Studies on Titanium Alloys for Aerospace Application

Abstract

Abstract. Since the development of the Ti54M titanium alloy in 2003, its application within the aerospace sector has gradually increased due to the combination of properties such as improved forgeability and machinability, low flow stress at elevated temperatures, and superplastic characteristics. However, for the successful exploitation of Ti54M a comprehensive understanding of its mechanical characteristics, microstructure stability, and superplastic behaviour is required.The superplastic forming of titanium alloys is characterised by high deformation at slow strain rates and high temperatures which influence the material microstructure, and in turn, determine the forming parameters. These mechanisms make the prediction of the material behaviour very challenging, limiting its application within the aerospace industry. Even though Ti54M has been commercially available for over 10 years, further studies of its mechanical and superplastic properties are still required with the aim of assessing its applicability within the aerospace industry as a replacement for other commercial titanium alloys. Therefore, in this work a study of the mechanical and superplastic properties of Ti54M, in comparison with other commercial titanium alloys used in the aerospace industry -i.e. Ti-6AL-4V, and Ti-6-2-4-2 -is presented. The final objective of this study, carried out at the Advanced Forming Research Centre (AFRC, University of Strathclyde, UK), is to obtain material data to calibrate and validate a model capable of estimating the behaviour and grain size evolution of titanium alloys at superplastic conditions.

A Study on Modelling the Superplastic Behaviour of Ti54M Alloy

“…FIG. 1 Grain size evolution of primary α phase over time Secondly, the flow curves reported by Gomez-Gallegos et al [8] were fitted by using the grain size evolution data as an input to the constitutive Eq. 4.…”

“…The present work utilizes a microstructural-based power-law model to predict the superplastic behaviour of Ti54M alloy at 815 °C and compare it to the superplastic behaviour of Ti64 alloy at 925 °C. These temperatures were reported to be optimal for Ti54M and Ti64 alloys based on strain rate sensitivity values and uniform deformation conditions [7,8].…”

“…The parameters of the material model have been calculated based on material experimental data by means of a developed Matlab script for Ti54M and Ti64 alloys. The material experimental data used in this work are reported in the literature [7,8]. Mandal et al [7] studied the grain size evolution of Ti54M and Ti64 alloys under superplastic deformation for various test conditions.…”

“…Mandal et al [7] studied the grain size evolution of Ti54M and Ti64 alloys under superplastic deformation for various test conditions. Gomez-Gallegos et al [8] investigated the mechanical and superplastic properties of Ti54M and Ti64 alloys at various temperatures via high temperature tensile tests.…”

Numerical Modeling of Superplastic Punchless Deep Drawing Process of a Ti-6Al-4V Titanium Alloy

“…The Ti-6Al-4V titanium alloy (UNS R56400 or Grade 5) is a kind of an α/β alloy which is useful in various branches of manufacture, including the aerospace industry, for the production of e.g. fan blades and airframes [1,12]. The main advantages of the Ti-6Al-4V alloy, which determines its wide application in the industry sector, are a high mechanical strength, high working temperatures as well as a good welding performance [9,47,48].…”