TY - JOUR

T1 - Alloying elements in intermetallic γ-TiAl based alloys – A review on their influence on phase equilibria and phase transformations

AU - Musi, Michael

AU - Graf, Gloria

AU - Clemens, Helmut

AU - Spörk-Erdely, Petra

N1 - Publisher Copyright: © 2023 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH.

PY - 2023/7/9

Y1 - 2023/7/9

N2 - Intermetallic γ-TiAl based alloys are innovative structural materials dedicated to applications in the automotive and aeronautic industries. Especially their low density, high specific yield strength, and excellent resistance against creep and oxidation make them a suitable choice for structural high-temperature components in combustion engines. However, further improvement of their properties and processability is required to conquer new application areas and facilitate cost-effective production. While the incorporation of additional alloying elements is a promising possibility, their effects on the phase transformations and phase equilibria need to be considered rigorously. In this context, this review provides a detailed survey of the research work on the influence of technically important alloying elements on the Ti–Al phase diagram. First, an introduction to the fundamentals of the phase transformations in γ-TiAl based alloys and the consequences of changed cooling conditions, relevant for example to the latest developments within the field of processing, is given. Afterward, the alloying elements, categorized with respect to their stabilization effect, are discussed and their particularities are highlighted. Topics covered include established ternary phase diagrams and isoplethal sections, the stabilization of additional phases as well as the influence of alloying elements on the microstructure of modern engineering intermetallic γ-TiAl based alloys.

AB - Intermetallic γ-TiAl based alloys are innovative structural materials dedicated to applications in the automotive and aeronautic industries. Especially their low density, high specific yield strength, and excellent resistance against creep and oxidation make them a suitable choice for structural high-temperature components in combustion engines. However, further improvement of their properties and processability is required to conquer new application areas and facilitate cost-effective production. While the incorporation of additional alloying elements is a promising possibility, their effects on the phase transformations and phase equilibria need to be considered rigorously. In this context, this review provides a detailed survey of the research work on the influence of technically important alloying elements on the Ti–Al phase diagram. First, an introduction to the fundamentals of the phase transformations in γ-TiAl based alloys and the consequences of changed cooling conditions, relevant for example to the latest developments within the field of processing, is given. Afterward, the alloying elements, categorized with respect to their stabilization effect, are discussed and their particularities are highlighted. Topics covered include established ternary phase diagrams and isoplethal sections, the stabilization of additional phases as well as the influence of alloying elements on the microstructure of modern engineering intermetallic γ-TiAl based alloys.

KW - alloying elements

KW - microstructure

KW - phase diagrams

KW - phase transformations

KW - titanium aluminides

UR - http://www.scopus.com/inward/record.url?scp=85173398082&partnerID=8YFLogxK

U2 - 10.1002/adem.202300610

DO - 10.1002/adem.202300610

M3 - Review article

VL - 26.2024

JO - Advanced engineering materials

JF - Advanced engineering materials

SN - 1527-2648

IS - 4

M1 - 2300610

ER -