Spark plasma sintering of Al2O3–Ni nanocomposites using Ni nanoparticles produced by rotary chemical vapour deposition

Al2O3–Ni nanocomposites were fabricated by spark plasma sintering (SPS) using Ni nanoparticle produced by rotary chemical vapour deposition. Carbon-free Ni nanoparticles were prepared by reacting NiCp2 with O2 to form NiO and then reducing to Ni by H2 for 30 min at 823 K. The highest Ni content and grain size were 7.8 wt.% and 47.7 nm, respectively, using a NiCp2 supply rate (Rs) of 1.67 × 10−6 kg s−1. At a sintering temperature (TSPS) of 1573 K, the hardness of Al2O3–3.8 wt.% Ni was 20.5 GPa, around 1 GPa higher than that of monolithic Al2O3 sintered at the same temperature. The tensile strength of Al2O3–4.6 wt.% Ni was 170 MPa, 60 MPa higher than that of Al2O3 sintered at 1573 K.