The kinetics, morphology and composition of the formation of TCP phases in an experimental alloy containing no tungsten is studied. At high temperature P phase forms after 20 h, whereas below 950 deg C the phases mu and R occur. At lower temperatures a polycrystalline form of sigma phase is obaeerved which is meta-stable but acts as a nucleation site for the other phases. The phase occurrence and compositions are compared with a thermodynamic model using a rhenium-containing database, and reasonable agreement is found for the P, R and sigma phases. Hoever the model underestimates thestability of the mu phase.
展开▼
