# Modeling of [alpha]/[alpha][sub 2] phase equilibrium in the Ti-Al system by the cluster variation method

## Abstract

The cluster variation method was applied to the phase equilibrium calculations for the h.c.p. structure based on the tetrahedron approximation taking into account a c/a ratio. The model was applied to the [alpha]/[alpha][sub 2] equilibrium in the Ti-Al system with Lennard-Jones (L-J) pair potentials for describing the energy term of the system. A good fit for [alpha]/[alpha][sub 2] phase boundaries in the Ti-rich region of the Ti-Al system was obtained with experimental phase diagram by small change of L-J potential parameters which were obtained with experimental phase diagram by small change of L-J potential parameters which were roughly determined from the experimental data suggesting a possibility of a satisfactory treatment of [alpha]/[alpha][sub 2] equilibrium in the Ti-Al system. The CVM approximation with tetrahedron and triangle clusters resulted in the same configuration entropy for the h.c.p. and f.c.c. structures when a c/a ration of the h.c.p. structure had the ideal value of (8/3)[sup 1/2].

- Authors:

- (National Research Inst. for Metals, Tokyo (Japan) Materials Design Div.)

- Publication Date:

- OSTI Identifier:
- 5188302

- Resource Type:
- Journal Article

- Journal Name:
- Acta Metallurgica et Materialia; (United States)

- Additional Journal Information:
- Journal Volume: 42:3; Journal ID: ISSN 0956-7151

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; MICROSTRUCTURE; TITANIUM BASE ALLOYS; BINARY ALLOY SYSTEMS; MATHEMATICAL MODELS; PHASE STUDIES; ALLOY SYSTEMS; ALLOYS; TITANIUM ALLOYS; 360102* - Metals & Alloys- Structure & Phase Studies

### Citation Formats

```
Onodera, H., Abe, T., and Yokokawa, T.
```*Modeling of [alpha]/[alpha][sub 2] phase equilibrium in the Ti-Al system by the cluster variation method*. United States: N. p., 1994.
Web. doi:10.1016/0956-7151(94)90284-4.

```
Onodera, H., Abe, T., & Yokokawa, T.
```*Modeling of [alpha]/[alpha][sub 2] phase equilibrium in the Ti-Al system by the cluster variation method*. United States. doi:10.1016/0956-7151(94)90284-4.

```
Onodera, H., Abe, T., and Yokokawa, T. Tue .
"Modeling of [alpha]/[alpha][sub 2] phase equilibrium in the Ti-Al system by the cluster variation method". United States. doi:10.1016/0956-7151(94)90284-4.
```

```
@article{osti_5188302,
```

title = {Modeling of [alpha]/[alpha][sub 2] phase equilibrium in the Ti-Al system by the cluster variation method},

author = {Onodera, H. and Abe, T. and Yokokawa, T.},

abstractNote = {The cluster variation method was applied to the phase equilibrium calculations for the h.c.p. structure based on the tetrahedron approximation taking into account a c/a ratio. The model was applied to the [alpha]/[alpha][sub 2] equilibrium in the Ti-Al system with Lennard-Jones (L-J) pair potentials for describing the energy term of the system. A good fit for [alpha]/[alpha][sub 2] phase boundaries in the Ti-rich region of the Ti-Al system was obtained with experimental phase diagram by small change of L-J potential parameters which were obtained with experimental phase diagram by small change of L-J potential parameters which were roughly determined from the experimental data suggesting a possibility of a satisfactory treatment of [alpha]/[alpha][sub 2] equilibrium in the Ti-Al system. The CVM approximation with tetrahedron and triangle clusters resulted in the same configuration entropy for the h.c.p. and f.c.c. structures when a c/a ration of the h.c.p. structure had the ideal value of (8/3)[sup 1/2].},

doi = {10.1016/0956-7151(94)90284-4},

journal = {Acta Metallurgica et Materialia; (United States)},

issn = {0956-7151},

number = ,

volume = 42:3,

place = {United States},

year = {1994},

month = {3}

}