Composition and Microstructure of Engineering Materials

Introduction

Materials serve the production of functioning components. The internal structure of all materials reflects their production and composition and gives information about their ageing during the operation of the manufactured component. The production of a component has a great influence on its reliability. Its assessment requires the understanding of the machinability of the material and the consequences of machining. The geometrical and chemical characterisation of engineering surfaces is also important for the evaluation of a component.

Apart from purely mechanical damage, such as incipient cracks and creep pores, chemical changes due to diffusion from the outside into the structure or reactions with the surrounding medium at the surface can also occur in the material being used. Each change of the material structure and its surface such as ambient temperature, mechanical load and the surrounding medium exert a joint effect on the material and alter its properties, behaviour and service life.

Both quality and change of the material in use are subject to investigation and research using various methods and techniques. Metals and ceramics are used on their own or combined in layer systems, materials groups and composite materials. These material classes are investigated by Division 5.1. Changes in the material take place at all scales, this is why it is necessary to proceed from a macroscopic view with the naked eye, to the optical microscope and the X-ray photography and finally with transmission electron microscope into the nano-world in order to obtain an exact picture of the mechanisms of change in the material and the function of the component. For this purpose scientific work is carried out which provides the capability for development of new methods, expert opinions and industrial co-operation.

Division 5.1 deals with the structure of conventional and new structural metallic and ceramic materials. The methods cover conventional materialography and X-ray photography and highly specialised methods such as transmission electron microscopy and phase analysis by electron diffraction. These and other methods are used in the following fields of competence.

Competences

• Quantitative materialography
• Phase analysis
• Electron microscopy
• Engineering materials
• Constitution and thermodynamics

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