氮化铝基导热复合材料的制备及性能

Preparation and Properties of AlN-Based Thermal Conductive Composites

以AlN角形粉和AlN球形粉为填料,以PDMS为有机基体,制备不同固含量的导热复合材料,研究了AlN形态、AlN填充分数及粉体表面改性等对导热复合材料粘度及热导率的影响。研究结果表明,与角形AlN粉体相比,球形AlN粉体可显著降低复合材料的粘度,因而有利于获得更高的填充分数和更大的复合热导率。利用KH570对AlN粉体进行表面改性,有利于降低界面热阻,提高复合热导率,改性浓度(质量分数)为2.0%时,复合材料热导率可提高22.5%。

Thermal conductive composites with various filling fractions were prepared using angular and spherical AIN powders as fillers and PDMS as organic matrix.The influence of particle morphology,filling fraction and surface treatment on the viscosity and thermal conductivity of composites was deeply investigated.The results indicate that the AIN spherical powders can significantly reduce the viscosity of composites compared with the AIN angular powders,which is in favor of obtaining higher filling fraction and larger composite thermal conductivity.In addition,the surface treatment of AIN powders with KH570 is beneficial to reduce the interface thermal resistance and to improve the composite thermal conductivity.When the concentration of KH570 is 2.0 wt%,the highest composite thermal conductivity is obtained,which is -22.5% higher than that of untreated fillers.