CAJ | 학술논문

采用耦合流场的相场模型，模拟了强制流动作用下Fe-C合金等温凝固中的枝晶生长过程，研究了过冷度对枝晶生长行为的影响。结果表明：在纯扩散条件下，枝晶臂尖端为抛物线形，主枝根部有明显的二次分支。在强制流动作用下，逆流侧区域枝晶臂受过冷熔体冲刷，侧枝生长受到促进，形成发达二次枝晶；顺流侧区域富集大量溶质，不利于侧枝的形成和生长，无二次分支出现。随着过冷度的增加，逆流尖端生长速度和溶质摩尔分数均线性增加；顺流尖端生长速度二次函数增加，但顺流尖端的溶质摩尔分数先减小后增加。
채용우합류장적상장모형，모의료강제류동작용하Fe-C합금등온응고중적지정생장과정，연구료과랭도대지정생장행위적영향。결과표명：재순확산조건하，지정비첨단위포물선형，주지근부유명현적이차분지。재강제류동작용하，역류측구역지정비수과랭용체충쇄，측지생장수도촉진，형성발체이차지정；순류측구역부집대량용질，불리우측지적형성화생장，무이차분지출현。수착과랭도적증가，역류첨단생장속도화용질마이분수균선성증가；순류첨단생장속도이차함수증가，단순류첨단적용질마이분수선감소후증가。
The phase field model within coupling flow field has been used to simulate the dendrite growth process under forced flow during isothermal solidification of Fe-C alloy with research on effects of undercooling on the dendrite growth. The results have shown that the tip of dendrite arm was in shape of parabola and the secondary branches appeared at the root of main branches under the pure diffusion conditions. Under forced flow the undercooled melt flushing the dendrite arms in upstream side, which was advantageous to the growth of the side dendrite, the side-branches became developed secondary dendrites. The solute enriched in the downstream side, which was disadvantageous to the formation and growth of the side-branches, no secondary branches appeared on principal branch. With the increasing of undercooling, both the tip velocity and solute mole fraction of upstream dendrite increased linearly. And the growth velocity of tip of downstream dendrite increased in accordance with quadratic functional form but tip solute mole fraction decreased at first and then increased.