Fabricating TiAl alloys with various compositions by twin-wire arc AM

ABSTRACT

TiAl alloys with different Al atomic compositions, i.e. Ti45Al, Ti48Al, and Ti51Al, were produced via double-wire arc-based additive manufacturing by altering the aluminum wire feed rate. The microstructure and mechanical performance of deposited parts were researched. By changing the aluminum composition from 45 at% to 51 at%, the microstructure in the uniform area transforms from equiaxed α₂/γ lamellar and near-lamellar colonies to dual-phase structures and near-lamellar colonies, the volume fraction of α₂ phase decreases from 46.5% to 12.4%, and the total microhardness decreases from 411 to 356 HV. As the aluminum composition increases, the compressive strength presents an increasing trend first and then a decreasing trend, and the compressive ratio presents an increasing trend. The maximum compressive strength and compressive ratio in the vertical and horizontal orientations are 1822.5 MPa, 1732.5 MPa, 19.9%, and 20.2%, respectively.

KEYWORDS:

• Additive
• manufacturing
• GMA
• TiAl
• alloy
• composition
• microstructure
• microhardness
• mechanical
• properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

 This work was funded by National Natural Science Foundation of China, no. 62173280 and no. 51975491, and Sichuan Science and Technology Program, no. 2023NSFSC1956.