High-Temperature Materials

Faculty of Engineering and Computer Science

Version 7.0 of 06/17/2020

11M0651

High-Temperature Materials

Angewandte Werkstoffwissenschaften (M.Sc.)

3

Materials that are used at temperatures ranging from 500°C up to 1500°C are subject of the lecture. Such materials have to withstand extreme loading conditions, e.g., in aeroengines, gas and steam tubines or in petrochemical industry. Service live is determined by time-dependent damage mechanisms, such as power-law creep and high temperature corrosion. These mechanisms are explained in detail and discussed in terms of concepts to increase the materials corrosion resistance and high temperatur strength. The second part of the lecture is focussed on particular materials that are commonly used for high temperature applications: heat resistand steels, poly- and single-crystalline nickel-base superalloys, cobalt alloys, intermetallics and ceramics.

Lecture:• Technical rquirements for materials used at elevated temperatures, driving force: energy technologies (gas and steam turbines, fuel cells), aerospace industries, petrochemical industries.• Introductions in high-temperature oxidation and corrosion: mechanisms and protection.• Mechanical damage at high temperatures: creep and thermomechanical fratigue.• Precipitation and solid-solution strengthening.• Metallic high-temperature alloys: heat-resistant steels, nickel- and cobalt-base alloys.• directional and single-crystalline solidification, ODS superalloys.• Metallurgical alloying concepts - computer-based calculation of phase diagrams (CALPHAD).• Intermetallics and Ceramics.

Laboratory Exercises:Metallographic analysis of an unknowen high-temperature material and quantitative assessment of its high-temperature corrosion behaviour - presentation in English language.

Knowledge Broadening
The students know about the behaviour of various metallic and ceramic materials at high temperatures as a consequence of the damage mechanisms high-temperature oxidation and corrosion, creep, and thermomechanical fatigue.
Knowledge Deepening
With a focus on heat-resitant steels, nickel-base superalloys, engineering cermaics and interentallics, the students get a deeper understanding of the metal casting, forming and strengthening technologies. They have a broad knowledge about the effetcs and mutual interaction of the various alloying elements and the application of computatiponal thermodynamics in today's alloys design.
Instrumental Skills and Competences
By experimental laboratory work in small teams the students are anabled to apply (i) thermogravimetric analysis to quantify oxidation kinetics and (ii) precipitation strengthening of nickel-base superalloys. They know how to use analytical scanning electron microscopy to evaluate the above-mentioned processes.
Communicative Skills and Competences
The students are able to work experimentally and to communicate in small teams. Furthermore they are able to present the results in the context of the knowledge they gained from the lecture and additional literature.
Systemic Skills and Competences
The students should be able to estimate the material behaviour at high temperatures, being determined by the damage mechanisms high-temperature oxidation/corrosion, creep and thermomechanical fatigue. Based on this estimation they should know which materials concept to select and which kind of heat and/or coating concept might be useful. They know quantitatively the relationship between alloy chemical composition and the formation of intended and non-intended phases and surface layers (oxides scales) in such a way that they are able to develop and improve materials for particular high-temperature applications.

lecture / laboratory exercises

Introdution in Materials Science and Engineering, Mechanics - Elastostatics, Mechanics of Materials

Mola, Javad

• Mola, Javad
• Jahns, Katrin

5

1. Bürgel, R., Maier, H.J.; Niendorf, T.: Handbuch Hochtemperaturwerkstofftechnik, Vieweg-Verlag, Wiesbaden 2011.
2. Birks, N.; Meier, G. H.; Pettit, F.S.: Introduction to the High-Temperature Oxidation of Metals, Cambridge University Press, Cambridge 2006.
3. D.J. Young: High Temperature Oxidation and Corrosion of Metals, 2nd. ed. Springer 2016
4. Sims, Stoloff, Hagel: Superallys II, Wiley-Verlag, New York 1987.

Knowledge of the behaviour of metallic and ceramic high-temperature materials under complex mechanical and high-temperature-corrosion loading conditions, systematic materials selection, service-ife prediction, alloying and heat tretament of high temperature materials.

1 Term

Only Winter Term

English