Abstract
From the first forged turbine blades made of iron base alloys to the present nickel base single-grain
turbine blades and vanes manufactured by directional solidification, an enormous amount of research
has been directed to attaining the hottest possible combustion chamber temperatures in jet engines.
Temperature has been increased by about 15 K each year for the last two decades, improving the
thermodynamic efficiency of the engines. The more recent developments concern the manufacturing
of single-grain parts made of nickel base superalloys with large amount of the