Powder Technology, Vol.343, 705-713, 2019
Properties and microstructure of copper/nickel-iron-coated graphite composites prepared by electroless plating and spark plasma sintering
In order to improve the interfacial bonding between copper and graphite, the quasi-spherical graphite powders were coated with nickel-iron alloy and copper in sequence by electroless plating. Copper/nickel-iron-coated graphite composites (graphite content: 80 vol%) were successfully prepared by spark plasma sintering (SPS). For comparison, copper/graphite composites with graphite content of 80 vol% were prepared by the same process. The microstructure, mechanical, electrical and wear properties of copper/nickel-iron-coated graphite composites were compared with those of copper/graphite composites. The results indicated that the introduction of nickel-iron coating obviously improved the wettability between copper and graphite due to the formation of carbides (Fe3C), borides (FeB, Fe3B and Ni3B) and solid solution. The metal phases in copper/nickel-iron-coated graphite composites were distributed uniformly and formed an excellent interconnected network. Compared with copper/graphite composites, the as-fabricated copper/nickel-iron-coated graphite composites showed better mechanical and wear-resisting properties, especially the bending strength increased from 42 MPa to 73 MPa, and did less damage to the pure copper counterpart ring. (C) 2018 Elsevier B.V. All rights reserved.
Keywords:Copper/nickel-iron-coated graphite composites;Electroless plating;Spark plasma sintering;Microstructure;Properties