Alloying Behavior of Ni₃Nb, Ni₃V and Ni₃Ti Compounds

Abstract

The site preference of ternary additions in Ni3X-type GCP compounds was determined from the direction of solubility lobe of the GCP phase on the experimentally reported ternary phase diagrams. In Ni3Nb (D0a), Co and Cu preferred the substitution for Ni-site, Ti, V and W the substitution for Nb-site, and Fe the substitution for both sites. In Ni3V (D022), Co preferred the substitution for Ni-site, Cr the substitution for both sites, and Ti the substitution for V-site. In Ni3Ti (D024), Fe, Co, Cu, and Si preferred the substitution for Ni-site, Nb, Mo and V the substitution for Ti-site. The thermodynamic model, which was based on the change in total bonding energy of the host compound by a small addition of ternary solute, was applied to predict the site preference of ternary additions. The bond energy of each nearest neighbor pair used in the thermodynamic calculation was derived from the heat of compound formation by Miedema’s formula. The agreement between the thermodynamic model and the result of the literature search was excellent. Both transition and B-subgroup elements have two possibilities, i.e., the case of substitution for Ni-site or the case for X-site, depending on the relative value of two interaction energies.

Phase Stability, Elastic and Electronic Properties of Ni3Ti Intermetallic Doped with Mn and Fe: First‐Principles Calculations

“…This means that the doped Mn and Fe atoms all prefer to occupy the Ni sublattice in the Ni 3 Ti phase. This result is consistent with the study by Sugimura et al [42] and the EDS result in our experiment. Two distribution modes of the doped Mn and Fe atoms are considered: aggregated or dispersive distribution.…”

Substitution Behavior of Ni3X-type Compounds with D0a Structure

“…Fe [25] substitutes for both sites, Co [15][16][17]19,20] and Cu [24] mostly for the Ni-site, and Hf [15][16][17], Ta [15][16][17], Ti [15][16][17]26,27], V [28], and W [29,30] mostly for the Nb-site. The ternary systems with Al [15][16][17], with Cr [21][22][23], and with Si [15][16][17] did not provide clear indications of the substitution behavior in Ni 3 Nb because of very small solid solubilities.…”

“…Therefore, the same thermodynamic treatment as that conducted for the L1 2 -type Ni 3 X compounds may be applicable to other Ni 3 X-type compounds. Actually, the alloying behavior of D0a-type Ni 3 Nb [15][16][17], D0 22 -type Ni 3 V [16,17] and D0 24 -type Ni 3 Ti [16,17] compounds has been investigated. Consequently, the agreement for preferable site occupation of the addition between the thermodynamic prediction and the experimental result was found to be excellent.…”

Alloying Behavior of Quaternary Elements in Ni<SUB>3</SUB>(Si,Ti)

“…2,3) The agreement for the substitution behavior of ternary elements between the prediction and the experimental results was found to be excellent. Later, the same treatment has been conducted on other GCP structures, that is, on Co 3 Ti with L1 2 structure, 4) Ni 3 Nb, Ni 3 Ta, and Ni 3 Mo with D0 a structure, Ni 3 V with D0 22 structure, and Ni 3 Ti with D0 24 structure by the present author's group [4][5][6][7][8] and was shown to be successful in predicting the substitution behavior of ternary elements. Regarding the solubility limits of ternary elements X in Ni 3 Al and Ni 3 Ga with L1 2 structure, a successful prediction was found by Ochiai et al, 1) based on the two-dimensional map, in which the difference in heats of formation between Ni 3 Al (or Ni 3 Ga) and Ni 3 X, and the changing rate of lattice parameter by alloying of Ni 3 Al (or Ni 3 Ga) were taken into calculation as two parameters.…”