GOALI: Friction Stir Forming Process for Joining Dissimilar Metals

这项学术与工业联络资助机会（GOALI）奖支持研究一种新的成型工艺，以在不同材料之间创建机械连接。摩擦搅拌成形将通过实验，建模和材料分析进行研究。将测量固有的过程力和温度。实验研究了工艺参数对材料变形和接头强度的影响。对材料的热力学行为进行更精确的建模预测。将进行完整的金相分析，以表征搅拌摩擦成形对工作材料晶粒组织的影响。这种新的、高效的工艺对环境的影响相对较小，并且能够同时加热并将工作材料成型为坚固的异质材料接头。如果成功，这种新的连接工艺将产生一个更强、更轻的连接，完全由各种不同材料的母材制成。该过程是一个快速的一步过程，不需要外部紧固件，流体或任何其他材料。在传统的连接方法中，如熔合工艺，异种金属接头的连接强度是有限的。本研究的主要目标是建立力/热输入、材料结构、材料性能和由此产生的接头强度之间的联系。工作材料在高温下成形的性质将被充分表征，并提出的工作将有助于广泛的知识，材料成形的摩擦搅拌过程。这项研究将激发摩擦搅拌工艺的新途径和应用，并使其适用于广泛的材料。通用汽车公司是这项研究的合作伙伴，并将把这一工艺应用到他们的汽车车身结构制造中。

This Grant Opportunity for Academic Liason with Industry (GOALI) award supports the study of a new forming process to create a mechanical joint between dissimilar materials. Friction stir forming will be studied by experimental, modeling, and material analyses. The intrinsic process forces and temperature will be measured. The effect of process parameters on the material deformation and joint strength will be experimentally investigated. A more accurate modeling prediction of thermo-mechanical material behavior will be made. A complete metallurgical analysis will be conducted to characterize the effect of friction stir forming on the work material grain structure. This new, efficient process has a relatively small environmental footprint and will be capable of simultaneously heating and forming the work material into a strong dissimilar material joint. If successful, this new joining process will result in a stronger, lighter joint made entirely from the parent material in a variety of dissimilar materials. The process is a quick one-step process without the need for external fasteners, fluids, or any other material. In traditional joining methods, such as fusion processes, joint strength in dissimilar metal joints is limited. The major goal of this research is to establish the link among the force/heat input, material structure, material properties, and resulting joint strength. The nature of work material forming at high temperature will be fully characterized and the proposed work will contribute extensive knowledge about material forming by friction stir processes. This research will stimulate new avenues and applications for friction stir processes, and make them suitable for a wide range of materials. General Motors is a partner in the research and will implement the process into the manufacture of their automotive body structures.