Structure of amorphous iron-based coatings processed by HVOF and APS thermally spraying

High-velocity oxy-fuel (HVOF) and air-plasma spraying (APS) were used to produce Fe3Si and FeNb alloy coatings. Adjusting the spraying conditions, amorphous coatings were obtained from the FeNb powder. However, for the Fe3Si powder, crystalline deposits were produced in all cases. Boron additives were used to improve the aptitude of the Fe3Si alloy to form an amorphous phase. In this perspective, first-principle calculations were elaborated to investigate the electronic structure of crystalline FeNb and Fe3Si. It was shown that the introduction of boron impurities into the alloy matrix lead to the lowering of the structural stability, and made its electronic density of state more comparable to the corresponding FeNb structure.