Experimental Research and Phase-field Simulation of Coarsening Kinetics of γ Precipitates in Co-Ti Alloys

Abstract:

The microstructure evolution and coarsening behaviors of disordered γ phase in the inverse Co-19.7Ti alloy have been investigated by experiment and phase-field method. Both the experimental and simulated results show that the morphologies of γ particles evolved from near-circular shape to plate-like shape as the aging time increases. The coarsening kinetics for the mean particle size obeys the cube law r₃ = kt, and it can be obtained as: . There exist two distinct stages of the mean particle sizes increase versus aging time, the growth rate is dramatically larger in stage I and has a relatively slower increase in stage II. The summit value of precipitate size distributions become larger and the breadth of the distributions decrease from 700_oC to 750_oC, the simulated results reproduce well the experimental results.