Hydrogen permeability of ' gh-density, high-purity sintered alumina tubes was measurh 1s a function of temperature and pressure using tritium as a tracer. The permeability, 4, at 1200" to 1450°C and hydrogen partial pressure between 2 and 50 kPa is:(H atoms cm cm12 s-' kPa-o."J ) = exp(48.95?0.61) exp[ -318.22 18.8 kJ(g.atom)-' (RT)-'] Diffusion coefficients and solubility values deduced from the permeation experiments are consistent with earlier independent measurements. No accelerated permeation due to microstructural defects or changes during the experiments was observed. Comparison of hydrogen permeability of alumina with the values observed for metals shows that alumina may be a suitable coating material for use as a hydrogen permeation barrier.

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