时效成形/扩散连接异种铝合金的先期组织传递效应

Age forming / diffusion bonding is a kind of technology by which the connection of dissimilar aluminum alloy and the precise forming of component is connected to one. The creep connection, diffusion bonding, creep forming and precipitation hardening of dissimilar aluminum alloy are achieved by using the autoclave. The pre-precipitated structure significantly changes the subsequent phase transformation, which is called the transfer effect of the pre-precipitated structure and used as a technical principle of optimizing the structure of dissimilar aluminum alloy. According to this, the scientific question of controlling the microstructure during the process of precise forming—the transfer effect of pre-precipitated structure during the process of dynamic precipitation under the condition of composition change and creep deformation, is refined..In this project, the connection of dissimilar aluminum alloy, component forming, static precipitation, dynamic precipitation and microscopic phase-field method are combined, the component 2000 aluminum alloy/2000 Al-Li alloy is made by using the technology of Age forming / diffusion bonding. The relationship that the pre-precipitation structure response to the age technology at early stage is studied. The effect of creep forming, mutual diffusion, the relaxation of macro elastic stress, and nano interface mismatch stress on the transfer effect of pre-precipitated structure of dissimilar aluminum alloy matrix and connection layer is discussed, including the transfer degree, the transfer effect of dispersion degree and the orientation of precipitated phase. The effect mechanism caused by the static precipitation pre-precipitated structure during the process of dynamic precipitation is revealed. The scientific principle of controlling pre-precipitated structure and optimizing the matrix and connection layer structure of age forming / diffusion bonding is propounded. The elimination of non-uniform continous precipitated phase within the connecting surface is achieved to overcome the "weak link" problem.

时效成形/扩散连接是异种铝合金连接与构件精确成形为一体的技术，以热压罐实现异种铝合金的蠕变连接、扩散连接、蠕变成形、沉淀强化。先期组织显著改变随后相变过程，称为先期组织传递效应，可作为优化异种铝合金构件组织的一个技术原理和手段，据此，凝练出精确成形过程微观组织控制的科学问题—成分变化、蠕变变形条件下动态沉淀的先期组织传递效应。.本项目将异种铝合金连接、构件成形、静态沉淀、动态沉淀、微观相场模拟的研究相结合，时效成形/扩散连接技术制备2000系铝合金/2000系Al-Li合金构件。研究先期组织对先期时效工艺的响应关系，探讨蠕变变形、互扩散、宏观弹性应力松弛、纳观界面错配弹性应力对异种铝合金基体和连接层先期组织传递效应的影响，揭示静态沉淀先期组织在动态沉淀过程的影响机制，提出控制先期组织、优化时效成形/扩散连接的基体和连接层组织的科学原则。实现消除连接面非均匀连续沉淀相，克服“弱连接”问题。

时效成形/扩散连接是异种铝合金连接与构件精确成形为一体的技术，以热压罐实现异种铝合金的蠕变连接、扩散连接、蠕变成形、沉淀强化。先期组织显著改变随后相变过程，称为先期组织传递效应，可作为优化异种铝合金构件组织的一个技术原理和手段，据此，凝练出精确成形过程微观组织控制的科学问题—成分变化、蠕变变形条件下动态沉淀的先期组织传递效应。.本项目将异种铝合金连接、构件成形、静态沉淀、动态沉淀、微观相场模拟的研究相结合，时效成形/扩散连接技术制备2000系铝合金/2000系Al-Li合金构件。研究先期组织对先期时效工艺的响应关系，探讨蠕变变形、互扩散、宏观弹性应力松弛、纳观界面错配弹性应力对异种铝合金基体和连接层先期组织传递效应的影响，揭示静态沉淀先期组织在动态沉淀过程的影响机制，提出控制先期组织、优化时效成形/扩散连接的基体和连接层组织的科学原则。实现消除连接面非均匀连续沉淀相，克服“弱连接”问题。.项目按照计划完成了研究内容，实现了技术目标。有20篇论文发表在《Physica E：Low-Dimensional Systems and Nanostructures》、《Superlattices and Microstructures》等期刊上，SCI收录论文20篇，EI收录论文20篇；培养博士生4名、硕士生11名，按照计划完成了人才培养数量。参加境外学术会议2次，境内学术会议4次并做口头报告。基于项目研究成果，获得陕西省科学技术奖二等奖、2017年陕西省航空学会青年科技奖等科技奖励。