Syllabus

Module-1
Introduction - High-temperature materials used at operating temperatures greater than half the melting temperature and their applications. Homologous temperature. Problems associated with high-temperature materials. The usefulness of high-temperature tensile test and its limitations for characterizing high-temperature mechanical behavior. Time-dependent deformation. Difference between ambient and elevated temperature plastic deformation. 06 Hrs
Module-2
Theories and definition of creep. Different methods of creep testing: creep and stress rupture tests. Creep and stress-rupture plots. Stages of creep and associated constitutive equations. Effect of stress and temperature on creep curves. 06 hrs
Module-3
Mechanism of creep deformation. Dislocation glide, dislocation creep, Diffusion creep, and Grain boundary sliding creep. Deformation mechanism map. Determination of stress exponent of the general creep equations. Estimation of activation energy for steady-state creep. Creep fracture micro-mechanisms. Theory of superplasticity. Metallurgical structure change during high-temperature applications. 08 Hrs
Module-4
Module 4) Presentation of engineering creep data, Monkman-Grant relationship. Prediction of the long-term creep data by performing a short-term creep test. Concept of Serby-Dorn and Larson-Miller Parameters. 06 Hrs
Module-5


Time-dependent elastic deformation and its practical applications. Relaxation limit design, relaxation tests, and their applications. Basis for development of creep-resistant materials. Nickel-based superalloys: an important high-temperature alloy, its applications, role of alloying elements, and phase constituents of nickel-based superalloys. Role of intermetallics. Strengthening mechanisms at high temperature. 08 Hrs
Module-6
Single crystal and directionally solidified nickel-based superalloys for aircraft turbine rotors, their manufacturing techniques, and strengthening mechanisms. Other commercially available high-temperature materials, their special characteristics (particularly oxidation resistance), and their applications. 06 Hrs

To familiarize students with the high-temperature materials used at operating temperatures greater than half the melting temperature (in K).

To apprise the students of the creep phenomenon and associated mechanisms that primarily decide the thermal capability of the high-temperature materials.

To equip students with advanced knowledge regarding the presentation methods of creep data and ways of predicting long-time creep properties by performing short-time tests.

To acquaint students with commercially available high-temperature materials, their characteristics, and applications.

The course outcomes (COs) of MM5532 are as follows:

CO1: Students will gain an understanding of high-temperature materials generally used at operating temperatures greater than half of the melting temperature and their applications. Homologous temperature. Problems associated with high-temperature materials. The usefulness of high-temperature tensile test and its limitations for characterizing high-temperature materials.

CO2: Students will get an idea about creep and stress rupture tests, stages of creep curves, and associated constitutive equations.

CO3: Students will be acquainted with the mechanisms of creep, deformation mechanism maps, and metallurgical structure change during high-temperature applications.

CO4: Students will get knowledge about how to predict the creep without performing a long creep test, and the concept of Serby-Dorn and Larson-Miller Parameters. Students will know about theory of superplasticity.

CO5: Time-dependent elastic deformation and its practical applications, relaxation limit design, and relaxation tests and their applications, Nickel-based superalloys: an important high-temperature alloy, its applications, role of alloying elements, phase constituents of nickel-based superalloys.

CO6: Single crystal and directionally solidified nickel-based superalloys for aircraft turbine rotors, their manufacturing techniques, and strengthening mechanisms. Students will be familiar with the other commercially available high-temperature materials, their special characteristics (particularly oxidation resistance), and their applications.

G. E. Dieter, Mechanical Metallurgy, McGraw-Hill , Third Edition, 1988

R. W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials, John Wiley , Fifth Edition, 1989

Michael E. Kassner, Fundamentals of Creep in Metals and Alloys,, Butterworth-Heinemann , 3rd Edition, 2015

Jean-Paul Poirier, Creep of Crystals-High-Temperature Deformation Processes in Metals, Ceramics and Minerals, Cambridge University Press , 1985