Al2O3含量对放电等离子烧结Al2O3/Cu复合材料组织与性能的影响

以微米级Cu粉为基体相,纳米Al₂O₃颗粒为绝缘相,采用机械球磨和放电等离子烧结工艺相结合的方法制备Al₂O₃/Cu复合材料,研究Al₂O₃含量对复合材料微观结构、电阻率和热导率的影响。结果表明,Al₂O₃/Cu复合材料为核?壳结构,随Al₂O₃含量增加,Al₂O₃包覆层对Cu基体的包覆效果逐渐提升;当w(Al₂O₃)为5%时,Al₂O₃/Cu复合材料的热导率较高,为85.92 W/(m·K),但电阻率偏低,仅为12.6 mΩ·cm。当w(Al₂O₃)增加至15%时,虽然Al₂O₃/Cu复合材料的密度降至6.69 g/cm³,孔隙率较高,但电阻率显著提高至2.09×10⁸ mΩ·cm,约为Cu电阻率的10¹¹倍,且热导率为7.6 W/(m·K),明显高于传统金属基板的热导率。

Effects of Al2O3 content on microstructure and properties of Al2O3/Cu composite materials prepared by spark plasma sintering

Al₂O₃/Cu composite materials,with micron Cu powders as matrix phase and nano Al₂O₃ particles as insulating phase were prepared by mechanical ball milling combined with spark plasma sintering.The effects of Al₂O₃ content on the microstructure,resistivity and thermal conductivity of the Al₂O₃/Cu composite materials were investigated.The results show that the Al₂O₃/Cu composite materials are core-shell structure.With the increase of Al₂O₃ content,the covering effect of the Al₂O₃ coating on the copper substrate is gradually enhanced.When w(Al₂O₃)is 5%,the thermal conductivity of the Al₂O₃/Cu composites is relatively high,which is 85.92 W/(m·K),but the resistivity is relatively low(12.6 mΩ·cm).When w(Al₂O₃)increases to 15%,the density of the Al₂O₃/Cu composites decreases to 6.69 g/cm³ and the porosity is higher.But the resistivity significantly increases to 2.09×10⁸ mΩ·cm,which is about 10¹¹ times of Cu and the thermal conductivity is 7.6 W/(m·K),which is obviously higher than that of the traditional metal substrate.