Distinctive features of diffusion-controlled radiation defect recombination in stoichiometric magnesium aluminate spinel single crystals and transparent polycrystalline ceramics

Evaluation of IKTS Transparent Polycrystalline Magnesium Aluminate Spinel (MgAl2O4) for Armor and Infrared Dome/Window Applications

In-situ Fabrication of Transparent Magnesium Aluminate Spinel by Spark Plasma Sintering

Transparent polycrystalline spinel ceramic was fabricated without any sintering aids by spark plasma sintering method of a mixture of Al2O3 and MgO powders for only 10min soak at 1250°C. Densification, microstructure and optical transparency of spinel were examined. The spinel exhibits an in-line transmission of 55% for a visible-wavelength of 470nm and high hardness value of 2040 HV.

Creep of Polycrystalline Magnesium Aluminate Spinel Studied by an SPS Apparatus

A spark plasma sintering (SPS) apparatus was used for the first time as an analytical testing tool for studying creep in ceramics at elevated temperatures. Compression creep experiments on a fine-grained (250 nm) polycrystalline magnesium aluminate spinel were successfully performed in the 1100-1200 °C temperature range, under an applied stress of 120-200 MPa. It was found that the stress expon...

The Effect of Lithium Doping on the Sintering and Grain Growth of SPS-Processed, Non-Stoichiometric Magnesium Aluminate Spinel

The effects of lithium doping on the sintering and grain growth of non-stoichiometric nano-sized magnesium aluminate spinel were studied using a spark plasma sintering (SPS) apparatus. Li-doped nano-MgO·nAl₂O₃ spinel (n = 1.06 and 1.21) powders containing 0, 0.20, 0.50 or 1.00 at. % Li were synthesized by the solution combustion method and dense specimens were processed using a SPS apparatus at...

Hydrogen and deuterium diffusion in non-stoichiometric spinel

High pressure/temperature annealing experiments are used to determine diffusivities of H and D in non-stoichiometric spinel, a low-pressure analogue for nominally anhydrous minerals in Earth’s mantle. Data are fitted to the following Arrhenius law: Diffusivity (m/s) = 4 ± 1 × 10 exp(−54 ± 2 kJ mol/RT). At low temperatures, H and D diffusion in non-stoichiometric spinel is charge balanced by flu...