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通过测量电导率研究了Cu-Cr合金450℃的相变动力学。利用电导率与新相析出量之间的关系计算新相析出体积分数,推导出450℃下的Avrami经验方程和电导率方程。在此基础上作450℃时效时的相变动力学“S”曲线。并用固溶体脱溶分解反应机理的积分方程验证Avrami经验方程的正确性。通过同样的方法计算出420~600℃的n和b值,并利用Cu-Cr合金在不同温度下的n和b值作Cu-Cr合金等温转变动力学“C”曲线。450℃×1 h时效Cu-Cr合金主要为GP区,450℃×8 h时效Cu-Cr合金主要析出相为具有cube-on-cube位向关系的有序fcc富Cr相。
The phase transition kinetics of Cu-Cr alloy at 450 ℃ was studied by measuring the electrical conductivity. The precipitation volume fraction of new phase was calculated by the relationship between the conductivity and the precipitated amount of new phase. The Avrami empirical equation and conductivity equation at 450 ° C were derived. On the basis of this, the kinetics of phase transformation at 450 ℃ aging is shown as “S” curve. The correctness of the Avrami empirical equation is verified by the integral equation of the mechanism of solid solution dissolution and decomposition. The same method was used to calculate the n and b values of 420-600 ℃. The kinetic “C” curve of isothermal transformation of Cu-Cr alloy was also obtained by using the n and b values of Cu-Cr alloy at different temperatures. The main Cu-Cr alloy is the GP zone at 450 ℃ for 1 h, and the main precipitated phase of Cu-Cr alloy at 450 ℃ for 8 h is the ordered fcc Cr-rich phase with cube-on-cube orientation.