TY - JOUR
T1 - Microstructure of a modulated Ti-6Al-4V – Cu alloy fabricated via in situ alloying in laser powder bed fusion
AU - Goettgens, Valerie Sue
AU - Kaserer, Lukas
AU - Braun, Jakob
AU - Letofsky-Papst, Ilse
AU - Mitsche, Stefan
AU - Leichtfried, Gerhard
N1 - Publisher Copyright:
© 2023
PY - 2023/5
Y1 - 2023/5
N2 - In this work, Ti-6Al-4V was in situ alloyed with 15 wt% Cu using laser powder bed fusion (LPBF) to investigate the influence of the eutectoid alloying element Cu on microstructural features. The chemical inhomogeneities owing to in situ alloying are used to allow simultaneous solidification of differently composed material. After LPBF, the matrix material consists of metastable, equiaxed β-Ti and Ti2Cu precipitates. Cu stabilizes β-Ti, and the unique solidification conditions with high thermal supercooling cause the equiaxed grain morphology and the formation of Ti2Cu precipitates. Inclusions, assigned incompletely melted Ti-6Al-4V powder particles, consist of α’/α-Ti. In the transition zone between β-Ti and α’/α-Ti, orthorhombic α’’ is found as nano-sized crystals. For the first time, β-stabilization across a wide area through Cu with a composition of Ti76.2Al5.7V3.2Cu14.9 and the formation of α’’ with the composition of Ti80.2Al5.4V3.3Cu11.1 is shown. It is demonstrated that Cu is a very versatile alloying element in Ti-6Al-4V, significantly impacting microstructural development. Hence LPBF in situ alloying allows more than one alloy composition to be investigated for microstructural features in a single experiment, which could be an interesting approach to alloy development.
AB - In this work, Ti-6Al-4V was in situ alloyed with 15 wt% Cu using laser powder bed fusion (LPBF) to investigate the influence of the eutectoid alloying element Cu on microstructural features. The chemical inhomogeneities owing to in situ alloying are used to allow simultaneous solidification of differently composed material. After LPBF, the matrix material consists of metastable, equiaxed β-Ti and Ti2Cu precipitates. Cu stabilizes β-Ti, and the unique solidification conditions with high thermal supercooling cause the equiaxed grain morphology and the formation of Ti2Cu precipitates. Inclusions, assigned incompletely melted Ti-6Al-4V powder particles, consist of α’/α-Ti. In the transition zone between β-Ti and α’/α-Ti, orthorhombic α’’ is found as nano-sized crystals. For the first time, β-stabilization across a wide area through Cu with a composition of Ti76.2Al5.7V3.2Cu14.9 and the formation of α’’ with the composition of Ti80.2Al5.4V3.3Cu11.1 is shown. It is demonstrated that Cu is a very versatile alloying element in Ti-6Al-4V, significantly impacting microstructural development. Hence LPBF in situ alloying allows more than one alloy composition to be investigated for microstructural features in a single experiment, which could be an interesting approach to alloy development.
KW - Additive manufacturing
KW - Alloy development
KW - Martensitic transformation, Laser powder bed fusion
KW - Titanium alloys
UR - http://www.scopus.com/inward/record.url?scp=85149884577&partnerID=8YFLogxK
U2 - 10.1016/j.mtla.2023.101731
DO - 10.1016/j.mtla.2023.101731
M3 - Article
AN - SCOPUS:85149884577
SN - 2589-1529
VL - 28
JO - Materialia
JF - Materialia
M1 - 101731
ER -