NICKEL-BASE SUPERALLOYS - EVOLUTION, PRESENT STATUS AND POTENTIAL

The nickel base superalloys are developed for critical applications in gas turbines and are presently being used at temperatures up to about 1400 K. This is about 80% of the absolute melting temperature (1726 K ) of nickel. Only marginal increase in their high temperature capabili ty is therefore possible. The alternative groups of materials are stil l in developmental stage. More effective use of the superalloys in ter ms of increased service life can be achieved through a better understa nding of the processes of deformation and damage in these alloys. The characteristics of their deformation behaviour at elevated temperature s and its present understanding are discussed.