Title

In-situ neutron diffraction characterization on the phase evolution of y-TiAl alloy during the wire-arc additive manufacturing process

RIS ID

131825

Publication Details

Shen, C., Liss, K., Reid, M., Pan, Z., Ma, Y., Li, X. & Li, H. (2019). In-situ neutron diffraction characterization on the phase evolution of y-TiAl alloy during the wire-arc additive manufacturing process. Journal of Alloys and Compounds, 778 280-287.

Abstract

γ-phase based titanium aluminide has continuously been attractive because of its potential application in modern light-weight, high-temperature turbines, such as aircraft engines. However, it suffers from its poor plasticity and during manufacturing and processing. In recent years, wire-arc additive manufacturing process has been proved feasible of fabricating γ-phase based titanium aluminide structures with full density and relatively lower cost compared to traditional powder metallurgy processing. In the present research, the temperature process of a single-pass deposition process during the additive manufacturing was simulated as a linear heating (up to 1623 K) and cooling process in a vacuumed furnace, and in-situ investigated using neutron diffraction. As a result, compared to the initial as-fabricated state, the volume fraction of α2-phase increased by 2.54% after the heat treatment. Crystallographic aspects, specifically the α/α2 ↔ γ phase transformation and lattice evolutions of γ-phase are discussed in detail. According to the results obtained, the γ → α2 transition temperature in the present binary alloy is 1393 K, which largely deviates from earlier results collected from γ-phase based titanium aluminides with Nb addition. Also, the lattice evolutions of γ-phase in a function of time/temperature are linear fitted and responses of lattice strains (a, c axis and volumetric) to temperature are calculated.

Please refer to publisher version or contact your library.

Share

COinS
 

Link to publisher version (DOI)

http://dx.doi.org/10.1016/j.jallcom.2018.11.150