研究改性Si₃N₄掺量对氮化硅/聚碳酸酯（Si₃N₄/PC）复合材料的热学性能、绝缘性能和力学性能的影响。结果表明：Si₃N₄掺量较少时，Si₃N₄分布均匀；Si₃N₄掺量过大容易引起Si₃N₄聚集和不均匀分布。随着Si₃N₄掺量的增加，复合材料的热导率和热稳定性得到提高，体积电阻率和介电常数逐渐增大，拉伸强度、弯曲强度和冲击强度逐渐降低，压缩强度逐渐增大。Si₃N₄掺量较少时，热导率、热稳定性、绝缘性能和压缩强度增长较快，拉伸强度、弯曲强度和冲击强度降低较慢；Si₃N₄掺量较高时，热导率、绝缘性能和压缩强度增长变慢，拉伸强度、弯曲强度和冲击强度降低较快，热稳定性有所降低。Si₃N₄掺入质量分数为30%时，Si₃N₄/PC的综合性能较好，与纯PC相比，热导率提高538.9%，质量损失5%时的温度提高37 ℃，体积电阻率和介电常数提高179.6%和22.6%，拉伸强度、弯曲强度和冲击强度分别降低6.7%、5.0%和7.1%，压缩强度提高16.6%。

The study investigates the effects of the content of modified Si₃N₄ on the thermal properties, electrical insulation properties, and mechanical properties of silicon nitride/polycarbonate (Si₃N₄/PC) composites. The results show that when the content of Si₃N₄ is low, it is distributed uniformly. However, excessive Si₃N₄ content tends to cause aggregation and non-uniform distribution of Si₃N₄. As the Si₃N₄ content increases, the thermal conductivity and thermal stability of the composites are enhanced, while the volume resistivity and dielectric constant gradually increase. Meanwhile, the tensile strength, flexural strength, and impact strength decrease gradually, whereas the compressive strength increases. At low Si₃N₄ content, the thermal conductivity, thermal stability, electrical insulation, and compressive strength increase rapidly, while the tensile strength, flexural strength, and impact strength decrease slowly. At high Si₃N₄ content, the growth rate of thermal conductivity, electrical insulation, and compressive strength slows down, while the tensile strength, flexural strength, and impact strength decrease more rapidly, and the thermal stability is somewhat reduced. When the mass fraction of Si₃N₄ is 30%, the Si₃N₄/PC composites exhibit better comprehensive properties. Compared with pure PC, the thermal conductivity is increased by 538.9%, the temperature at which the mass loss reaches 5% is increased by 37 ℃, the volume resistivity and dielectric constant are increased by 179.6% and 22.6%, respectively. The tensile strength, flexural strength, and impact strength are reduced by 6.7%, 5.0%, and 7.1%, respectively, while the compressive strength is increased by 16.6%.