TY - JOUR
T1 - In-situ neutron diffraction characterization on the phase evolution of γ-TiAl alloy during the wire-arc additive manufacturing process
AU - Shen, Chen
AU - Liss, Klaus Dieter
AU - Reid, Mark
AU - Pan, Zengxi
AU - Ma, Yan
AU - Li, Xi
AU - Li, Huijun
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/3/25
Y1 - 2019/3/25
N2 - 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.
AB - 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.
KW - Additive manufacturing
KW - In-situ
KW - Neutron diffraction
KW - Phase characterization
KW - Titanium aluminide
KW - Welding
UR - http://www.scopus.com/inward/record.url?scp=85056712455&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2018.11.150
DO - 10.1016/j.jallcom.2018.11.150
M3 - 文章
AN - SCOPUS:85056712455
VL - 778
SP - 280
EP - 287
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -