Substantially strengthening a dual-phase titanium alloy by moderate oxygen doping
Substantially strengthening a dual-phase titanium alloy by moderate oxygen doping
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DOI：
10.1016/j.scriptamat.2022.115236
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发表时间：
2023-03
影响因子：
6
通讯作者：
Yu Fu;W. Xiao;Shiteng Zhao;Lei Ren;Junshuai Wang;J. Rong;Juan Li;Xinqing Zhao;Chao-Li Ma
中科院分区：
文献类型：
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作者：
Yu Fu;W. Xiao;Shiteng Zhao;Lei Ren;Junshuai Wang;J. Rong;Juan Li;Xinqing Zhao;Chao-Li Ma
作为有害成分之一的氧，即使是少量的氧，也会显著降低钛合金的延展性。在此，等轴双相Ti-8 Nb-2Fe-0.66O（wt.%）研制了一种屈服强度为1386 MPa、延伸率为10.8%的高性能合金。含氧合金的强度比无氧基合金高87%，而延展性损失是微不足道的。氧杂质的作用是双重的：通过钉扎位错和抑制应力诱发马氏体相变，导致显著的固溶强化;氧掺杂的具有α基织构的等轴α + β双相促进了多个<c+a>型和<a>-型位错活动，保证了良好的塑性。本工作为开发高强度钛合金提供了一条新途径，即通过掺杂氧元素，充分利用氧的有利强化因素，同时避免其有害的脆化效应。
As one of the detrimental ingredients, oxygen can, even in a small amount, substantially reduce the ductility of Ti alloys. Here, rather than being discouraged by the negative effects of oxygen on ductility, an equiaxed dual-phase Ti-8Nb-2Fe-0.66O (wt.%) alloy showing ultrahigh yield strength (1386 MPa) and good tensile ductility (fracture elongation ∼10.8%) was developed. The oxygen-containing alloy is 87% stronger than the oxygen-free base alloy whereas the ductility loss is marginal. The effects of oxygen interstitials can be twofold: they led to significant solid-solution strengthening by pinning dislocations and suppressing stress-induced martensitic transformation; the equiaxed α + β dual-phase with basal α texture doped by oxygen promoted multiple <c+a>-type and <a>-type dislocation activities that guaranteed good ductility. This work demonstrates a new avenue to develop high-strength Ti alloys by doping oxygen interstitials, which takes full advantage of the beneficial strengthening factor of oxygen while avoiding its detrimental embrittlement effect.