Abstract
In this study, we used formaldehyde as reducing agent and sodium bicarbonate as foaming agent, to successfully synthesize nanosized silver materials at 85℃ with porous structure composed of aggregated particles whose mean size was about 60nm. These porous silver materials were subsequently applied as capillary structure in a copper heat pipe. The morphology and composition of these materials were characterized by SEM and XRD. The porous silver material was pressed by a model to make an Ag packing film, and subsequently measured the changes of porosity and permeability of that after heat treatment with different temperatures. Finally these materials were applied in a heat pipe to study the effect, e.g. water content, porosity, packing thickness, pore size distribution as well as different kinds of working fluids, on the heat resistance of the heat pipe. With an Ag packing film, 90mm x 25mm x 0.5mm in size, porosity 80% and pore size 515nm, one could get the lowest heat resistance 0.86[℃/W] of heat pipe at working power 60W while water was used as working fluid.