EXPERIMENTAL RESEARCH ON HEAT TRANSFER PERFORMANCE OF DIRECTIOANLLY SOLIDIFIED POROUS COPPER HEAT SINK

Porous copper with long cylindrical pores has been fabricated by unidirectional solidification of metal-gas eutectic system, which can be used to manufacture a special kind of micro-channel heat sink. The heat transfer performance of the directionally solidified porous copper heat sink with a length of 20 mm along the axial direction of pores was studied. The experimental results show that the directionally solidified porous copper heat sink has excellent heat transfer performance and a heat transfer coefficient of 5 W/(cm(2).K) is attainable when a porosity is 29% and mean pore diameter is 400 mu m, and it shows a larger heat transfer coefficient of 6.5 W/(cm(2).K) after cutting the porous copper along the vertical direction of pore axis into two sections alined in the direction of pore axis. Increasing the length of porous copper heat sink along the direction of pore axis will reduce the penetration ratio of pores and then weaken the heat transfer performance of the heat sink. Thus some methods have to be taken to increase the pore length and ratio of penetrating pores when fabricating directionally solidified porous copper heat sink.