NEW PROCESSING FOR PREPARING Al₂O₃/Cu COMPOSITE BY IN SITU REACTION

A Cu-Al₂O₃(1.5wt% or so) composite was successfully prepared by using a new approach, which includes high energy milling of Cu and Al powder to produce Cu-Al alloy powder, high energy milling of the Cu-Al alloy powder together with Cu₂O powder, and preparing Al₂O₃/Cu composite through conducting oxidation and sintering synchronously in vacuum. The peculiarities of this approach are that the reduction of superfluous Cu₂O is left out, and the period of reacting and sintering is only 1 hour. It was observed that the Al₂O₃ particles uniformly dispersed in the copper matrix with an average size of 250nm in diameter and particles space between 500 nm. The properties of Al₂O₃/Cu composite are close to those of SCM products after cold working. The Al₂O₃/Cu composite possesses excellent thermal stability since there are no cracks observed after exposing to 800℃ and then cold quenching, which is cycled 20 times. The intenerating temperature of Al₂O₃/Cu composite is about 700℃.