The viscosities of molten Fe-B alloys (Fe-12.5, 25, 37.5 mol% B alloy) were measured by using an oscillating viscometer. The viscosity measurements were carried out using 99.5% alumina crucible up to about 1 873 K from the liquids temperatures. The viscosities of all alloys were higher than that of pure iron, and the obtained results showed very good Arrhenius type linearity, which indicates that no considerable change of liquid structure exists in each system at the temperatures studied. The viscosity and the activation energy for viscous flow of Fe-B alloy increased monotonously with increasing boron content, which also showed that there is no considerable change in the liquid structure and the mechanism of viscous flow. The viscosity of molten Fe-C alloy previously measured by the authors slightly decreased with increasing carbon content, which was totally different with the behavior of viscosity of Fe-B alloy. It was expected that the interatomic attracting force between the iron and boron was larger than that of iron and carbon because the free energies of formation of Fe2B and FeB in Fe-B system are larger than that of Fe3C in Fe-C system.
- Fe-B alloy