钨酸钠对取向硅钢绝缘涂层性能的影响

采用扫描电镜、爱波斯坦方圈、绝缘电阻测试仪、红外光谱仪和热分析仪等手段研究取向硅钢绝缘涂液中钨酸钠对制备的磷酸盐绝缘涂层微结构和性能的影响。结果表明:随着钨酸钠含量的逐渐增加,涂液与取向硅钢基底的润湿角先减小后增大;取向硅钢的层间电阻、叠装系数和磁感应强度均先增大后减小,铁损先减小后增大。当钨酸钠含量为2.0%(质量分数)时,涂液与硅钢基底的润湿性能最好,润湿角为39.3°;涂层致密、平整,绝缘涂层与硅酸镁底层之间存在0.8μm左右的过渡层,而且涂层的耐吸湿性能并不产生显著变化;取向硅钢的层间电阻、叠装系数、磁感应强度和铁损均达到最佳值,分别为14073Ω·mm~2,97.0%,1.893T和1.051W·kg~(-1)。

Effects of Sodium Tungstate on Properties of Insulation Coating for Grain-oriented Silicon Steel

The effect of sodium tungstate in insulation coating solution of grain-oriented silicon steel on the microstructure and properties of the prepared phosphate insulation coating was investigated by using scanning electron microscopy (SEM), Epstein square, insulating resistance tester and Fourier transform infrared spectrum (FTIR) et al. The results show that, with the gradually increasing content of sodium tungstate in the coating solution, the wetting angle between the coating solution and the grain-oriented silicon steel substrate first decreases and then increases; the interlamination resistance, lamination factor and magnetism induction intensity of grain-oriented silicon steel first increase and then decrease, the iron loss first decreases and then increases. When the sodium tungstate content is 2. 0％ (mass fraction), the coating solution shows the best wettability on the grain-oriented silicon steel substrate, the wetting angle is 39. 3°; at the same time, the formed insulation coating is dense and smooth, there is a diffusion area about 0. 8μm at the junction between the insulation coating and the magnesium silicate bottom layer, furthermore, the humidity resistance of the insulation coating is not significantly changed; the interlamination resistance, lamination factor, magnetism induction intensity and iron loss of grain-oriented silicon steel reach the optimal values, which are 14073() · mm2, 97. 0％, 1. 893T and 1. 051W · Kg-1,respectively.