Abstract
In order to clarify the influence of iron loss and domain structure of TiN-coated silicon steel sheets with different gauges, TiN coating by the hollow cathode discharge (HCD) method was performed on polished very thin (0.10 mm) and thin (0.20 mm) silicon steel sheets. Domain structures of (011)[100] single crystals of silicon steel, which were chemical polished, TiN-coated and then domain refined by scribing with a knife at 4 mm widths perpendicular to the rolling direction, were observed by electron microscopy.
Very thin 0.10 mm TiN-coated silicon steel showed ultra-low iron loss of W13⁄50=0.12 W/kg after the domain refinement, whereas thin 0.20 mm TiN-coated silicon steel showed W13⁄50=0.26 W/kg.
The domain structures obtained by TiN coating and inducement of a small local strain by scribing produced a drastic domain refinement, and the variation in domain structure was more pronounced with thinner gauges. The variation in iron loss was consistent with the changes in domain structure.
It should be noted that the iron loss of the very thin 0.10 mm TiN-coated silicon steel, which was about 5 times as thick as amorphous FeSiB (0.02 mm thick), showed ultra-low iron loss comparable to that of the much thinner material.
