Effect of Dynamically Recrystallized Grain Size on the Tensile Properties and Vibration Fracture Resistance of Friction Stirred 5052 Alloy
Effect of Dynamically Recrystallized Grain Size on the Tensile Properties and Vibration Fracture Resistance of Friction Stirred 5052 Alloy
复制标题
动态再结晶晶粒尺寸对搅拌摩擦5052合金拉伸性能和抗振动断裂性能的影响
DOI：
10.2320/matertrans.47.2405
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发表时间：
2006
影响因子：
1.2
通讯作者：
Li
中科院分区：
文献类型：
--
作者：
K. Huang;T. Lui;Li
对5052H34铝镁合金板材进行了退火热处理，然后在500~1500转/分的不同转速下进行搅拌摩擦处理，以研究其拉伸性能和抗振动断裂性能。实验结果表明，在搅拌区可以观察到晶粒细化，平均晶粒尺寸在5~16 mm之间。根据观察到的显微组织和拉伸变形抗力数据，可以确定Hall-Petch方程的Ky斜率。搅拌区细小的晶粒度是摩擦搅拌试件的共同特征。不同的转速对应的晶粒度不同，这可以归因于搅拌摩擦过程中的动态再结晶。研究了晶粒度对搅拌区振动断裂抗力的影响。结果表明，搅拌区的振动断裂抗力随转速的增加而降低。较高的转速导致晶粒度的增大对振动传播阻力不利，晶粒度的微小变化会导致D-N曲线第一阶段的持续时间发生显著变化。研究发现，内裂纹扩展行为是影响振动断裂抗力的主要控制因素。这一结果与裂纹扩展速率的变化规律相吻合。[DOI：10.2320/MATERTRA.47.2405]
5052H34 Al-Mg plates were annealed and then friction stir processed at various rotation speeds ranging from 500 to 1500 rpm to investigate the tensile properties and vibration fracture resistance. The experimental results indicate that grain refinement could be observed at the stir zone with an average grain size varying from 5–16 mm. Based on the observed microstructure and tensile deformation resistance data, the ky slope value of the Hall-Petch equation can be determined. A refined grain size in the stir zone is a common feature of the friction stirred specimens. Different rotation speeds have different corresponding grain sizes and this can be attributed to dynamic recrystallization during friction stir processing (FSP). The effect of grain size on vibration fracture resistance in the stir zone was also examined. Results show that the vibration fracture resistance of the stir zone decreases with increasing the rotation speed. An increase in grain size due to higher rotation speed is detrimental to the vibration propagation resistance, and a small variation in grain size can result in significant changes in the duration of stage I of the D-N curves. The inward crack propagation behavior was found to be the main controlling factor on vibration fracture resistance. This result agrees with the variation in crack propagation rate. [doi:10.2320/matertrans.47.2405]