Microstructures and Properties of 0.3%Y2O3/0.3%La2O3/0.3%Al2O3/Cu Composite Treated by Annealing

The 0.3%Y2O3/0.3%La2O3/0.3%Al2O3/Cu composite was prepared by oxygen and nitrogen atomization spray deposition technique, internal oxidation and then treated by annealing at different temperatures. The microstructures, fracture appearance, hardness, strength, electrical conductivity and arc erosion surface of the composite were investigated. The results show that with the increasing of the annealing temperature, the grains of the composite grow up obviously and the electrical conductivity of the composite increases gradually, while the hardness and the tensile strength decrease. When the annealing temperature reaches to 1000 degrees C, annealing twins begin to appear in the matrix grains. The tensile fracture morphology of the composite treated by annealing at 700 degrees C for 2 h shows a great number of large and deep dimples, in which the metallic oxide particles exist. The fracture mode of the composite is the microporous polycondensation plastic fracture. The arc erosion surface shows a large number of paste-like coagulum and bubbles.