Microstructure and mechanical properties of large-scale Mg-Gd-Y-Zn-Mn alloys prepared through semi-continuous casting
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第17期
论文作者：Kui Wang Jingfeng Wang Xiaoxu Dou Shijie Liu Yanwu Cai Jinxing Wang Fusheng Pan
文章页码：72 - 82
摘 要：Large-scale Mg-8Gd-4Y-1Zn-Mn（wt.%） alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting. Chemical composition, microstructure and mechanical properties at different locations of the samples with as-cast, T4 and T6 heat-treated states, respectively,were investigated. No obvious macro segregation has been detected in the high-quality alloy ingot.The main eutectic structures at all different locations are composed of α-Mg, Mg3RE-type, Mg5RE-type and LPSO phases. At the edge of ingot, the unusual casting twins including 10-12 extension twins and 10-11 compression twins were observed due to the intensive internal stress. In T4 heat-treated alloy, the micro segregation was eliminated. The remained phases were α-Mg and LPSO phase. Combined with the remarkable age-hardening response, T6 samples exhibits improved mechanical properties at ambient temperature, which derives from the dense prismatic β’ precipitates and profuse basal γ’ precipitates.
Kui Wang1,2，Jingfeng Wang1，Xiaoxu Dou1，Shijie Liu1，Yanwu Cai1，Jinxing Wang1，Fusheng Pan1
1. National Engineering Research Center for Magnesium Alloys, College of Materials Science and Engineering, Chongqing University
摘 要：Large-scale Mg-8Gd-4Y-1Zn-Mn（wt.%） alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting. Chemical composition, microstructure and mechanical properties at different locations of the samples with as-cast, T4 and T6 heat-treated states, respectively,were investigated. No obvious macro segregation has been detected in the high-quality alloy ingot.The main eutectic structures at all different locations are composed of α-Mg, Mg3RE-type, Mg5RE-type and LPSO phases. At the edge of ingot, the unusual casting twins including 10-12 extension twins and 10-11 compression twins were observed due to the intensive internal stress. In T4 heat-treated alloy, the micro segregation was eliminated. The remained phases were α-Mg and LPSO phase. Combined with the remarkable age-hardening response, T6 samples exhibits improved mechanical properties at ambient temperature, which derives from the dense prismatic β’ precipitates and profuse basal γ’ precipitates.
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