横向约束对Fe-C合金凝固微观组织的相场法模拟

以Fe-C二元合金为例,采用多相场法模拟了横向约束条件下枝晶与共析组织微观形貌的演化过程,探讨了横向约束的长度、厚度对枝晶与共析组织生长形貌的影响.结果表明:横向约束的存在限制了枝晶和共析组织的正常生长,横向约束上方的微观组织形貌明显改变;随着横向约束长度的增加,横向约束上方的枝晶间距明显减小,共析组织的层间距越来越大;随着横向约束厚度的增加,横向约束上方新枝晶的生长速度降低,共析组织中Fe₃C相偏转增大,使得层间距变大.

Simulation of phase field method for solidification microstructure of Fe-C alloy by lateral constraint

Taking Fe-C binary alloy as an example, the evolution process of dendrite and eutectoid microstructure under transverse restraint was simulated in this study by adopting the multiphase field method. The influence of length and thickness of transverse restraint on growth morphology of dendrite and that of eutectoid microstructure was discussed in terms of simulated microstructures. All results coming from our simulation indicate:The normal growth of dendrite and eutectoid is limited by the existence of transverse constraint, and the morphology of microstructure above the transverse constraint changes obviously; With the increase of the length of transverse constraint, the dendrite spacing above the transverse constraint decreases obviously, and the layer spacing of the eutectoid structure becomes larger as a result;With the increase of transverse constraint thickness, the growth rate of new dendrites above transverse constraints decreases, and the deflection of Fe₃C phase in eutectoid structure increases, resulting in larger interlayer spacing.