Microstructure evolution and segregation behavior of thixoformed Al-Cu-Mg-Mn alloy  

Al-Cu-Mg-Mn合金触变成形显微组织演变与偏析行为（英文）

作　　者：陈刚[1] 周焘 王博 刘洪伟[1] 韩飞[1] 

机构地区：[1]哈尔滨工业大学(威海)材料科学与工程学院,威海264209 [2]空军装备部重点型号部,北京100081 [3]北京卫星制造厂,北京100094

出　　处：《Transactions of Nonferrous Metals Society of China》2016年第1期39-50,共12页中国有色金属学报（英文版）

基　　金：Project(51405100) supported by the National Natural Science Foundation of China;Project(2014M551233) supported by the Postdoctoral Science Foundation of China;Project(HIT.NSRIF.2015112) supported by the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology,China;Project(HIT(WH)201313) supported by the Scientific Research Foundation of Harbin Institute of Technology at Weihai,China

摘　　要：A commercial wrought Al-Cu-Mg-Mn alloy（2024） was thixoformed based on the recrystallization and partial melting（RAP） route, and the microstructure evolution and segregation behavior during the indirect thixoforming process were studied. The results show that fine spheroidal microstructures can be obtained by partial remelting of commercial extruded 2024 alloys without additional thermomechanical processing. During the indirect thixoforming, the stress distribution can be optimized by increasing the thickness of base region. Under three-dimensional compression stress state, the microstructures are homogeneous among different regions with no evidence of liquid segregation and micro-porosities, and the grains in the columns are deformed plastically. The distribution of tensile mechanical properties is consistent with the microstructures. Moreover, the distribution of deformation mechanism was discussed, and a technical method for improving the stress distribution was proposed.采用再结晶与重熔法(RAP)制备一种Al-Cu-Mg-Mn合金(2024)半固态坯料,研究间接触变成形过程中的显微组织演变和偏析行为。结果表明:对商用挤压态2024铝合金进行二次重熔处理,可以直接得到具有细小球晶组织的半固态坯料。在间接触变成形过程中增加底部区域厚度可以得到更好的应力分布状态。在三向压应力条件下,构件不同区域的显微组织较为均匀,没有发现明显的固液偏析和微观缩孔,而且柱体处的晶粒产生了明显的塑性变形。构件不同位置的力学性能和显微组织呈现出良好的对应关系。此外,还讨论了成形过程中的变形机制分布规律,并且提出了一种优化成形应力分布状态的工艺方法。

关 键 词：aluminum alloy SEMI-SOLID THIXOFORMING SEGREGATION microstructure 

分 类 号：TG146.21[一般工业技术—材料科学与工程]