石墨表面TiC涂层对高定向石墨/Cu复合材料热导率和抗弯强度的影响

以高温盐浴法对天然鳞片石墨粉体(GF)进行表面TiC镀层处理,然后采用真空热压烧结法制备TiCGF/Cu复合材料,研究了粉体表面涂层和GF体积分数对复合材料微观结构、热导率及抗弯强度的影响。系列测试结果表明:随着GF体积分数的降低以及粉体表面TiC镀层的形成,TiC-GF/Cu复合材料平行于GF片层方向的热导率有所降低,抗弯强度有所提升。其中在GF的体积分数占TiC-GF/Cu复合材料70%时,这种变化最为明显,平行于GF片层方向的TiC-GF/Cu复合材料热导率下降幅度最大,从676W/(m·K)下降到526 W/(m·K)。同时,TiC-GF/Cu复合材料的微观结构进一步说明,GF表面的TiC涂层对GF/Cu复合材料的断裂模型起着重要的作用。

Effect of TiC coating on the thermal conductivity and flexural strength of graphite/Cu composites with preferred orientation

TiC layer was coated on the surface of the nature graphite flake (GF)by the molten salt method,and then GF/Cu composites were fabricated by vacuum hot-press sintering with TiC coated GF and Cu powder.The effects of volume fraction of GF and TiC coating on the thermal conductivity and flexural strength of the composites were investigated.A series of analysis results show that with the decrease of volume fraction of GF and the forma-tion of TiC layer,the thermal conductivity of TiC-GF/Cu composites decreases in the direction of the parallel graph-ite layer while the trend of flexural strength is increased.When the volume fraction of GF is 70% of TiC-GF/Cu composites,the thermal conductivity of TiC-GF/Cu composites along the plane parallel to the graphite laminate de-creases from 676 W/(m·K)to 526 W/(m·K),and the flexural strength of TiC coated GF/Cu composites is sig-nificantly enhanced from 52 MPa to 103 MPa.Meanwhile,microstructure features of TiC-GF/Cu composites further illustrate that TiC coated on the surface of GF plays an important role on the fracture model of GF/Cu composites.