Magnetic and mechanical properties of the gradient FeSi alloys fabricated by magnetron sputtering

We have applied double-side physical vapor deposition and subsequent annealing for preparation of gradient FeSi alloys with an average thickness of 0.35 mm. FeSi layer was deposited on Fe-3 wt.% Si sheet substrate, followed by vacuum annealing at temperatures ranging from 1160 to 1240 °C for different time. The Si profiles over the sample thickness are greatly dependent on the annealing, demonstrating a maximal gradient for those annealed at 1180 °C for 30 min. The distribution of the Si gradient leads to a reduction of core losses and an improvement of mechanical properties as well. The elongation increases from 4.8% for the alloy with homogeneous Si distribution to 12.3% for the gradient FeSi alloy, and the tensile strength for the latter is also larger than that of the former.