Effect of Y2O3 crucible on contamination of directionally solidified intermetallic Ti–46Al–8Nb alloy

Grain refinement in beta-solidifying Ti44Al8Nb1B

“…The oxygen content in the Bridgman specimens was not measured since the contamination by the yttria crucible would render the measurement less meaningful. Details about yttria crucible contamination can be found elsewhere [11]. The Bridgman specimens were sliced longitudinally and the microstructures were analysed using scanning electron microscopy (SEM) and electron backscattering diffraction (EBSD).…”

High temperature deformation behaviors of polysynthetically twinned (PST) Ti–47Al–2Cr–2Nb alloy

“…TiAl-based alloys have received considerable attention during the past few years as potential candidates for turbine and combustion engines applications due to their high strength-todensity ratios combined with a reasonable oxidation resistance at elevated temperature near 800 1C [1][2][3][4][5]. Especially, TiAl-based alloys with fully lamellar microstructure show superior mechanical properties (high-temperature strength, room-temperature toughness) to other types of microstructures such as near gamma, duplex and nearly lamellar types [6,7].…”

Preparation of TiAl-based alloys by induction melting in graphite crucibles

“…Density and open porosity of commercially available cold isostatic pressed graphite crucibles for induction melting with a diameter of 66 mm/74 mm (inside/outside diameter) and length of 135 mm were measured using Archimedes principle, as described previously by Lapin et al [13]. The crucible density (ρ m ), volume fraction of open porosity (P o ) and densification of crucible D m were calculated according to following equations:…”

“…Among various processing techniques, precise casting offers the most cost effective method for production of complex shaped components from TiAl-based alloys [4,5]. Until now, no refractory material was found to be absolutely inert against these alloys and some interactions between melted alloy and crucible and mould materials always occurred during melting and casting [7][8][9][10][11][12][13][14][15][16][17]. These melt-ceramic material interactions lead to contamination and to degradation of some mechanical properties of cast components [10,11].…”