中文摘要：

利用Gleeble-1500热模拟机对LC9铝合金试样进行高温等温热挤压实验，模拟搅拌摩擦焊过程中接头热力影响区材料的变形行为，研究了变形温度在250℃-480℃、应变速率在0．01s-1～5s1条件下材料的流变行为。结果表明，LC9铝合金搅拌摩擦焊焊接头的热力影响区金属塑在变形过程中受到热和力的共同作用，其变形行为可用不同变形条件的高温热挤压试样进行模拟。LC9铝合金变形的流变应力与温度、应变速率之间的关系可表示为：ε=2．704×10^10[sinh（0．009909（r）×exp[-135．879×10^3／（RT）]。通过组织和硬度对比，发现铝合金热挤压试样组织、硬度与搅拌摩擦焊焊缝热力影响区组织、硬度分布具有很好的相似性。

英文摘要：

In order to simulate the deformation of metals in thermo-mechanically affected zone during friction stir welding, hot compression tests of LC9 aluminum alloy samples were performed on Gleeble-1500 machine, with a temperature ranging from 250℃-480℃and strain rate ranging form 0.01s-1 -5s-1. The results show that the thermo-meehanically affected zone of LC9 aluminum alloy in the friction stir welding weld is under the combined action of the heat and power. The deformational behavior can be simulated by hot compression tests in different deformation conditions. The relationship of flow stress with temperature and strain rate of LC9 Aluminum Alloy can be described ase = 2. 704 × 10^10 [ sinh（0. 009909σ） 36.79 × exp[-135. 879 × 103/（RT） ]. The mierostructure and hardness of the thermo-mechanieally affected zone of friction stir welding weld and the hot compression sample show the same characteristics, and this suggests that the constitutive equations of hot compression tests can be used to describe the material constitutive behavior and friction stir welding thermo-mechanieally affected zone of LC9 aluminum alloy.