Study of nanometer-scaled lamellar microstructure in a Ti-45Al-7.5Nb alloy - Experiments and modeling

TY - JOUR

T1 - Study of nanometer-scaled lamellar microstructure in a Ti-45Al-7.5Nb alloy - Experiments and modeling

AU - Fischer, F. D.

AU - Waitz, T.

AU - Scheu, Ch

AU - Cha, L.

AU - Dehm, G.

AU - Antretter, T.

AU - Clemens, H.

N1 - Funding Information: The authors appreciate the funding by Austrian FWF under the project “Massive Transformation – Experiments and Simulations”, Project number P20709-N20. The HRTEM experiments were performed at the Max-Planck-Institute for Metals Research, Stuttgart, and were supported by the IP3 project ESTEEM of the European Commission (contract number 0260019a). T.W. acknowledges the support by the research project “Bulk Nanostructured Materials” within the research focus “Materials Science” of the University of Vienna.

PY - 2010/4

Y1 - 2010/4

N2 - Quenching of Ti-45 at%Al-7.5 at%Nb from the single α-phase region to room temperature followed by aging below the eutectoid temperature leads to the precipitation of ultra-fine γ-TiAl lamellae. In addition to an extensive experimental program, reported by Cha et al. in Intermetallics 16 (2008) 868-875, in this work a micromechanical and thermodynamical model is presented for the formation of γ-TiAl lamellae within the α2-Ti3Al parent phase. A global transformation condition allows to predict a thickness to length ratio in accordance with experimental observations. Furthermore, a local transformation condition offers the basis for a kinetic law. The modeling concept can be applied to similar problems of combined diffusive and displacive phase transformations.

AB - Quenching of Ti-45 at%Al-7.5 at%Nb from the single α-phase region to room temperature followed by aging below the eutectoid temperature leads to the precipitation of ultra-fine γ-TiAl lamellae. In addition to an extensive experimental program, reported by Cha et al. in Intermetallics 16 (2008) 868-875, in this work a micromechanical and thermodynamical model is presented for the formation of γ-TiAl lamellae within the α2-Ti3Al parent phase. A global transformation condition allows to predict a thickness to length ratio in accordance with experimental observations. Furthermore, a local transformation condition offers the basis for a kinetic law. The modeling concept can be applied to similar problems of combined diffusive and displacive phase transformations.

KW - A. Titanium aluminides

KW - B. Phase transformation

KW - C. Thermal treatment

KW - D. Microstructure

KW - E. Modeling

UR - http://www.scopus.com/inward/record.url?scp=77649186733&partnerID=8YFLogxK

U2 - 10.1016/j.intermet.2009.09.012

DO - 10.1016/j.intermet.2009.09.012

M3 - 文章

AN - SCOPUS:77649186733

SN - 0966-9795

VL - 18

SP - 509

EP - 517

JO - Intermetallics

JF - Intermetallics

IS - 4

ER -