原位反应制备陶瓷基复合相变材料及其工艺研究

Preparation and Technology of Ceramic-based Composite Phase ChangeMaterials by In-situ Reaction

针对熔融盐相变材料成型难、导热低的问题,设计采用微米级氮化铝原位反应的方法制备陶瓷基导热骨架,以此来吸附熔融盐,形成陶瓷基复合相变材料。研究了加水量及成型压力对该复合相变材料的性能影响,确定了最佳加水量为15%,最佳成型压力为30 MPa。分析SEM照片发现,原位反应生成的水解氧化铝具有花簇状结构,能够吸附复合盐,维持结构不塌陷。TG-DSC及导热测试表明,该复合相变材料具有182.4 J/g的相变焓和4.928 W/(m·K)的导热系数。在50次循环后,复合相变材料焓值几乎无衰减,具有很好的循环稳定性,其优异的性能归因于原位反应生成的陶瓷基导热骨架。

In order to solve the problem of difficult forming and low heat conduction of molten salt phase change materials,a method of in-situ reaction of micron aluminum nitride was designed to fabricate ceramic-based thermal conduction framework,which can absorb molten salt and form the ceramic-based composite phase change materials(CPCMs).The effects of water content and forming pressure on the properties of CPCMs were studied,which shows the optimum water addition of 15%,the best molding pressure of 30 MPa.Hydrolytic alumina(h-Al 2O 3)formed by in-situ reaction is found a flower like structure in SEM photos,which can absorb composite salts and maintain the structure without collapse.TG-DSC and thermal conductivity tests illustrate that the CPCMs have a 182.4 J/g phase change enthalpy and a 4.928 W/(m·K)thermal conductivity.After 50 cycles,there is almost no attenuation on the enthalpy of CPCMs,which possess good cycle stability.Their excellent properties are attri-buted to the ceramic-based thermal conduction framework formed by in-situ reaction.