无机材料学报2024，Vol.39Issue(2)：225-235,11.DOI:10.15541/jim20230188
硫族MAX相硼化物的物相稳定性和性能预测
Predictions of Phase Stability and Properties of S-group Elements Containing MAX Borides
摘要
Abstract
Zr2SB,Hf2SB,Zr2SeB,Hf2SeB,and Hf2TeB are all recently discovered S-group elements containing MAX-phase borides,which attract much attention since the MAX phase borides are significantly unlike the typical MAX phases.Here,the phase stability,mechanical properties and thermal properties of MAX phase borides(M = Zr,Hf,A = S,Se,Te)were studied by using first principles and"linear optimization method",bond stiffness model and quasi-simple harmonic approximation.The results of the theoretical analysis were consistent with the currently available experimental results.Only M2AB was found to be stable after thermodynamic and intrinsic stability analysis.The shorter M-A bond and M-B bond lengths cause bond stiffness of Hf lineage higher than that of Zr,which also leads to the higher hardness of Hf lineage compound than that of Zr.the A site element goes from S to Se and to Te,the bond lengths of M-B and M-A are gradually increased,which lead to decrease in the elastic modulus.Moreover,the bulk modulus of these compounds is determined by their average chemical bond stiffness.Importantly,the high kmin/kmax(stiffness ratio of the weakest and the strongest bonds)shows that these MAX phases are inherently brittle,different from conventional MAX phase.Including the contribution of lattice vibration(phonon)and electron excitation,the isobaric heat capacity and heat expansion coefficient of M2AB increase rapidly with increasing the temperature below 300 K and then the rise rate gradually decreases,similar to other MAX phases.Lower bond stiffness results in an overall higher TEC of MAX phase borides in the Zr lineage than in the Hf lineage.The TEC values of these compounds in the 300-1300 K interval are consistent with most of the MAX and MAB phases.关键词
第一性原理/MAX相硼化物/物相稳定性/力学行为/热学性能Key words
first-principle/MAX phase boride/phase stability/mechanical property/thermal property分类
化学化工引用本文复制引用
张宇晨,陆知遥,赫晓东,宋广平,朱春城,郑永挺,柏跃磊..硫族MAX相硼化物的物相稳定性和性能预测[J].无机材料学报,2024,39(2):225-235,11.基金项目
国家自然科学基金面上项目(51972080) （51972080）
特种环境复合材料技术国家级重点实验室基金(JCKYS2022603C028)National Natural Science Foundation of China(51972080) （JCKYS2022603C028）
National Key Laboratory Fund of Special Environmental Composites Technology(JCKYS2022603C028) （JCKYS2022603C028）
