Light-optical bright field micrograph of a metallographic section of a Ti6242 alloy
The group “Central Analytical Research and Metallography” is a central facility at the Institute of Materials Research. Characterization of materials with respect to microstructure, chemical and phase composition is carried out as a scientific and technical service. These works deliver an essential contribution to the understanding of the interrelationship between material synthesis and properties. The interpretation of the microstructure and analytic data is carried out in close collaboration with 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. For this purpose, a Zeiss Ultra 55 scanning electron microscope, a FEI Helios 600i Dual Beam / Focused Ion Beam system (FIB) and a Philips Tecnai F30 transmission electron microscope is used as well as a Zeiss LSM 700 laser scanning microscope and various light microscopes. For phase and texture analysis, a Siemens D5000 X-ray diffractometer is available in addition to a Bruker D8 Advance powder diffractometer equipped with heating stages for temperatures up to 1600°C. Texture analysis and spatially resolved X-ray diffraction is performed with a Bruker D8 GADDS system.
Furthermore, X-ray fluorescence analysis is can be provided at the institute.
Effective sample preparation is the basis for further microstructural work. This is the purpose of the well-equipped metallographic laboratory. Samples for 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.
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. Besides 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 (Gatan DuoMill and PIPS, Bal-Tec RES100) and a TEM lamella lift-out system on the FEI Helios 600i FIB.