NiTi合金中B2→R和R→M相变的Landau理论

NiTi合金中B2→R和R→M相变的Landau理论 LANDAU THEORY OF THE B 2→ R AND R → M PHASE TRANSITIONS IN NiTi ALLOY 钱华 Qian Hua first-author 王子孝 Wang Zixiao 本文用Landau理论研究近等原子比NiTi合金中B 2 →R和R→M相变的机制。B 2 →R相变由电荷密度波（CDW）引起,R→M相变属切变机制,由"1/2"型软横声模与单胞畸变耦合造成。R相具有P1m空间群,马氏体相具有P2 1 /m空间群。对称破缺导致R相、M相变体的自协调变体群,R 2 相,R相和M相之间具有一定的结晶学取相关系。理论与实验相符。 The mechanism of B 2 →R and R→M phase transition in near stoichiometric NiTi alloy has been studied。 B 2 →R transition is due to the formation of CDW′s. R→M transition has the shear mechanism, caused by soft "1/2" type TA phonon coupled with the strain。 The symmetry of R phase is P1m and that of M phase is P2 1 /m. The broken symmetry cause the self—accomo darien groups of variants. There is certain crystallography relationship between the B 2 、R and M phases. The theory is in accordance with the experiments. 朗道理论 相变 镍钛合金 电荷密度波 马氏体 Landau theory phase transition NiTi alloy Charge density wave Martensite 国家自然科学基金(61672102) 1988-01-01 2021-04-01 1