Achieving superior fatigue strength in a powder-metallurgy titanium alloy via in-situ globularization during hot isostatic pressing
Achieving superior fatigue strength in a powder-metallurgy titanium alloy via in-situ globularization during hot isostatic pressing
复制标题
通过热等静压过程中的原位球化使粉末冶金钛合金实现优异的疲劳强度
DOI：
10.1016/j.scriptamat.2023.115345
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发表时间：
2023
影响因子：
6
通讯作者：
Shi, Y.S.
中科院分区：
文献类型：
--
作者：
Guo, R.P.;Cheng, M.;Zhang, C.J.;Qiao, J.W.;Cai, C.;Wang, Q.J.;Xu, D.S.;Xu, L.;Yang, R.;Shi, Y.S.
粉末冶金钛合金具有优异的准静态力学性能，但疲劳性能较低，严重限制了其在航空航天领域的应用。在这里，我们实现了一个上级疲劳强度为600 MPa的近αPM钛合金，使用两步热等静压方案，在此期间，超过80体积%，（体积分数）随机取向的等轴晶。疲劳强度的显著提高（约25%）主要归因于层状组织的原位球化，从而提高了裂纹形核阻力和降低了短裂纹的扩展速率。本研究结果为制备高疲劳强度粉末冶金钛合金提供了一条有用的途径。
Powder-metallurgy (PM) titanium alloys exhibit outstanding quasistatic-mechanical properties, but suffer from low fatigue performance, which severely limits their applications in aerospace. Here, we achieve a superior fatigue strength of 600 MPa in a near-αPM titanium alloy, using a two-step hot-isostatic-pressing scheme, during which more than 80 vol.% (volume fraction) randomly orientated equiaxed grains was obtained. The largely improved fatigue strength (∼ 25%) is mainly attributed to thein-situglobularization of the lamella-like microstructure, leading to higher crack nucleation resistance and lower growth rates of short cracks. The present findings offer a useful route for fabricating PM titanium alloys with high fatigue strengths.