TY - JOUR

T1 - Precipitation and growth behavior of β0 phase in the α2/γ lamellar colonies of an intermetallic Ti-43.5Al-4Nb-1Mo-0.1B alloy

AU - Zhang, Wenjing

AU - Li, Haozhe

AU - Hu, Zhuangzhung

AU - Liang, Yongfeng

AU - Yang, Jihui

AU - Si, Zhixiang

AU - Clemens, Helmut

AU - Scheu, Christina

AU - Dehm, Gerhard

AU - Cha, Limei

N1 - Publisher Copyright: © 2025 Elsevier B.V.

PY - 2025/3/1

Y1 - 2025/3/1

N2 - The precipitation and growth behavior of β(β 0) phases in an intermetallic Ti-43.5Al-4Nb-1Mo-0.1B (at%) alloy were investigated by using X-ray diffraction (XRD), focused ion beam-scanning electron microscopy (FIB-SEM), transmission electron microscopy (TEM) and simulation. The results show that the applied heat treatment changes the volume fraction of the constituting phases and thus the feature of the lamellar microstructure in the alloy. Furthermore, a three-dimensional (3D) reconstruction reveals that β 0 precipitates mainly form small rods within the α 2 lamellae. There, the rod-shaped β 0 precipitates grow in different well-defined directions, and some precipitates are interconnected along their growth paths. TEM investigations indicate that beside the Blackburn orientation relationship (OR): (0001) α 2 //{111} γ, <112̅0> α 2 //<11̅0] γ, the β 0 precipitates which emerge from the α 2 lamellae obey the following OR: (0001) α 2 //{110} β 0 , <112̅0> α 2 //<111> β 0 . In addition, the {110} planes of β 0 have multiple variants. As a consequence, they can grow in different <111> directions in the α 2 lamellae. The low interface energy between β 0 precipitates and α 2 lamellar matrix indicates the precipitates are stable.

AB - The precipitation and growth behavior of β(β 0) phases in an intermetallic Ti-43.5Al-4Nb-1Mo-0.1B (at%) alloy were investigated by using X-ray diffraction (XRD), focused ion beam-scanning electron microscopy (FIB-SEM), transmission electron microscopy (TEM) and simulation. The results show that the applied heat treatment changes the volume fraction of the constituting phases and thus the feature of the lamellar microstructure in the alloy. Furthermore, a three-dimensional (3D) reconstruction reveals that β 0 precipitates mainly form small rods within the α 2 lamellae. There, the rod-shaped β 0 precipitates grow in different well-defined directions, and some precipitates are interconnected along their growth paths. TEM investigations indicate that beside the Blackburn orientation relationship (OR): (0001) α 2 //{111} γ, <112̅0> α 2 //<11̅0] γ, the β 0 precipitates which emerge from the α 2 lamellae obey the following OR: (0001) α 2 //{110} β 0 , <112̅0> α 2 //<111> β 0 . In addition, the {110} planes of β 0 have multiple variants. As a consequence, they can grow in different <111> directions in the α 2 lamellae. The low interface energy between β 0 precipitates and α 2 lamellar matrix indicates the precipitates are stable.

KW - 3D reconstruction

KW - Heat treatment

KW - Interface energy

KW - Intermetallics

KW - Precipitation

KW - TiAl alloy

KW - Transmission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=85219494341&partnerID=8YFLogxK

U2 - 10.1016/j.jallcom.2025.179381

DO - 10.1016/j.jallcom.2025.179381

M3 - Article

VL - 1020.2025

JO - Journal of alloys and compounds

JF - Journal of alloys and compounds

SN - 0925-8388

IS - 15 March

M1 - 179381

ER -