This book presents the results of the Priority Programme "Microstructure and Mechanical Properties of Metallic High-Temperature Materials". The programme has been supported by the Deutsche Forschungsgemeinschaft (DFG) over a period of 6 years from 1991 till 1997. During this time, 45 projects in laboratories in universities and other research institutions were sponsored. The investigations were focused on a limited number of specific groups of materials in order to ensure sufficient overlap between research projects of different researchers on one and the same material. The materials selected were: - light metal PM-aluminium and titanium alloys - ferritic chromium and austenitic alloy 800 steels - nickel-base superalloys with emphasis on monocrystalline materials - nickel- and iron-base oxide dispersion-strengthened (ODS)superalloys.