Interaction between Al and other alloying atoms in α-Ti for designing high temperature titanium alloy
Interaction between Al and other alloying atoms in α-Ti for designing high temperature titanium alloy
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高温钛合金设计中Al与α-Ti中其他合金原子的相互作用
DOI：
10.1016/j.commatsci.2021.110620
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发表时间：
2021-06-04
影响因子：
3.3
通讯作者：
Hu, Qing-Miao
中科院分区：
文献类型：
--
作者：
Cao, Shuo;Zhang, Shang-Zhou;Hu, Qing-Miao
提高高温钛合金中Al的溶解度并抑制Ti3Al析出物的生长，可提高合金的热强度和热稳定性。原则上，这可以通过添加一些其他吸引Al的合金原子来实现，从而在合金中充当Al的陷阱。在本工作中，采用第一原理方法计算了Al与合金原子X之间的相互作用能，其中X涵盖了化学元素周期表（CEPT）中所有过渡金属（TM）和贵金属（NM）元素，以筛选Al的陷阱。考虑了温度（以Mo-Al相互作用为例）以及新发现的合金原子的偏心位点（Acta Mater. 197, 2020, 91）对相互作用能的影响。我们表明，在 CEPT 早期，Al 和 TM 合金原子之间的相互作用很弱。中间的 TM 合金原子吸引 Al，但后面的 TM 和 NM 原子排斥 Al。在有限温度下，晶格振动增强，而构型熵减弱Mo-Al吸引力。这两种效应随着温度的升高而变得更强。通过分析电子态密度和键合电荷密度揭示了 X-Al 相互作用的物理起源。 Mo、Tc、Ru、W、Re 和 Os 等合金原子被认为有利于高温钛合金的强度和热稳定性。该工作有助于高温钛合金的合理设计。
Increasing the solubility of Al and inhibiting the growth of Ti3Al precipitates in high temperature titanium alloy improve both the thermal strength and thermal stability of the alloy. In principle, this may be achieved by adding some other alloying atoms which attract Al so as to serve as traps for Al in the alloy. In the present work, the interaction energies between Al and alloying atoms X with X covering all the transition metal (TM) and noble metal (NM) elements in the Chemical Elemental Period Table (CEPT) are calculated by using a first principles method in order to screen the traps for Al. The effects of temperature (taking Mo-Al interaction as an example) as well as the newly found off-center site-occupation of alloying atoms (Acta Mater. 197, 2020, 91) on the interaction energies are considered. We show that the interactions between Al and the TM alloying atoms early in the CEPT are weak. The middle TM alloying atoms attract but the late TM and NM ones repel Al. At finite temperature, the lattice vibration enhances whereas the configurational entropy weakens the Mo-Al attraction. Both effects become stronger with increasing temperature. The physical origins underlying the X-Al interactions are revealed by analyzing the electronic density of states and bonding charge density. Alloying atoms such as Mo, Tc, Ru, W, Re, and Os are identified to benefit the strength and thermal stability of high temperature titanium alloys. This work is helpful to the rational design of high temperature titanium alloys.