Synthesis and characterisation of Al2O3/Ni-type composites obtained by spark plasma sintering

This paper presents the influence of sintering on the structure, morphology and compressing strength of alumina/nickel composite compacts obtained by spark plasma sintering (SPS). Al2O3/Ni composites were prepared by SPS in argon atmosphere at temperatures in the range of 1000-1200 -C with a holding time of 2, 5 and 10 minutes. The heating rate was 200 C min(-1). These composites have been characterised by X-ray diffraction, SEM and EDX. The relative density and compressive strength of the as-obtained compacts were determined. The results showed that the alumina particles are uniformly dispersed in a quasi-continuous Ni network, and there was no sign of phase changes during sintering. The maximum strength of the alumina/nickel composite with a content of 75 vol. - Al2O3 and 25 vol. - Ni was about 240 MPa for the samples sintered at 1200 C for 10 minutes.