Light-optical bright field micrograph of a metallographic section of a Ti6242 alloy
Characterization of materials with respect to microstructure, chemical and phase composition is carried out as a scientific and technical service. These studies deliver an essential contribution to the understanding of the interrelationship between the materials synthesis and properties. The interpretation of the microstructure and analytic data is carried out in close collaboration whit the other departments and work groups of our institute.
At the Institute of Materials Research, light microscopy as well as scanning and transmission electron microscopy is used to deal with questions concerning microstructure and analytical issues. Integral phase analysis at room and elevated temperatures as well as texture analysis is carried out by means of three X-ray diffractometers. Additionally, X-ray fluorescence analysis is available at the institute.
Conjunction of the different integral and microscopic methods delivers results exceeding the power of isolated investigations by far. Especially the combination of imaging (LM, SEM, TEM), composition-sensitive imaging (BSE and HAADF imaging), diffraction (XRD, EBSD, SAED/CBED) and spectroscopy (EDX, EELS and EFTEM) is extremely efficient in this context.
Effective sample preparation establishes the basis for further micro structural work. For this purpose, a well-equipped metallographic laboratory is available. Samples for light optical or scanning electron microscopy can be processed further by chemical, plasma or ion beam etching. There is also equipment for coating of insulator samples on-hand.
The sample preparation through a focused ion beam (FIB) enables microsectioning of µm-sized details as well as the three-dimensional volume reconstruction by recursive application of the technique.
Special attention has to be paid to the preparation of samples for transmission electron microscopy. Here, it is necessary to produce samples exhibiting a few dozen of nanometers in thickness at the regions of interest. In addition to the complete metallographic equipment, various methods of mechanic preparation (as sawing, dimpling and ultrasonic disc cutting) are available, as well as different instruments for ion beam etching and the TEM lamella production and lift-out by FIB techniques.