Interfacial reaction and tensile properties of 6061Al matrix composite reinforced with copper-coated Al₁₈B₄O₃₃ whiskers

Copper was deposited onto the surfaces of aluminum borate whiskers through electroless plating. The microstructure and tensile strength of aluminum alloy 6061(AA6061) matrix composite reinforced by the copper-coated whisker were studied. The composite with a whisker volume fraction of 20% was fabricated by the squeeze casting method. The results show the interfacial reaction takes place only between the coating and matrix, and the ultimate tensile strength (UTS) of the composite is enhanced greatly by the whisker coating. When the composite was subjected to solution treatment at 490°C, the UTS of composite increases with the solution time increasing, and the UTS of the composite is 357 MPa when the solution time is 4 h. The mechanism of the effect of solution treatment on the tensile properties of the composite was discussed.