Copper and copper alloys are important industrial raw materials. They are widely used in the power electronics industry due to their good electrical conductivity. However, sometimes, the low strength of copper also limits its application in certain occasions. Therefore, how to improve its strength while maintaining its good electrical conductivity has become an important topic.
Recently, the research group of Professor Jia Lei of Xi’an University of Technology proposed to use of a vibrating mixing device to evenly mix CrB2 ceramic powder into copper powder. Use the FAST (Field-assisted Sintering Technology) to prepare a dense composite blank. Finally, make it into a rod by hot extrusion. The results showed that when the ceramic phase addition was only 3%, the tensile strength was increased to 304MPa, the elongation at break was 22%, and the electrical conductivity could be maintained at 90%IACS. This achieved the optimization of the comprehensive performance of the composite material. The article was published in the Journal of Materials Research and Technology.
The preparation technology route of copper matrix composites is as follows:
Here, use a vibrating mixing device for powder mixing. The experimental results show that this mixing method is superior to traditional ball milling in terms of experimental efficiency and powder mixing uniformity, and introduces fewer impurities. After only two hours of mixing operation, the ceramic powder can be evenly distributed on the copper powder. This result was confirmed by the scanning electron microscope photos.
Sintering of copper matrix composites using FAST field-assisted sintering technology furnace
The mixed powder is then loaded into a graphite mold and sintered in our CNE-FHP-828 FAST Field-assisted Sintering Technology Furnace. The heating rate is 100℃/min, then reduced to 20℃/min before approaching the insulation temperature, and set the pressure to 40MPa. A series of experiments show that the FAST Furnace can accurately control temperature and pressure, effectively ensuring the accuracy and consistency of the sintering process. Subsequently, the blank is used for the next hot extrusion experiment.
A series of experimental results show that 3% CrB2 addition is the best for improving strength, and more will reduce the strength. Based on theoretical analysis, the article proposes an optimized composition and process and provides a feasible solution for balancing the strength and electrical conductivity of copper materials.
