Effects of yttrium on microstructure and mechanical properties of hot-extruded Mg–Zn–Y–Zr alloys
Effects of yttrium on microstructure and mechanical properties of hot-extruded Mg–Zn–Y–Zr alloys
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DOI：
10.1016/j.msea.2004.02.007
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发表时间：
2004-05
期刊：
影响因子：
6.4
通讯作者：
Ya Zhang;Xiaoqin Zeng;Liufa Liu;Chen Lu;Han Zhou;Qiang Li;Yan-ping Zhu
中科院分区：
文献类型：
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作者：
Ya Zhang;Xiaoqin Zeng;Liufa Liu;Chen Lu;Han Zhou;Qiang Li;Yan-ping Zhu
研究了钇对挤压Mg-Zn-Y-Zr合金显微组织和力学性能的影响。对3种变钇含量Mg-5.5Zn-xY-0.4Zr合金在不同温度下进行热挤压，研究其显微组织演变和动态再结晶过程。含钇量为0.74或1.35wt的合金。%的合金由α-Mg和大的i相颗粒组成，而高钇含量为1.72%的合金由α-Mg、i相和w相组成。对于钇含量为0.74或1.35wt的合金。%，在热挤压过程中形成细小的i相析出物。这些来自于破坏的i相口袋的细小析出物和颗粒对合金具有明显的强化作用。对于钇含量为1.72%的合金，在热挤压过程中未形成细小的i相析出。此外，在中等温度下挤压的合金中，w相的粗袋很难被破坏。因此，与钇含量为1.35%的合金相比，该合金的屈服强度适中，特别是在低温挤压时。此外，在所有合金的热挤压过程中，由于颗粒或析出物的挤压作用，DRX晶粒的生长受到抑制。
This article studied the effects of yttrium on microstructure and mechanical properties of extruded Mg–Zn–Y–Zr alloys. Three kinds of Mg–5.5Zn–xY–0.4Zr alloys with variable yttrium content were hot-extruded at different temperature to investigate the microstructure evolution and dynamic recrystallization (DRX) process of these alloys. The alloys with low yttrium content as 0.74 or 1.35wt.% consist of α-Mg and large I-phase particles, while the alloy with high yttrium content as 1.72% consists of α-Mg, I-phase and W-phase. For the alloys with low yttrium content as 0.74 or 1.35wt.%, fine I-phase precipitates formed during the hot extrusion process. These fine precipitates and particles, which are from destroyed I-phase pockets, provide obvious strengthening effects on the alloys. For the alloy with high yttrium content as 1.72%, fine I-phase precipitates did not form during the hot extrusion process. Further, coarse W-phase pockets were difficult to be destroyed in the alloy extruded at moderate temperature. As a result, the yield strength of this alloy is moderate compared to that of the alloy with yttrium content of 1.35%, especially when extruded at low temperature. Furthermore, it was observed that the growth of DRX grains was suppressed due to the pining effect of particles or precipitates during the hot extrusion process in all the alloys studied.