree of ablation ; While the diffusion section is the main thermal chemical ablation, the lowest extent of its ablation.