摘要
对定向凝固多孔Cu热沉的传热性能进行理论分析和预测,并将定向凝固多孔Cu热沉传热性能的理论预测结果与实验结果进行了比较.结果表明,将定向凝固多孔Cu热沉单元进行肋片等效,由于实际热沉所用多孔Cu结构与其理想结构存在偏差,理论预测结果远高于实验结果;引入通孔率和通孔孔径对理论预测结果进行修正后,理论预测结果与实验结果吻合.定向凝固多孔Cu的结构是影响热沉传热性能的根本因素,根据理论分析,沿孔长方向长度为20 mm时,具有优异传热性能的热沉的定向多孔Cu部分应具有如下结构:孔径0.1—0.6 mm;气孔率30%—70%;高度≥4 mm.
Porous copper with long cylindrical pores fabricated by unidirectional solidification of metal-gas eutectic system can be used to manufacture a special kind of micro-channel heat sink. In order to simplify the heat transfer analysis, a fin model was introduced into the theoretical study on heat transfer performance of directionally solidified porous copper heat sink. The heat transfer performance of porous copper heat sink was also tested by experiments, and it was found that experimental values are far less than theoretical predicted ones. That is because the structure of porous copper might deviate from its ideal structure, such as, some pores are not penetrated, and the distribution of pore size and pore location is not uniform. After the model was modified by introducing area ratio of penetrating pores and mean diameter of penetrating pores, the theoretical results were consistent with the experimental results. Thus the analytical method based on the fin model in this paper can be used to predict the heat transfer performance of directionally solidified porous copper heat sink. According to the theoretical analysis, porous copper used for heat sink with excellent heat transfer performance should have the following porous structure： the pore diameter is 0.1--0.6 mm, the porosity is 30%-- 70%, the height of porous copper is more than 4 mm when its length along the direction of pore axis is 20 mm.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期1374-1380,共7页
Acta Metallurgica Sinica
基金
国家自然科学基金项目U0837603和51101092资助~~
关键词
热沉
微通道冷却
多孔金属
金属-气体共晶
定向凝固
heat sink, micro-channel cooling, porous metal, metal-gas eutectic, directional solidification
