挤压致密超细WC/纳米Al2O3弥散强化铜基复合材料的组织性能研究

以纳米Al₂O₃颗粒、超细WC粉末、工业纯Cu粉末为原料, 通过热挤压致密获得了超细WC/纳米Al₂O₃弥散强化铜基(WC-Al₂O₃/Cu)复合材料, 研究了挤压态WC-Al₂O₃/Cu复合材料的微观组织及力学性能。结果表明: 成分为5% WC-2% Al₂O₃/Cu和10% WC-2% Al₂O₃/Cu (质量分数)的两种原料粉末, 经机械球磨、冷压、真空烧结和热挤压后, 其相对密度均达到了99%以上, 超细WC和纳米Al₂O₃强化相颗粒呈均匀弥散分布, 具有很好的导电性及力学性能; 其中, 5% WC-2% Al₂O₃/Cu复合材料的综合性能更佳, 其抗拉强度达到235.06 MPa, 延伸率为15.47%, 导电率可达85.28% IACS, 软化温度不低于900℃。

Study on the microstructure and properties of dispersion-reinforced Cu-based composites by ultrafine WC and nano-sized Al2O3 particles via extrusion densification

The dispersion-reinforced Cu-based composites by ultrafine WC and nano-sized Al₂O₃ particles (WC-Al₂O₃/Cu)were obtained by hot extrusion densification using the nano-sized Al₂O₃ particles, ultrafine WC powders, and industrial pure copper powders as raw materials. The microstructures and performances of the extruded WC-Al₂O₃/Cu composites were investigated. In the results, the relative density of the 5%WC-2%Al₂O₃/Cu and 10%WC-2%Al₂O₃/Cu composites by mass is over99% after mechanical milling, cold pressing, vacuum sintering, and hot extrusion. At this meantime, the ultrafine WC and nano-sized Al₂O₃ particles distribute homogenously in the Cu matrix, resulting in high mechanical strength and excellent electrical conductivity. The tensile strength, elongation, and electrical conductivity of 5%WC-2%Al₂O₃/Cu composites are 235.06 MPa, 15.47%, and 85.28% IACS, respectively, and the softening temperature is above 900℃, showing a better comprehensive performances.