Grain growth kinetic of spark plasma sintered magnesia

In this research, the densification of magnesia nanopowder with a mean particle size of about 100 nm was investigated by spark plasma sintering undera pressures of 80 MPa and at temperature range from 1000 °C to 1400 °C and a heating rate of 50 °C/min for 20 minutes. The density of the samples slowly increased with increasing sintering temperatures to 1200 °C. Afterwards, with more increasing of temperature, decreasing density and increasing of grain growth were observed. Grain growth was analyzed during the sintering process with the classic grain growth theory. The results of the survey on the density showed that the highest densification rate occurred at 1100 ℃. The activation energy of grain growth was Obtained 452.24 kJ / mol. The MgO ceramic spark plasma sintered at 1200 °C for 20 min demonstrated the highest infrared transmittance of 67 % at the 5.6 μm wavelength.