潜热及各向异性对凝固组织形貌的影响

Influence of Latent Heat and Anisotropy on Morphology of Solidified Structure

采用相场法研究了潜热及各向异性对微观组织凝固形貌的影响。结果表明:无量纲潜热在0.8~2.0范围内取值越大,晶粒生长的形貌越规则,越能突出主分支的生长优势,抑制二次枝晶的生长。各向异性强度在0.00~0.06范围内取值较小时,各分支大小趋于一致,无法分辨主侧支。各向异性强度越大,主分支的生长优势越明显。两者同时增加时,主分支生长优势逐渐凸显,变得细长,侧支逐渐弱化。在两者中,一个增另一个减时,枝晶形貌取决于相对较弱的一方。

The effect of latent heat and anisotropy on the microstructure solidification morphology was studied by phase field method. The results reveal that the larger the value of the dimensionless latent heat in the range of 0.8-2.0, the more regular the morphology of the grain growth, the more prominent the growth advantage of the main branch, which inhibits the growth of secondary dendrites. When the anisotropic strength is small in the range of 0.00-0.06, the size of each branch tends to be the same, and the main side branch cannot be distinguished. The bigger the anisotropic intensity, the more obvious the growth advantage of the main branch. When the both increase at the same time, the growth advantage of gradually becomes prominent, the main branch becomes slender, and the side branches gradually weaken. When the one increases and the other decreases,the dendrite morphology depends on the relatively weaker side.