Preparation Of Porous Aluminum And Application In Heat Pipe

Owing to the porous aluminum has some merits, such as lower density, with the large specific surface area, high thermal conductivity, high capacity cooling heat exchanger, good permeability, excellent machinability and cheap, it become the research hot spot of heat exchange materials, and play important role especially the application of heat pipes. The diameter controllable porous aluminum was prepared with the spark plasma sintering (SPS).First, the diameter controllable particles were prepared via the antisolvent crystallization method, the smallest particles reach several microns. Other additives were added into the alcohol to decrease salt solubility in the preparation NaCl particles process by the antisolvent crystallization method, saturation is the key factor in the antisolvent crystallization method. When the alcohol as a single organic solvents, the mixing time is longer, the NaCl grain size is larger. The acidic solution causes reunion of particles, the basic solution causes larger particle size distribution and more gaps, smaller particle size distribution and more regular cube salt particles were prepared using neutral organic additives as an antisolvent, the amount of organic amendments affects the salt particle size, but it is littler effect on the morphology. The neutral organic solvents as additives were chosen to control the morphology of NaCl particles.Secondly, the different particle size of NaCl were chosen as porecreating matter to prepare low weight fraction NaCl/Al composite materials, sintering temperature, sintering pressure, heating rate were discussed by the SPS, preparing NaCl/Al composite materials by the SPS is feasible. Effect of sintering temperature, sintering pressure and the content and size of NaCl were discussed on the porous aluminum porosity and pore structure to receive the best sintering parameters. The results is shown that the porosity of NaCl/Al composite materials reach 69.41% through sintering the 60% sodium chloride mixed powder under 15MPa and 590℃, the smallest aperture is about 5μm, the average pore size is around 20μm.Third, the associative property of the porous layer and the combination of aluminum alloy plate of 60wt%NaCl+40wt%Al+aluminum alloy block (average 20μm NaCl and the prepressure 20MPa) is well under 25℃-50℃/2min -80℃/1min -130℃/1min-400℃/4min-515℃/4min-560℃/4min-568℃/2min-570°C/5min,the porosity of porous layer is 69% and the average pore size is 20μm.Finally, the sintered hot plate was applied to the ourselves designed flat heat pipe, the sintered porous layer basically meets the requirements of heat device, heat transfer is stabler.