LAUSR

Abstract Transparent MgAl2O4 ceramics have been successfully fabricated by microwave sintering and hot isostatic pressing (HIP) from high purity spinel nanopowders. The influence of microwave sintering temperature on densification and microstructure was studied, choosing 1400 °C as the sintering temperature. The comparative study of microwave sintering and pressureless sintering of MgAl2O4 ceramics was made to investigate the difference between the two sintering methods. Compared to the conventional pressureless sintering, the microwave sintered MgAl2O4 ceramics reach relative high density at lower temperature and much shorter time. The in-line transmittance of the transparent 1.5 mm thick MgAl2O4 ceramic obtained by microwave sintering (1400 °C, 80 min) and HIP (1650 °C/180 MPa/3 h) was 86.4% at 1064 nm and 80.2% at 400 nm, respectively. The samples have a Vickers hardness of 13.7 GPa.