Study On Cr₂O₃/Cu Composite And Its Microstructure And Properties Prepared By Pre-oxidation Technique

The feasibility of copper matrix reinforced by Cr2O3 particles was discussed from the aspect of the demand of composite on reinforcer, interface and its formation. CrCu alloy powders prepared by water atomization were turned into Cr2O3/Cu compound powders, which were made into composites. The thermodynamics conditions of oxidation and deoxidation of CrCu powders were studied. The microstructure and properties were discussed in the end. The results show that:1 .The Cr2O3 particle is able to reinforce copper matrix and the pre-oxidation technique is feasible in preparing Cr2O3/Cu composite.2.The atomized CrCu alloy powders can be oxidized in the air and the oxides are Cr2O3, Cu2O and CuO.3.Cu2O and CuO are deoxidized into Cu when the oxidized powders are kept at 1073K for 30min in gas protected furnace, in which graphite is used for heating unit, while Cr2O3 can not be deoxidated. So the oxidized powders can be made into Cr2O3/Cu compound powders.4.The electrical conductivity of the forged composite which is made from oxidized alloy powders with the content of Cr 1.0wt% is 40.2 ml ( Q ?mm2) , and its hardness is 110HB. With the increasing of the content of Cr2O3 in composite, the electrical conductivityIIIABSTRACTdecreases and its hardness grows.S.The composite prepared has excellent heat stability and high-temperature property. During the course of high temperature annealing, the hardness of the composite does not reduce obviously until 973K, while the temperature of pure copper (after cold machining) is 423K in the same conditions.6.The Cr2O3 particles in Cr2O3/Cu composite prepared by pre-oxidization technique are as small as 200nm.