挤压铸造和重力铸造T4态Al-Zn-Mg-Cu合金的低周疲劳行为（英文）

发布时间：2018-06-05 13:42

本文选题：Al-Zn-Mg-Cu合金 + 挤压铸造　；参考：《Transactions of Nonferrous Metals Society of China》2015年11期

【摘要】：研究重力铸造和挤压铸造制备的Al-7.0Zn-2.5Mg-2.1Cu合金(T4态)的显微组织、力学性能和低周疲劳行为。结果表明:挤压铸造制备的合金铸造缺陷较少,二次枝晶间距较小,其静态力学性能明显优于重力铸造制备合金的;挤压铸造制备的合金具有优异的疲劳性能。在较低总应变幅下(小于0.4%),两种方法制备的合金均呈循环稳定特征;在较高总应变幅下均呈循环硬化特征,且挤压铸造制备的合金循环硬化程度高于重力铸造制备合金的。在重力铸造条件下,疲劳裂纹主要起源于缩松、缩孔处,并且易于沿着这些铸造缺陷扩展;在挤压铸造条件下,裂纹起源于表面和靠近表面处的滑移带、共晶相以及夹杂。
[Abstract]:The microstructure, mechanical properties and low cycle fatigue behavior of Al-7.0Zn-2.5Mg-2.1Cu alloy T4 prepared by gravity casting and squeeze casting were studied. The results show that the alloy prepared by squeeze casting has less defects and smaller secondary dendrite spacing, its static mechanical properties are obviously superior to those prepared by gravity casting, and the alloy prepared by squeeze casting has excellent fatigue properties. Under the lower total strain amplitude (less than 0.4%), the alloy prepared by the two methods has the characteristics of cyclic stability, and the alloy prepared by squeeze casting has a higher cyclic hardening degree than that prepared by gravity casting, while the alloy prepared by the squeeze casting has the characteristics of cyclic hardening at higher total strain amplitude than that of the alloy prepared by gravity casting. In gravity casting, fatigue cracks mainly originate from shrinkage and shrinkage, and are easy to propagate along these defects. In squeeze casting, the cracks originate from slip bands, eutectic phases and inclusions on and near the surface.
【作者单位】：华南理工大学机械与汽车工程学院;
【基金】：Project(2015A030312003)supported by the Guangdong Natural Science Foundation for Research Team,China Project(51374110)supported by the National Natural Science Foundation of China
【分类号】：TG146.21

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