Development of Ultra-High Strength and Ductile Mg–Gd–Y–Zn–Zr Alloys by Extrusion with Forced Air Cooling
Development of Ultra-High Strength and Ductile Mg–Gd–Y–Zn–Zr Alloys by Extrusion with Forced Air Cooling
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DOI：
10.1007/978-3-319-52392-7_7
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Chao Xu;T. Nakata;M. Y. Zheng;S. Kamado
中科院分区：
文献类型：
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作者：
Chao Xu;T. Nakata;M. Y. Zheng;S. Kamado
含重稀土镁合金因其显著的时效硬化效应而受到广泛关注。Mg-HRE合金的挤压通常需要高的冲压力，导致在挤压期间产生热。本研究采用简单的空冷工艺，通过对Mg-8.2Gd-3.8Y-1 Zn-0.4Zr（wt%）合金组织的调控，成功地制备出了具有良好塑性的高强度Mg-8.2Gd-3.8Y-1 Zn-0.4Zr合金。挤出过程中的冷却可以控制动态再结晶（DRX）率、晶粒尺寸和织构，即强制风冷降低了挤出温度，使挤出物在挤出后快速冷却。因此，挤压与强制空气冷却的合金表现出高的拉伸屈服强度为378 MPa，436 MPa的极限拉伸强度和高的断裂伸长率为12.5%，由于双峰微观结构组成的较细的DRX晶粒具有相对随机的取向和粗的未再结晶晶粒具有较强的基底纤维织构。
Magnesium alloys containing heavy rare earth metals (HRE) have been attracting wide attention due to their remarkable age-hardening response. Extrusion of Mg-HRE alloys generally requires high ram force, leading to heat generation during the extrusion. In this study, by simply utilizing forced air cooling, high strength Mg–8.2Gd–3.8Y–1Zn–0.4Zr (wt%) alloy with good ductility was successfully developed via tailoring the microstructure . The dynamic recrystallization (DRX) ratio, grain size and texture can be controlled by cooling during the extrusion process, that is, the forced air cooling reduces the extrusion temperature and brings about rapid cooling of the extrudate after extrusion. Consequently, the alloy extruded with forced air cooling exhibits high tensile yield strength of 378 MPa, ultimate tensile strength of 436 MPa and high elongation to failure of 12.5% due to a bimodal microstructure consisting of finer DRXed grains with relatively random orientations and coarse unrecrystallized grains with a strong basal fiber texture.