Processing and Characterization of Dense Thin Sheets of Gamma Titanium Aluminide
A powder metallurgy route based on hot isostatic pressing (HIPing) of tape-cast monotapes was used for the direct fabrication of dense thin sheets of gamma titanium aluminide. Gamma TiAl powder was tape-cast to form a sheet and inserted into a HIP can. In situ binder removal, followed by HIPing and decanning, produced a dense sheet (thickness = 250-300 μm). The carbon content of the sheet was only 0.035% higher than that of the starting powder but the oxygen content was significantly higher, presumably due to oxidation during decanning. The Vickers microindentation hardness was 384 ± 9 HV. The dense sheet consisted of a fine-grained, microstructure (average grain size ∼ 3 μm), with a few isolated larger grains (∼ 20 μm). Thermal annealing of the as-HIPed sheet at 1175-1375°C produced normal microstructures with limited grain growth, but effects attributable to oxidation were observed in a thin surface layer.
A. G. Adams et al., "Processing and Characterization of Dense Thin Sheets of Gamma Titanium Aluminide," Materials Science and Technology, Maney Publishing, Jan 2005.
Materials Science and Engineering
Keywords and Phrases
Gamma Titanium Aluminide; Hot Isostatic Pressing; Tape Casting; Thin Sheet
Article - Conference proceedings
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