IR-transparent MgO-Gd2O3 composite ceramics produced by self-propagating high-temperature synthesis and spark plasma sintering
Д. А. Пермин, М. С. Болдин, Alexander Belyaev, Stanislav Balabanov, В. А. Кошкин, Atrem A. Murashov, И. В. Ладенков, Е. А. Ланцев, К. Е. Сметанина, Nadia M. Khamaletdinova
Abstract
Abstract A glycine-nitrate self-propagating high-temperature synthesis (SHS) was developed to produce composite MgO-Gd 2 O 3 nanopowders. The X-ray powder diffraction (XRD) analysis confirmed the SHS-product consists of cubic MgO and Gd 2 O 3 phases with nanometer crystallite size and retains this structure after annealing at temperatures up to 1200 °C. Near full dense high IR-transparent composite ceramics were fabricated by spark plasma sintering (SPS) at 1140 °C and 60 MPa. The in-line transmittance of 1 mm thick MgO-Gd 2 O 3 ceramics exceeded 70% in the range of 4–5 mm and reached a maximum of 77% at a wavelength of 5.3 mm. The measured microhardness HV0.5 of the MgO-Gd 2 O 3 ceramics is 9.5±0.4 GPa, while the fracture toughness ( K IC ) amounted to 2.0±0.5 MPa·m 1/2 . These characteristics demonstrate that obtained composite MgO-Gd 2 O 3 ceramic is a promising material for protective infra-red (IR) windows.