Lattice transformations related to unique mechanical effects
Lattice transformations related to unique mechanical effects
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与独特机械效应相关的晶格变换
DOI：
10.1007/bf02644571
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
J. Perkins
中科院分区：
文献类型：
--
作者：
J. Perkins
研究了表现出独特的“记忆”和/或“超弹性”形状记忆效应(SME)的各种大家族合金中的非热和应力诱发马氏体相变。这种力学效应与每个体系中马氏体相和预马氏体相反应路径的细节密切相关。各种“不常见”系统的一个共同特征是，通常的唯象晶体分析不能完全描述这些系统中的马氏体相变。研究了由晶格“洗牌”或低波长晶格波表示的附加特征，以及相变位错的机制作用。根据合金化(电子熵)对母相晶格不稳定性影响的证据，对TiNi、CuZn、AuCd、In-Tl等各种体系的共线进行了研究。前兆现象所反映的不稳定性在与具有类似动态晶格转变的系统中的观测有关时可以被赋予相当大的普遍性，例如第IV族碱基系统中的二阶“非热omega”晶格转变。强调了可逆性在SME合金马氏体相变中的重要性。并与更常见的非SME马氏体合金进行了比较。
Athermal and stress-induced martensitic transformations are examined in various alloys of the large family which exhibit the unique “memory” and/or “superelastic” shape memory effects (SME). Such mechanical effects are found to be intimately related to details of the martensitic and premartensitic reaction paths in each system. A common feature of various “uncommon” systems is that the usual phenomenological crystallographic analysis cannot completely describe the martensitic transformation in these systems. Addiional features represented by lattice “shuffles” or low-wavelength lattice waves, and the mechanistic role of transformation dislocations are examined. A common thread in various systems such as TiNi, CuZn, AuCd, In-Tl, and so forth, is viewed in terms of evidence related to alloying (electronic entropy) effects on lattice instability of the parent phase. Instability reflected by premonitory phenomena can be given considerable generality when related to observations in systems which exhibit similar dynamic lattice transitions, such as the second-order “athermal omega” lattice transition in Group IV-base systems. The importance of reversibility in martensitic transformation of SME alloys is emphasized. Comparisons with more common non-SME martensitic alloys are made.