Viscosity of liquid amorphizing alloys of iron with boron and silicon

•The kinematic viscosity of the FeSi and the FeSiB melts has been studied.•A nonmonotonic concentration dependence of FeSi melts viscosity has been revealed.•In the range from 20 to 30 at.% Si viscosity of the melts is maximal.•In the FeSiB melts isotherms the viscosity values increase almost monotonically.

The temperature and concentration dependences of the kinematic viscosity of melts of the binary FeSi system with a silicon content from 3 to 45 at.% and melts FeXBYSi(100 − X − Y) (x = 70 and 80 at.%; y = 0 − (100 − x)) have been investigated in the paper. Nonmonotonic concentration dependence of the viscosity and the activation energy of viscous flow of FeSi melts have been obtained. Almost monotonic increase in the viscosity values is observed in concentration dependences of quasi-binary systems of Fe70B30Fe70Si30 and Fe80B20Fe80Si20 when replacing silicon atoms by boron atoms.