Abstract Mechanical behavior and texture evolution of Mg rare-earth alloy WE43 is investigated for strain-rates 10−3/s to upwards of 105/s for the two material conditions - as-cast (AC) and T6 age hardened, rolled plate (RT6). The high strain-rate behavior is tested using both Taylor cylinder impact tests (TC) and split Hopkinson pressure bar tests (SHB) and bulk textures are obtained using neutron diffraction. Unlike the quasi-static strained material, AC and RT6 SHB retained high hardening rates throughout the test, even up to 30% true strain. Moreover, the high strain-rate data revealed that the RT6 material has a much higher strength than the AC material, but similar hardening rates despite significantly different initial texture. The flow stress near yield increased up to 10% for RT6 and up to 30% for AC as the strain-rate increased six orders of magnitude from quasi-static rates 10−3/s to 103/s. Neither material exhibited significant plastic anisotropy over the broad range of strain rates, despite the fact that the RT6 material had a moderately strong initial texture. In the TC tests, the geometric cross-sectional changes and texture along the cylinder from the cylindrical sample foot to head are measured and from the neutron diffraction texture analysis, upper-bound estimates of twin volume fraction are obtained as well as dislocation density from analyzing diffraction peak broadening. Recorded geometrical changes along several loading directions show that the material has deformed homogeneously under impact. Analysis of deformed textures indicates that { 10 1 ¯ 2 } extension deformation twinning occurred in the RT6 condition over the range of strain rates, with an upper bound estimate of 40% twin volume fraction for approximately 0.10-0.25 true strain. The peak texture components after the impact have their c-axes closely aligned with the impact direction. These observations are presented and rationalized in the paper.

中文翻译：

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WE43 镁稀土合金在 Split-Hopkinson 压力棒和泰勒冲击气缸测试中的力学行为和织构演变

摘要 研究了镁稀土合金 WE43 的机械行为和织构演变，在应变速率为 10-3/s 至 105/s 以上两种材料条件下 - 铸态 (AC) 和 T6 时效硬化轧制板 ( RT6）。使用泰勒圆柱冲击试验 (TC) 和分裂霍普金森压力棒试验 (SHB) 测试高应变率行为，并使用中子衍射获得整体纹理。与准静态应变材料不同，AC 和 RT6 SHB 在整个测试过程中保持高硬化率，甚至高达 30% 的真实应变。此外，高应变率数据表明，RT6 材料的强度比 AC 材料高得多，但尽管初始纹理显着不同，但硬化率相似。随着应变速率从准静态速率 10−3/s 增加到 103/s 六个数量级，RT6 接近屈服的流动应力增加了 10%，AC 增加了 30%。尽管 RT6 材料具有中等强度的初始纹理，但两种材料都没有在广泛的应变率范围内表现出显着的塑性各向异性。在 TC 测试中，测量了从圆柱样品脚到头部沿圆柱的几何横截面变化和纹理，并从中子衍射纹理分析中获得了孪晶体积分数的上限估计值以及分析中的位错密度衍射峰展宽。沿几个加载方向记录的几何变化表明材料在冲击下均匀变形。变形织构的分析表明，{10 1 ¯ 2 } 拉伸变形孪晶发生在 RT6 条件下的应变率范围内，对于大约 0.10-0.25 的真实应变，上限估计为 40% 孪晶体积分数。撞击后的峰值纹理分量的 c 轴与撞击方向紧密对齐。这些观察结果在论文中被提出和合理化。