搅拌摩擦加工对稀土镁合金组织与性能的影响

制定三种参数对Mg-Nd-Zn-Zr稀土镁合金进行搅拌摩擦加工处理(FSP),通过金相实验观察了合金加工前后的显微组织,发现该工艺在很大程度上细化了合金晶粒;通过拉伸实验测量了合金加工前后的常温及170℃高温力学性能,结果发现合金的力学性能较加工前有明显的提高和改善,且有很好的高温性能。分析表明,合金性能的提高主要源于合金晶粒的细化及FSP加工过程中的沉淀强化作用,而合金晶粒的细化主要是因为在加工过程中合金发生动态再结晶所致,同时合金组织与性能的变化与加工参数也有关。

Effect of friction stir processing on microstructure and properties of cast Mg-Nd-Zn-Zr

Friction stir processing was applied to cast Mg-Nd-Zn-Zr with 3 different parameters.The dynamic recrystallized structure of the material was observed by employing optical and electron microscopy.The microstructure features indicate that FSP can refine the grains significantly.The tensile mechanical properties were evaluated at room temperature in transverse direction respect to the properties before processing.Tensile tests were also performed at room temperature and the same strain rate in the nugget zone.The results show that the properties after processed are improved considerably compared with the unprocessed.The analysis revealed that the properties improvement were due to refinement of the grains,while the refinement was main result from dynamic recrystallization during FSP.Moreover,the microstructure properties and modification are great related to the processing parameter.