Effect of CaO on the densification and mechanical properties of 17Ni/(10NiO-NiFe₂O₄) cermets

17Ni/(10NiO-NiFe₂O₄) cermets added with CaO were fabricated by cold pressing-sintering. The effects of CaO content and sintering temperature on the phase composition, relative density and mechanical properties of 17Ni/(10NiO-NiFe₂O₄) cermets were studied. The results show that the cermets consist of Ni, NiO and NiFe₂O₄. Introduction of CaO can accelerate the densification of 10NiO-NiFe₂O₄ composites. As the sintering temperature is limited at 1250℃, the relative density will achieve the maximum value of 98.75% for the sample doped 1.0wt% CaO, and then decrease with increasing the CaO content sequentially. With the temperature increasing from 1250℃ to 1350℃, the relative densities reveal the increase for the samples containing CaO with the content less than 0.5wt% and the decrease for the samples containing more than 0.5wt% CaO. Both increasing sintering temperature and adding CaO cause grow-up of the ceramic grain. An optimal bending strength value of 150.66MPa of the sample sintered at 1250℃, is achieved at the CaO content of 1.0%.