Tensile deformation of texture-controlled titanium with high oxygen content at room temperature
Tensile deformation of texture-controlled titanium with high oxygen content at room temperature
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DOI：
10.1016/j.msea.2020.139660
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发表时间：
2020-06
期刊：
影响因子：
6.4
通讯作者：
M. Morita;Shogo Suzuki;Yaku Kato;Weibo Li;O. Umezawa
中科院分区：
文献类型：
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作者：
M. Morita;Shogo Suzuki;Yaku Kato;Weibo Li;O. Umezawa
钛和氧的合金已经证明了增加的拉伸强度，并且它们显示出用于一系列应用的前景。然而，高氧钛合金变形的微观组织和变形机制仍不清楚。为了解决这个知识的差距，我们研究了织构控制的Ti-O合金的拉伸性能和变形机制与高氧含量。我们制造了氧含量为0.058质量%、0.21质量%、0.41质量%、0.65质量%和0.71质量%的Ti-O合金。这些合金具有0001 10 1 <$0织构，并且它们沿着轧制方向变形。我们发现，氧含量与0.2%的屈服应力和抗拉强度的增加，这符合固溶强化规律。所有试样的总伸长率均高于20%。孪晶变形对强度和伸长率的影响很小，主要变形方式为滑移变形。当氧含量高于0.61质量%时，均匀延伸率和加工硬化率梯度增加。随着氧含量的增加，更多的晶粒发生双滑移。这是因为在拉伸变形下，锥体滑移被激活，并且锥体滑移的操作将晶体取向诱导到稳定取向。取向稳定的晶粒容易发生双重滑移。因此，位错经常被切割并相互缠结。结果表明，富氧Ti-O合金的加工硬化速率梯度增大，均匀延伸率和总延伸率提高。这些研究结果是有用的，以扩大氧利用作为钛合金元素。
Alloys of titanium and oxygen have demonstrated increased tensile strength, and they show promise for a range of applications. However, the microstructure and the mechanisms of high-oxygen titanium alloy deformation remain uncertain. To address this gap in knowledge, we investigated the tensile properties and deformation mechanisms of texture-controlled Ti–O alloys with high oxygen contents. We created Ti–O alloys with oxygen contents of 0.058%, 0.21%, 0.41%, 0.65%, and 0.71% by mass. These alloys possessed 0001 10 1¯ 0 texture, and they were deformed along the rolling direction. We found that oxygen content was correlated with increases in 0.2% proof stresses and tensile strengths, which conformed to the solid-solution strengthening law. All specimens exhibited total elongation of higher than 20%. Twin deformation had minimal effect on strength and elongation, and the major deformation mode was for slip deformation. The uniform elongation and gradient of the work hardening rate increased at oxygen contents above 0.61 mass%. As oxygen content increased, double slipping occurred in more grains. That is because pyramidal slip is activated, and its operation induces the crystal orientation to the stable orientation under tensile deformation. Double slipping easily occurs in a grain with stable orientation. Therefore, dislocations were frequently cut and tangled with each other. As a result, the gradient of the work hardening rate increased, and uniform and total elongation increased in Ti–O alloys with abundant oxygen. These findings are useful to extend oxygen utilization as an alloying element in Ti.