2CoB2的結(jié)構(gòu)、力學(xué)和熱力學(xué)性質(zhì)的影響。通過(guò)計(jì)算結(jié)合能和形成焓以及與Born-Huang標(biāo)準(zhǔn)比較，發(fā)現(xiàn)所有模型都滿足力學(xué)與熱力學(xué)穩(wěn)定條件。采用點(diǎn)缺陷理論確定了摻雜元素在Mo2CoB2晶體中的占位以及占位偏好。結(jié)果表明，Sc和Ti對(duì)Mo點(diǎn)位表現(xiàn)出強(qiáng)烈的占位偏好，V對(duì)Mo點(diǎn)位僅有較弱的占位偏好。同時(shí)，Cr、Mn、Fe、Cu和Zn對(duì)Co點(diǎn)位具有較弱的占位偏好，而Ni對(duì)Co點(diǎn)位有較強(qiáng)的占位偏好。通過(guò)對(duì)比計(jì)算得到德拜溫度，發(fā)現(xiàn)除Mo7TiCo4B8、Mo7VCo4B8和Mo7CrCo4B8外，其他摻雜模型的德拜溫度都低于未摻雜模型，這說(shuō)明實(shí)驗(yàn)中應(yīng)盡量避免在Mo2CoB2硬質(zhì)相中大量添加除Ti、V和Cr以外的過(guò)渡金屬元素。最后，除Cr摻雜模型外，其他摻雜模型的硬度計(jì)算結(jié)果都低于未摻雜的模型。同時(shí)，占據(jù)偏好點(diǎn)位的摻雜元素模型的硬度通常比占據(jù)非偏好點(diǎn)位的更高。本研究為開發(fā)性能更好的Mo2CoB2金屬陶瓷提供了理論支持。;The first-principles calculation was used to investigate the influence of doping fourth-period transition metal elements on the structural, mechanical, and thermal properties of Mo2CoB2. Through the calculation of cohesive energy and formation enthalpy as well as the calculation comparison between the obtained results and Born-Huang criterion, all doped compounds are thermodynamically and mechanically stable. Point defect theory was employed to determine the occupation sites and occupation preference of doped elements in the Mo2CoB2 crystal cell. Results show that Sc and Ti exhibit strong preference for Mo sites, and V has a weak preference for Mo sites. Additionally, Cr, Mn, Fe, Cu, and Zn have a weak preference for Co sites, and Ni has a strong preference for Co sites. Debye temperatures were obtained by the contrast calculation. The results reveal that except Mo7TiCo4B8, Mo7VCo4B8, and Mo7CrCo4B8, the doped models all have lower Debye temperatures than the undoped model, suggesting that except Ti, V, and Cr elements, the addition of transition metal elements of large quantity into the Mo2CoB2 hard phase should be avoided. Furthermore, except that of the Cr-doped model, the hardness of the doped models is lower than that of the undoped model, and the models with doped elements at preferential sites normally exhibit higher hardness than those at non-preferred sites do. This research provides theoretical basis for the development of Mo2CoB2-Co cermet with improved properties."/>
2CoB2-Co;cermet;first-principles;mechanical properties;Mo2CoB2-Co"/>