In order to clarify the influence of the pre-treatment on the magnetic properties of TiN-coated silicon steel sheets, various acid treatments on the silicon steel sheets were done prior to the TiN coating by the HCD method.
With chemical polishing prior to TiN coating, the iron loss
W17⁄50(W/kg) of the TiN-coated silicon steel sheets was dramatically improved by 0.20-0.24 W/kg. In contrast, with the pre-treatments with 10%H
2SO
4 and 10%HCl solutions, the improvement of
W17⁄50(W/kg) was reduced to 0.1-0.14 W/kg. Also, the improvement of
W17⁄50(W/kg) in the pre-treatment with the H
2SO
4 solution was less than that with the HCl solution.
By the pre-treatments with 10%H
2SO
4 and 10%HCl solutions, the value of
W17⁄50(W/kg) became lower than that of a silicon steel product, but by subsequent TiN coating both We and Wh were improved. However, the improvement of
W17⁄50(W/kg) due to the pre-treatment with these acid solutions showed 60-70% of that in the case of chemical polishing.
The thin-film X-ray diffraction in the 111 peak intensity of TiN became weaker in the order of chemical polishing, the 10%HCl solution and the 10%H
2SO
4 solution, and in the latter case showed 200, 220 and 311 peaks of TiN.
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