Materials for Energy Systems

(Dr. rer. nat. Christoph Somsen, Prof. Dr.-Ing. Gunther Eggeler)

A secure supply of electrical power is one of the basic requirements for our future. With this in mind, the series of lectures considers engineering materials for power plants, where thermal energy is first transformed into mechanical energy and then into electrical energy. These materials are used for critical components in gas and steam turbines where fossil fuel (gas, oil and coal) is fired. These materials must withstand mechanical loads at high temperatures. High temperature strength not only plays a central role for power plants. It is also a key property for gas turbines for aero engines and in a number of other engineering applications like systems for waste combustion, motor production, industrial furnaces and others. The series of lectures introduces the specific aspects of high temperature deformation (creep and high temperature fatigue). It also considers high temperature corrosion. Two prominent high temperature material systems are treated, tempered martensite ferritic steels (high temperature materials which operate in the 600°C range) and single crystal Ni-base super alloys (high temperature materials which operate in the 1000°C range). For both material classes, the important role of microstructure in high temperature strength will be highlighted.

It will be shown that microstructures are not stable during high temperature service, where they attempt to establish a thermodynamic equilibrium which is often difficult to predict for complex high temperature materials. Moreover microstructural parameters evolve during high temperature service. Thus the volume fractions of phases can change, particles can coarsen, dislocation substructures may alter and cavities can form.

The series of lectures provides practical skills (useful in high temperature design and life time assessments of critical components). It moreover provides a microstructural understanding of elementary processes which affect high temperature materials. As a part of the lecture series students have the possibility to visit power plants, engine manufacturers and producers of high temperature materials.

The class takes place in the winter semester on Thursdays from 1.00 pm to 4.00 pm.

Vorlesungsankündigung WS19_20