Question 2 (25 marks) Larson-Miller parameter is a common means used to estimate the lifetime of a material a that depends on temperature and stress level. Figure 1 shows the creep rupture behaviour of five different materials: Cr-Mo steels, austenitic steels, cast iron, Ti-679 and Ti-6A1-4V, making use of the Larson-Miller model. 1000 800 800 100 Cr-Mo steels 400 Austenitic strels T: 679 50 Cast iron 200 ksi Stress, MPa Ti 6 AI-4V 10 60 40 30 20 10 10 15 20 25 30 T(20 + log 109, Klog (hours) Fig. 1: Creep rupture behaviour using Larson-Miller model. ng Jus ASW de. (d) Suggest another more creep resistant material than Cr-Mo steels, austenitic steels, cast iron, Ti-679 and Ti-6AI-4V. List the chemical compositions for the material that you suggest. Justify your answer with the reasons behind your selection, supported by peer-reviewed journal articles/sources or books. (10 marks)