短碳纤维/铜复合材料的制备及其组织和性能

Preparation,microstructure and properties of SCF/copper composites

以电解铜粉、酚醛树脂包覆短碳纤维为原料,通过球磨混合,冷压成型及加压烧结工艺制备碳纤维分散均匀、结构可调控、性能良好、工艺简单、成本低的短碳纤维/铜复合材料。对比分析球磨2 h、3 h、4 h后短碳纤维在基体中的形貌及结构变化、均匀分布程度,短碳纤维/铜复合材料的显微组织及其物理和力学性能的差异。结果表明:在树脂对短碳纤维的分散和保护作用下,碳纤维在铜基体中的分散均匀性得到较大提高,碳纤维/铜复合材料内部碳/铜界面结合良好且基体均较为致密;随着球磨时间的延长,碳纤维只发生形貌及长度的变化而不发生结构改变,长度分布的均一化程度逐渐提高,碳纤维平均长度由32.28μm逐渐减小至23.65μm;短碳纤维/铜复合材料的表观密度、电导率、抗弯强度先增加后减小,开孔率随球磨时间的增加先减小后增大,硬度无明显变化。球磨分散3 h制备的短碳纤维/铜复合材料的综合物理和力学性能良好,其表观密度、开孔率、电导率、抗弯强度、硬度分别为7.93 g/cm3、4.53%、38.73 MS/m、332.94 MPa、46.17 HV。

Using electrolytic copper powder and phenolic resin-coated short carbon fiber as raw materials,the SCF/Cu composites with short carbon fiber uniform dispersed,controllable structure,good performance,simple process and low cost were prepared through ball mill mixing,cold pressing and pressure sintering.The morphology and structural changes,the uniform distribution degree of short carbon fiber in the matrix after ball milling for 2 h,3 h,and 4 h,as well as the differences in microstructure,physical and mechanical properties of the SCF/Cu composites were compared and analyzed.The results show that the dispersion uniformity of short carbon fiber in copper matrix is greatly improved under the effect of phenolic resin on dispersion and protection of short carbon fiber,the carbon/copper interface is well bonded and the matrix is dense in the SCF/Cu composites.With the increase of ball milling time,only the morphology and length of short carbon fiber change without structural change.The uniformity of length distribution gradually increase,and the average length of the short carbon fiber gradually decrease from 32.28μm to 23.65μm.The apparent density,electrical conductivity and flexural strength of the SCF/Cu composites increase first and then decrease,the open porosity decreases first and then increases,and the hardness does not change significantly.The comprehensive physical and mechanical properties of the SCF/Cu composites prepared by ball milling for 3 h are good,with apparent density,porosity,electrical conductivity,bending strength and hardness of 7.93 g/cm3,4.53%,38.73 MS/m,332.94 MPa and 46.17 HV,respectively.