The Stability of γ ’-Co3(Al,W) Phase in Co-Al-W Ternary System

Yuki Tsukamoto; Satoru Kobayashi; Takayuki Takasugi

doi:10.4028/www.scientific.net/MSF.654-656.448

Paper Titles

The Effect of Ti Addition on Phase Equilibria among Ni (A1), Ni₃Al (L1₂) and Ni₃V (D0₂₂) Phases
p.432

Microstructural Characterization of Nb-Al Base ODS Alloys
p.436

Alloying Behavior of Ni₃Nb, Ni₃V and Ni₃Ti Compounds
p.440

Alloy Design of Nb-Si Based High Temperature Alloys by Phase Stability Control
p.444

The Stability of γ ’-Co₃(Al,W) Phase in Co-Al-W Ternary System
p.448

The Effect of Alloying Elements on Microstructure and Strength Property of Dual Two-Phase Intermetallic Alloys Based on Ni₃Al-Ni₃V Pseudo-Binary Alloy System
p.452

Phase Transition and Ordering Temperatures of TiAl-Mo Alloys Investigated by In Situ Diffraction Experiments
p.456

Effect of Y on Microstructure and Mechanical Properties of a Ti Alloy
p.460

Effects of Electropulsing Treatment on the Precipitation Behaviour of Grain Boundary Carbides in GH3044 Alloy
p.464

HomeMaterials Science ForumMaterials Science Forum Vols. 654-656The Stability of γ ’-Co3(Al,W) Phase in Co-Al-W...

The Stability of γ ’-Co₃(Al,W) Phase in Co-Al-W Ternary System

Abstract:

The thermodynamic stability ’- Co3(Al,W) phase (L12) in the Co-Al-W ternary system at 900 °C was investigated through microstructure and EPMA analysis on a heat-treated bulk alloy. To promote microstructural evolution, the bulk alloy was cold rolled before heat treatment. By heating at 900 °C, the ’ phase was formed discontinuously in contact with the -Co (A1) phase. With increasing heat treatment time, however, the fraction of ’ phase decreased while that of , CoAl (B2) and Co3W (D019) phases increased. These results are consistent with our previous work with a diffusion-couple method, indicating that the ’ phase is metastable, and the three phases of, CoAl and Co3W are thermodynamically stable at 900 °C.