高导热环氧/Al_(2)O_(3)复合材料制备工艺研究

Study on Preparation Technology of Epoxy/Al_(2)O_(3) Composite with High Thermal Conductivity

为控制环氧/Al_(2)O_(3)复合材料中Al_(2)O_(3)填料的沉降,通过对环氧复合物流变特性表征,深入研究预交联工艺与固化工艺对Al_(2)O_(3)填料沉降的影响机制。结果表明:适当延长预交联时间可以有效控制Al_(2)O_(3)填料沉降,同时固化工艺的预固化温度应与浇注温度匹配。采用最优工艺制备的环氧/Al_(2)O_(3)树脂复合材料结构及性能均匀,沉降率仅为0.5%,热导率为1.312 W/(m·K),同时具有优异的电气性能,其介电常数为4.94,介质损耗因数为0.002,体积电阻率为1.64×10^(19)Ω·m,电气强度约为33.38 kV/mm。

In order to control the settling of Al_(2)O_(3)filler in the epoxy/Al_(2)O_(3)composite,the influence mechanism of pre-crosslinking process and curing process on the settling of the Al_(2)O_(3)filler was studied by characterizing the rheological properties of the epoxy composite.The results show that properly prolonging the pre-crosslinking time can effectively control the settling of Al_(2)O_(3)filler,and the curing temperature of curing process should match the casting temperature.The epoxy/Al_(2)O_(3)composite prepared by the optimal process has uniform structure and performance,its settling rate is only 0.5%,thermal conductivity is 1.312 W/(m·K).Besides,the prepared epoxy composite has excellent electrical properties,the dielectric constant is 4.94,the dielectric loss factor is 0.002,the volume resistivity is 1.64×10^(19)Ω·m,and the electric strength is about 33.38 kV/mm.