Journal of Materials Science & Technology ( IF 11.2 ) Pub Date : 2020-09-15 , DOI: 10.1016/j.jmst.2020.08.054 Xiaojie Zhou , Yuan Yao , Jian Zhang , Xiaomin Chen , Weiying Huang , Jing Pan , Haoran Wang , Maopeng Weng
A high-performance Mg-4.9Gd-3.2Y-1.1Zn-0.5 Zr alloy has been fabricated by multidirectional forging (MDF) after analyzing its compression behavior. The as-homogenized alloy exhibits a high activation energy Q of deformation (∼285 kJ/mol). The size of DRXed grains after compression tends to decrease as the Z-H parameter (Z) increases, showing a grain size exponent m of ∼4.0. Lamellar LPSO phases, kinking deformation, and bimodal microstructure are detected at the relatively low compression temperature of 350 and 400 °C, while sufficient DRX can be achieved at 500 °C, accompanied by the dissolution of lamellar LPSO. According to the processing maps, MDF was successfully conducted under an appropriate condition. After peak-aged at 200 °C for 78 h, the MDFed billet exhibits a tensile yield strength (TYS) of 331 and 305 MPa at room temperature and 200 °C, respectively. The high strength mainly results from the combination of fine grains, low Schmid factor for basal slip, sufficient ageing precipitates, and directionally arranged interdendritic LPSO phases, etc. This paper provides a feasible way for the fabrication of high-performance, low-RE-content, and large-scale Mg components for industrial production.
中文翻译:
分析其压缩行为后,通过多向锻造的高性能Mg-4.9Gd-3.2Y-1.1Zn-0.5Zr合金
通过分析其压缩行为,通过多方向锻造(MDF)制备了高性能Mg-4.9Gd-3.2Y-1.1Zn-0.5 Zr合金。均质合金表现出高的变形活化能Q(〜285 kJ / mol)。随着ZH参数(Z)的增加,压缩后的DRXd晶粒尺寸趋于减小,显示出晶粒尺寸指数m约4.0。在相对较低的350和400°C压缩温度下,可检测到层状LPSO相,扭结变形和双峰微观结构,而在500°C时可获得足够的DRX,并伴随着层状LPSO的溶解。根据处理图,在适当的条件下成功进行了MDF。在200°C时效达到峰值78 h后,MDF坯料在室温和200°C下分别显示出331和305 MPa的拉伸屈服强度(TYS)。高强度主要归因于细晶粒的结合,低的施密德因子(Schmid),基滑 老化的析出物和定向排列的枝晶间LPSO相等。本文为工业化生产高性能,低稀土含量的大规模镁组分提供了可行的方法。