Grain growth and twin formation in boron-doped nickel polycrystals

Formation of annealing twins and its relation to grain growth is investigated. Our previous studies have established a relation between twin density, grain size, and temperature. A model of the mechanism of their formation based on the emergence of Shockley partial loops on consecutive {1 1 1} planes during grain migration has also been developed previously. This model can satisfactorily explain some experimental and theoretical results found over the years. In this paper we provide additional experimental evidence in support of our model by investigating twin formation in boron-doped nickel. We find that boron addition slows down grain growth, though the kinetics of grain growth remains parabolic. There is a drastic reduction in twin density due to boron addition especially around a boron content of ∼200 ppm.