Microstructures and Mechanical Properties of Spark Plasma Sintered Al_2O_3-Co Composites Using Electroless Deposited Al_2O_3-Co Powders

摘要

Microstructures and mechanical properties of spark plasma sintered (SPS) Al_2O_3-Co composites were investigated depending on the sintering temperatures (900-1200 deg C) and cobalt contents (0 approx 12 mass percent). The material properties of relative density and fracture toughness increased as the sintering temperature and Co content (up to 12 mass percent Co) increased. In the SPSed Al_2O_3-Co composite sintered at 1200 deg C, maximum values of relative density and fracture toughness about 99.3 percent and 8.1 MPam~(1/2), respectively were obtained. The fracture morphology of SPSed Al_2O_3-12mass percentCo composite showed a semi-brittle fracture mode due to the homogeneous dispersion of fine-sized Co particles.