SiCp/Al复合材料搅拌摩擦连接-铣削复合加工机理研究

With the development of our aerospace technology, the traditional joining technology can not yet meet the needs of manufacturing the scheme structure parts for advanced rocket engines made of SiC particle reinforced aluminum matrix composites (SiCp/Al), meanwhile much attention has been paid to an advanced joining technology called Friction Stir Joining (FSJ). However, the joining integrity and the after milling efficiency when FSJ is used for SiCp/Al joining are still unsolved neck problems. In this study, it is proposed to integrate FSJ and milling process, that is, the joining and the milling can be completed at the same time, so that not only the processing efficiency but also the quality can be improved greatly. Based on this new ideal, the research work will be carried out on the heat source modeling and temperature distribution, the design and manufacture of the integrated tool, the processing mechanism and the failure mechanism of the work processed by the new integrated processing method proposed. Through the research, such scientific questions will be made clear as the energy transfer mechanism in the processing area, the performance variation of the integrated tool and the failure mechanism of the work processed, so that it is possible to provide a theoretical foundation to the optimization of the integrated processing of FSJ-milling for SiCp/Al composites, furthermore to provide technical support to the manufacture of the advanced rocket engines made of SiCp/Al composites.

随着我国航天技术的发展，传统的连接技术已不能满足火箭发动机颗粒增强铝基复合材料（SiCp/Al）主承力构件的研制与生产需要，先进的搅拌摩擦连接（FSJ）技术正受到广泛关注。但SiCp/Al的FSJ连接完整性以及后续铣削加工效率仍是亟需解决的瓶颈问题。本项目提出FSJ-铣削复合加工创新思路，在连接的同时完成铣削加工，显著提高加工效率与质量。针对这一新工艺，本项目拟分别开展FSJ-铣削复合加工过程热源模型及温度场研究、复合加工工具研制、FSJ-铣削复合加工机理分析以及复合加工获得的接头失效机理研究，解决该工艺中连接区域的能量耗散机制、工具性能演变规律以及接头失效机理等科学问题，从而为优化SiCp/Al复合材料FSJ-铣削复合加工工艺提供理论基础，为我国先进火箭发动机主承力构件研制和生产提供技术支持。

SiCp/Al复合材料拥有良好的性能，已广泛用于国防军工等领域。然而，由于SiCp/Al复合材料的二次加工比较困难，尤其是在连接方面，成为其广泛应用的主要障碍。搅拌摩擦连接属于固相连接，能够防止熔焊方法中孔隙、有害相等缺陷的生成。但是，由于SiC颗粒的高硬度，搅拌针表面往往会发生严重的磨损。此外，接头表面存在大量的飞边和毛刺，严重影响接头表面质量，需要后续的铣削或打磨加工。因此，如何降低搅拌工具的磨损和有效去除接头表面的飞边和毛刺是SiCp/Al复合材料搅拌摩擦连接中亟待解决的问题。本项目提出了搅拌摩擦连接-铣削复合加工创新思路，研制了一种搅拌摩擦连接-铣削复合加工工具，开展了SiCp/Al复合材料搅拌摩擦连接-铣削复合加工的相关研究。主要内容包括：.（1）建立了搅拌摩擦连接-铣削复合加工热源模型。研究了搅拌摩擦连接产热和铣削产热的分布，建立搅拌摩擦连接-铣削复合加工热源模型，讨论了复合加工过程中的能量耗散问题。.（2）研制了搅拌摩擦连接-铣削复合加工工具。开展了多种工具材料的试验研究，并对搅拌摩擦连接-铣削复合工具的结构进行创新设计，成功研制出搅拌摩擦连接-铣削复合加工工具。.（3）建立了搅拌摩擦连接准稳态过程的流场仿真模型，研究了材料流场的流动规律。.（4）研究了复合加工表面形貌特性、接头力学性能和腐蚀性能，分析了接头的失效机理。.本项目的研究为搅拌摩擦连接技术在SiCp/Al复合材料加工上大规模工程应用提供参考价值。