Structure formation in 〈001〉 single crystals of a nickel-based superalloy solidified with TiCN powder addition

The solidification structure and tensile properties of single crystals of nickel-based superalloy have been examined as influenced by additions of ultra dispersed powder of titanium carbonitride to the melt before solidification. Two variants of alloy (carbon-containing and low carbon) were studied. The addition has been found to change the morphology and chemical composition of the carbide phase in the carbon-containing alloy and to affect the dissolution of the strengthening γ′-phase in the low carbon alloy. Solidification with addition leads to an increase of creep-rupture life of single crystal samples, especially for the low carbon variant.