太原科技大学学报
太原科技大學學報
태원과기대학학보
JOURNAL OF TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
2015年
2期
160-164
,共5页
枝晶生长%相场模型%有限差分法
枝晶生長%相場模型%有限差分法
지정생장%상장모형%유한차분법
dendritic growth%phase-field method%finite difference method
采用相场方法对金属枝晶的生长过程进行数值模拟。用凝固相场方程描述过冷条件下枝晶生长的物理过程,同时在相场方程中耦合温度场方程以体现凝固过程中释放的潜热对相变的影响。采用有限差分法进行求解,讨论了松弛时间、方向角、界面宽度、熔点、各向异性、潜热等因素对枝晶的形状和生长的影响。结果表明,随着松弛时间、界面宽度和熔点的逐渐增加,晶体的生长速率也在逐渐增加,并且枝晶越来越发达。
採用相場方法對金屬枝晶的生長過程進行數值模擬。用凝固相場方程描述過冷條件下枝晶生長的物理過程,同時在相場方程中耦閤溫度場方程以體現凝固過程中釋放的潛熱對相變的影響。採用有限差分法進行求解,討論瞭鬆弛時間、方嚮角、界麵寬度、鎔點、各嚮異性、潛熱等因素對枝晶的形狀和生長的影響。結果錶明,隨著鬆弛時間、界麵寬度和鎔點的逐漸增加,晶體的生長速率也在逐漸增加,併且枝晶越來越髮達。
채용상장방법대금속지정적생장과정진행수치모의。용응고상장방정묘술과랭조건하지정생장적물리과정,동시재상장방정중우합온도장방정이체현응고과정중석방적잠열대상변적영향。채용유한차분법진행구해,토론료송이시간、방향각、계면관도、용점、각향이성、잠열등인소대지정적형상화생장적영향。결과표명,수착송이시간、계면관도화용점적축점증가,정체적생장속솔야재축점증가,병차지정월래월발체。
The growth of metal dendritic crystal is simulated numerically by using phase field method. The phase-field equation of solidification is used to describe the physical process of dendritic growth under the condition of un-dercooling. Meanwhile,the temperature evolution equation is coupled into phase-field equation to reflect the influ-ence of the latent heat released during the process of solidification on phase change. The finite difference method is used to solve the phase-field and temperature equations. The evolution and shapes of dendrites under different con-ditions are given. The influences of the parameters,such as relaxation time,orientation angle,interfacial width,melt-ing temperature,interface anisotropy and latent heat,on the growth and shape of dendrite,are discussed in detail. Numerical results show that the growth rate of crystal increases gradually,and the dendrites will be fully developed as the values of relaxation time,the interface width and the melting point increase.