为了明确Fe基块体非晶材料的晶化过程,通过铜模吸铸法制备了Fe45Co7Cr15Mo10Y2B6C15块体非晶合金,采用连续和等温差热扫描量热法对非晶合金在1 000 K以下的晶化动力过程进行了研究.研究表明:在973 K时效后的晶化产物为铁的碳化物;晶化过程的激活能达到了555.9 kJ/mol,非晶热稳定性良好;Avrami常数n值接近2,随着退火温度的变化,n值没有明显的变化,非晶晶化机理没有发生改变,而放热峰宽随着退火温度的降低明显宽化,说明非晶晶化过程是一个二维扩散控制的形核与长大过程.
To clarify the crystallization properties of Fe-based bulk amorphous alloy, this paper studied the crys- tallization kinetics of Fe45Co7Cr15Mo10Y2B6C15 bulk amorphous alloy prepared by copper-mold casting in the mode of continuous heating and isothermal annealing by differential scanning calorimetry (DSC)at 1 000 K. The results show that the crystalline phase is cementite after annealling at 973 K. The crystallization process with activation energy of 555.9 kJ/mol indicates that the amorphous alloy has good stability. Avrami n is close to 2 and changes little with the increasing of annealing temperature, which indicates that the crystallization mechanism doesn ' t change. The exothermic peak width increases when the annealing temperature decreases. Amorphous-to-crystallization transformation is a nucleation and growth process controlled by two-dimensional diffusion.
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