Creep deformation behaviour in single phase c-TiAl alloy has been an extensively studied topic since the late 1970 s. A lot of literatures have reported creep behaviour of c-TiAl alloys, manufactured using differ- ent processing techniques [1–7] . The present discussion revisits the original work on understanding the tensile creep deformation behaviour of wrought single-phase c-TiAl alloy by Hayes et al. [8]and is aimed to develop an understanding of steady state creep, through strain vs strain rate and strain vs ln(strain rate) plots. Besides, it also attempts to study the variation of stress exponent with temperature between760 and 900 ⁰C and also, to determine activation energies using the two most common approaches, namely: Zener-Hollomon (Z-H) [9]and Sherby-Dorn (S-D, temperature compensated time approach) [10] for stress levels of 69.4 and 103.4 MPa between 760 and 900 ⁰C. /C2112020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientiﬁc committee of the International Confer- ence on Materials, Manufacturing and Mechanical Engineering for Sustainable Developments-2020. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/ 4.0/). 1. Introduction A series of reports on room temperature tensile deformation behaviour of c- TiAl alloys show that the near- c, two phase com- positions having Al contents around 48 at.% possess the highest strengths and ductilities [1–3,11–18] . Extensive creep deformation studies have been carried out on a number of two phase near- c TiAI alloys produced by various processing routes [8,19–29] .I n addition, compression creep studies have been carried out on a number of binary single phase c-TiAl alloys and a number of liter- atures have reported that minimum strain rates during creep test- ing at different regimes of temperature and stress, is hugely dependent on the grain size of materials [1,8,19,30,31] . Minimum strain rate of such intermetallic alloys may be deﬁned in terms of Mukherjee-Bird-Dorn equation [32–34] . From a fundamental point of view, a study of the creep deformation behaviour of single phase TiAl is highly essential to provide useful insight into the deformation behaviour of the two phase TiAl alloys.1.1. Motivation The work of Hayes et al. [8]presents and discusses an analysis of the minimum strain rate deformation as well as an analysis of the tertiary creep behaviour of a wrought single phase c-TiAl alloy within temperature range of 760-1000 ⁰C and stress range of 32– 345 MPa. The analysis by Hayes et al. [8]was carried out through determination of apparent creep activation energies, at different temperature regimes, for various stresses, followed by theoretical calculation of stress exponents at different stress regimes, for dif- ferent temperatures. This was followed by the prediction of the main mechanism for creep rupture at different temperatures, in a given stress range, using Monkmann-Grant (M /C0G) plots [9]and extensive microstructural characterisation using Optical micro- scope and the Transmission Electron Microscope (TEM) [8]. The present discussion revisits the original work by Hayes et al [8]and is aimed to develop an understanding of steady state creep, through strain rate vs strain and ln(strain rate) vs strain plots.Besides, it also attempts to (i) determine variation in stress expo- nent with temperature between 760 and 900 ⁰C and (ii) to deter- mine activation energies through Zener-Hollomon (Z-H) and Sherby-Dorn (S-D, temperature compensated time approach) for stress levels of 69.4 and 103.4 MPa between 760 and 900 ⁰C. Some of the major claims of the work by Hayes et al. [8]are: https://doi.org/10.1016/j.matpr.2020.11.189 2214-7853/ /C2112020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientiﬁc committee of the International Conference on Materials, Manufacturing and Mechan ical Engineering for Sustainable Developments-2020.This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).E-mail address: mainaksaha1995@gmail.comMaterials Today: Proceedings 46 (2021) 3187–3192 Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.else vier.com/locate/matpr /C15Wrought single phase c-TiAl alloy does not exhibit tertiary creep between 760 and 900 ⁰C, at stress levels of 69.4 MPa and 103.4 MPa. /C15There is no steady state creep observed at 832 ⁰C, at stress levels of 69.4 MPa, for both interrupted and uninterrupted tests. /C15c-TiAl alloys do not exhibit dislocation creep at 760 ⁰C, 832 ⁰C and 900 ⁰C between stress level: 32–345 MPa. 2. Discussion Table 1 shows the composition of single phase c-TiAl alloy, forged, heat treated and ﬁnally subjected to tensile creep testing, as discussed in the work of Hayes et al [8]. As discussed earlier, that only constructing strain vs time plot to determine ‘‘min. strainrate” and designating the same to be the ‘‘steady state strain rate”, may be highly misleading for a number of materials, which do not exhibit steady-state creep [18]. Ti-53Nb-1Al, for instance, whether tested to rupture or terminated at mid-strains of 0.18% and 0.5% at 832 ⁰C, exhibited a very less amount of steady-state creep. In the case of creep test till rupture, signiﬁcant primary creep is exhibited whereas, in the case of creep test terminated at 0.18% strain, there is no primary creep regime and for the creep test till 0.5% strain, the primary creep regime is in between the two aforementioned extremes. In all cases, there is a very early onset of tertiary creep, However, the rate of tertiary creep in all the three samples is sig- niﬁcantly different, as indicated by slopes of plots in Fig. 3 (a) and (b). Besides, from Fig. 1 (a) and (b), the strain rate as well as strain for initiation of tertiary creep in three samples, also vary, Table 1 Composition of the alloy (used by Hayes et al. [8]). El. Ti Al Nb Fe H O N C at. % 45.9 52.9 0.91 0.048 0.0219 0.1523 0.0026 0.0555 Fig. 1. (a) Strain rate vs Strain and (b)ln(strain rate) vs strain plots at 832 ⁰C for sample subjected to interrupted tensile creep testing. 2 interruption (terminating) stresses were used by Hayes et al. [8]viz. 0.18% and 0.5% strain to fracture. Fig. 2. ln (strain rate, in h) vs 1/T plot (marked as black) and Sherby -Dorn plot (marked as red) to determine creep activation energies at different temperatu re regimes at (a) 69.4 MPa and (b)103.4 MPa. (For interpretation of the