Synthesis and Consolidation of Ag/ZnO Composite Powders via SPS Method

The present research was conducted to synthesize and densify Ag/8wt.% ZnO composites via co-precipitation and spark plasma sintering (SPS) methods. The initial precipitates were precipitated by adding ammonium hydrogen carbonate solution to a solution mixture of silver and zinc nitrate. The precipitates were characterized by using the particle size analyzer and X-ray diffraction techniques. The precipitates were calcined at 500°C and consolidated with SPS method for 5 and 10 min at 540°C under 35 MPa in vacuum. The results showed that rearrangement and bulk deformation had a significant effect on densification of the composite powders. The scanning electron microscopy investigations revealed that the SPSed composites had nearly dense microstructures with homogenous and fine dispersion of ZnO particles within the silver matrix. Moreover, it was confirmed that prolonging the sintering time from 5 to 10 min had no significant effect on the microstructure, relative density and hardness of the samples. Composites with relative densities above 99% and 62 HV hardness were synthesized through the applied procedure.