基本信息
项目批准号：51705027
申请代码：E0508
项目名称：铝合金差速双轴肩搅拌摩擦焊非对称成形机理(lǐ)及力學(xué)性能(néng)控制研究
项目负责人：王非凡
依托单位：北京宇航系统工程研究所
研究期限：2018-01-01 至 2020-12-31
资助经费：25.0（万元）

项目摘要
中文(wén)摘要：
随着我國(guó)航天事业持续快速发展，双轴肩搅拌摩擦焊被选為(wèi)未来高性能(néng)大型共底贮箱制造的关键技术之一，但接头内部成形弱區(qū)问题严重影响了构件质量可(kě)靠性。针对成形弱區(qū)问题，本项目以铝合金双轴肩搅拌摩擦焊為(wèi)研究对象，突破常规对称成形设计，提出并开展了主动差速控制非对称成形工艺理(lǐ)论与试验研究。以接头成形弱區(qū)為(wèi)研究重点，分(fēn)析提取接头形貌关键特征量，并建立其随工艺参数的演变模型。通过试验与数值模拟相结合的手段，研究焊接温度场及流场耦合演变规律，揭示接头成形弱區(qū)形成本质，阐明宏观塑性变形及微观界面消失协同作用(yòng)下的非对称成形机理(lǐ)。研究接头晶粒、沉淀相和织构取向，揭示非对称成形对接头组织非均匀性的影响规律，结合接头整體(tǐ)与局部力學(xué)性能(néng)相关性分(fēn)析，建立非对称成形条件下接头力學(xué)控制模型。研究成果将直接為(wèi)铝合金差速双轴肩搅拌摩擦焊工艺规范设计提供参考，该项目的实施将有(yǒu)力推动搅拌摩擦焊的理(lǐ)论发展及其在航空航天等领域的应用(yòng)。
英文(wén)摘要：
With the rapid development of China's aerospace industry, bobbin tool friction stir welding (BT-FSW) has been expected to be a key technology in manufacturing of the large scale common bulkhead tank. However, it has been frequently reported that a bad-formation zone remains in the joint, which significantly intimidates the joint strength. In this study, the dual-rotational BT-FSW is proposed to introduce an asymmetrical effect on the weld formation, to enhance the material flow and improve the joint strength. To understand the nature of the weak flow zone, key features of the shape will be figured out based on the microstructure observation. Meanwhile, a coupled thermo-mechanical finite element model of BT-FSW is going to be established to visualize the plastic material flowing behavior. A thoroughly investigation on the evolution of grain size, precipitates and crystallographic texture will be carried out, for getting insight into the impact of dual-rotational BT-FSW on the joint microstructure. Moreover, a comparison study is proposed on global and local mechanical properties of the dual-rotation BT-FSW joint, to explore the relation between the inhomogeneous microstructure and the corresponding mechanical properties. At last, the welding parameter window will be figured out for future mechanical properties optimization. This work is not only expected to be a complement of the theory of the friction stir welding technology, but also an effectively theory guide for the future application of BT-FSW in aerospace industry.
 
                                                                                                                                                                                                     ——来自https://kd.nsfc.gov.cn/