Near-net-shaped (Ba,Sr)Al2Si2O8 bodies by the oxidation of machinable metal-bearing precursors

A novel process has been used to fabricate refractory aluminosilicate bodie s of near net shape: the oxidation of machinable, alkaline-earth-metal-bear ing precursors. Ba-Sr-Al-Al2O3-SiO2 precursors of similar molar volume as s trontium-doped celsian, (Ba,Sr)Al2Si2O8, were prepared by powder metallurgi cal processing. Precursor powder mixtures, obtained by high-energy vibrator y ball milling, were compacted and formed into bars or disks by uniaxial pr essing. The bar-shaped precursors were machined on a metal-working lathe us ing hardened steel tooling, The shaped precursors were oxidized and convert ed into celsian, The resulting celsian bodies retained the shapes, and fine machined features, of the precursors. The measured changes in dimensions w ere small and in good agreement with calculated values.