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在讨论马氏体相变的形态学与动力学之前,先提一下马氏体前效应。马氏体前效应是指在马氏体形成前,在母相中所发生的一些变化。马氏体前效应有多种形式,例如,在冷却时母相的弹性常数可能会有些反常,这些弹性反常现象可能是由于点阵软化,即在冷却时母相弹性常数的下降;马氏体形成之前,母相也可能会出现因瓦效应;或者母相在马氏体形成之前还可能发生铁磁性转变,还可能有某些动力学的效应和振动效应,这些动力学反常现象称为声子模软化。此外,当冷却时,在马氏体形成之前,在母相中还可能出现某些竞争性的转变。体心立方β→ω
Before discussing the morphology and kinetics of martensitic transformation, let me first mention the pre-martensite effect. The pre-martensite effect refers to some changes that occur in the mother phase before the formation of martensite. For example, the elastic constants of the mother phase may be somewhat abnormal during cooling. These anomalies may be due to lattice softening, that is, the decrease of the elastic modulus of the mother phase during cooling. The martensite Prior to the formation of the matrix, there may also be the Invar effect; or the parent phase may also undergo ferromagnetic transformation prior to the formation of martensite, but also may have some kinetic and vibrational effects. These anomalous phenomena are called acoustic Sub-mode softening. In addition, some competitive transitions may also occur in the parent phase prior to martensite formation when cooled. Body-centered cubic β → ω