Sinterability and characterization of Ag/Al2O3 metal and ceramic matrix composites processed by mechanical milling

Abstract

In this research, the sinterability of Ag/Al2O3 milled powders with 10 and 90 wt%Ag were investigated. The powders were consolidated by two different processes including conventional and spark plasma sintering. The conventionally sintered composites with 90 wt%Ag were further densified by cold pressing and subsequent annealing at 700°C. The microstructural evaluations confirmed a fine dispersion of the constituents within the microstructure of the spark plasma sintered composites. Moreover, the results showed that the relative density, hardness, and flexural strength of the spark plasma sintered samples were much higher than those of the other samples. The hardness and flexural strength of Ag/10 wt%Al2O3 spark plasma sintered samples at 650°C were 146 HV and 264 MPa, respectively. However, unlike the composite with 90 wt%Ag, the applied sintering temperatures have not led to the synthesis of an Ag/90 wt% Al2O3 composite with the desired properties

Keywords

• spark plasma sintering
• ag/al2o3 composites
• mechanical milling
• densification
• microstructure