The kinetics of a polytypic Laves phase transformation in TiCr2

被引：26

作者：

Baumann, Wolfgang ^{[1
]}

Leineweber, Andreas ^{[1
]}

Mittemeijer, Eric Jan ^{[1
,2
]}

机构：

[1] Max Planck Inst Met Res, D-70569 Stuttgart, Germany

[2] Univ Stuttgart, Inst Mat Sci, D-70569 Stuttgart, Germany

来源：

INTERMETALLICS | 2011年 / 19卷 / 04期

关键词：

Laves phases; Phase transformation; Defects: dislocation geometry and arrangement; Calorimetry; DIFFERENTIAL THERMAL-ANALYSIS; ANALYSIS MEASUREMENT SIGNAL; CALIBRATION; STABILITY; CR;

D O I：

10.1016/j.intermet.2010.11.027

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

A systematic investigation of the kinetics of the polytypic C36 reversible arrow C14 equilibrium phase (shear) transformation occurring at about 1545 K was performed. A recently developed calibration and desmearing procedure for a differential thermal analysis (DTA) apparatus [Baumann et al. Thermochim. Acta 2008; 472:50] enabled the investigation of the progress of this transformation by isochronal DTA measurements, both upon heating and cooling. A kinetic model was developed on basis of the modular approach, which considers overlapping nucleation, growth and impingement. It was shown that a thermal nucleation prevailed, i.e. pre-existing nuclei (here: arrays of dislocations) become activated as function of undercooling/overheating. The model fitting led to values for the equilibrium transformation temperature, the C36/C14 interface energy and the activation energy for growth. Moreover, a quantitative explanation was given of the composition-dependent thermal hysteresis of the transformation. (C) 2010 Elsevier Ltd. All rights reserved.

引用

页码：526 / 535

页数：10

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