Kinetics of grain growth in 0·1 at.-%B doped nickel aluminide containing 23·2 at.-%Al

Nickel aluminide containing 23·2 at.-%Al and 0·1 at.-%B was cold rolled and fully recrystallised at 825, 850, 875, 900, 925, 975, and 1000°C. Increase in grain size as a function of isothermal annealing time at these temperatures was measured. All the data showed excellent fit with the developed equations. The value of m, the exponent of the grain growth equation (Dm- Dm0= Kt), was 2·5. The activation energy for grain growth was 263 kJ g-atom-1. Small changes in the boron content had an appreciable effect on the kinetic parameters. This was attributed to the solute drag effect of boron.