Rare-earth metals (REMs) in nickel aluminide-based alloys: II. Effect of a REM on the phase composition of a multicomponent Ni3Al-based alloy

Effects of Y and La Additions on the Processing and Properties of a Second Generation Single Crystal Nickel‐Base Superalloy CMSX‐4®

“…These Y and La-rich phases were mostly observed in the interdendritic regions, adjacent to the coarse cellular ' areas formed during the terminal stages of the directional solidification casting process [7]. These Y and La-rich phases are expected to be combinations of oxides, sulphides and/or oxysulphides of Y and La; in addition, in the materials with high Y+La contents, Ni-Y and Ni-La eutectics are also expected to be present [2,4,5,6,8,9]. Examination of the Ni-Y and Ni-La phase diagrams indicates that Y and La have no major solubility in Ni, and in addition most of the Ni-Y and Ni-La eutectics have relatively low melting points [2].…”

Effect of directional solidification on the structure and properties of Ni3Al-based alloy single crystals alloyed with Cr, Mo, W, Ti, Co, Re, and REM

“…The contents of these metals are limited by the alloying induced increase in the density, their solubil ity in the γ' and γ solid solutions, and the danger of for mation of coarse topologically close packed (TCP) phase precipitates [4]. Interest in studying the effect of alloying with reaction and surface active rare earth metals (REMs), especially lanthanides, on the struc ture and properties of heterophase γ' + γ alloys based on the γ'(Ni 3 Al) phase has recently been quickened [5][6][7][8][9]. Since the atomic radii of REMs are signifi cantly larger than those of aluminum and, of course, nickel, REMs do not dissolve in the solid solutions based on nickel aluminides γ'(Ni 3 Al), NiAl, and γ Ni.…”