Abstract

In this study, low-cost Si was added to an Mg–8Gd–4Y–1Nd–0.5Zr alloy to regulate the intermetallic phases. The mechanical properties of 0, 0.5, and 1.0 wt% Si-added alloys were studied to explore the trade-off between the elastic modulus and strength. The microstructures were characterized through metallographic microscopy, scanning electron microscopy applying energy dispersive spectroscopy, and transmission electron microscopy. The microstructures demonstrated that Y₅Si₃ and GdSi phases formed and consumed the solid soluble Gd and Y elements, thus reducing the amount of precipitation and increasing the size of the β′ phase. Correlations between the elastic modulus and the intermetallic phase indicated that the Y₅Si₃ and GdSi phases formed by the addition of Si were the mainly responsible for the improvement in the elastic modulus. The change in strength through the addition of Si was calculated, and the results revealed that such an addition could increase the elastic modulus but with a reduction in the alloy strength. The addition of 0.5 wt% Si alloy resulted in a relatively high comprehensive performance, with an elastic modulus of 46 GPa, a tensile strength of 278 MPa, a yield strength of 226 MPa, and an elongation of 4.9% under a cast-T6 state.

Graphic Abstract

中文翻译：

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通过添加Si来调节金属间相来探索Mg-Gd-Y-Nd-Zr合金的弹性模量与强度之间的取舍

摘要

在这项研究中，低成本的Si被添加到Mg-8Gd-4Y-1Nd-0.5Zr合金中以调节金属间相。研究了0、0.5和1.0 wt％的含硅合金的机械性能，以探索弹性模量和强度之间的权衡。通过金相显微镜，使用能量色散光谱的扫描电子显微镜和透射电子显微镜对微观结构进行了表征。显微组织表明，Y ₅ Si ₃和GdSi相形成并消耗了固态可溶性Gd和Y元素，从而减少了沉淀量并增加了β '相的尺寸。弹性模量与金属间相的相关性表明，Y ₅ Si ₃通过添加Si形成的GdSi相和GdSi相是导致弹性模量提高的主要原因。计算出通过添加Si而引起的强度变化，结果表明，这种添加可以增加弹性模量，但是降低合金强度。添加0.5 wt％的Si合金具有相对较高的综合性能，在铸造T6状态下的弹性模量为46 GPa，拉伸强度为278 MPa，屈服强度为226 MPa，伸长率为4.9％。 。

图形摘要