The interrelated effect of initial melt undercooling, solute trapping and solute drag on the grain growth mechanism of as-solidified Ni-B alloys

The interrelated effects of initial melt undercooling, solute trapping and solute drag on the grain growth mechanism was investigated in as-solidified Ni-B alloys. The supersaturated granular grains were prepared by employing the glass fluxing and subsequent rapid quenching. Subjected anneal to the as-quenched grains, an alternant grain growth manner was detected with increasing initial melt undercooling, i.e. normal grain growth → abnormal grain growth → normal grain growth. In combination of the solute trapping model of undercooled melt and solute drag model of solid-state grain growth, it can be concluded that when P_G ≪ P_D or P_G ≪ P_D, the normal grain growth occurred and when P_G ≈ P_D, the abnormal grain growth occurred.