ZAlSi12Cu2Mg1微弧氧化过程中负向电压对陶瓷膜层形成的影响

Effect of Cathode Voltage in Micro-Arc Oxidation on Ceramic Coating Film of ZAISi12Cu2Mg1 Alloy

在交流条件下,采用硅酸钠电解液,通过调节不同的负向电压值,在ZAlSi12Cu2Mg1合金表面制得了微弧氧化陶瓷膜层。研究了不同的负向电压值对陶瓷膜层形成过程的影响。结果表明:负向电压从80 V到160 V变化时,氧化时间从5 min延长到65 min,膜层厚度从28μm增加到208μm,致密度从0.267 g/cm^3增大到1.048 g/cm^3,特别是微弧氧化第2阶段氧化时间,在负向电压为160V时持续了32 min,试样表面逐渐变粗糙;在电解液组成为NaSiO_3 8 g/L,NaOH 2 g/L,Na_2EDTA 2g/L下,适宜的正/负向电压值为480/140 V,获得厚度为166μm的膜层。XRD分析表明:陶瓷层主要由莫来石、α-Al_2O_3和γ-Al_2O_3以及氧化铝的非晶物质组成。

It is very important to research the effect of cathode voltage on the forming of ceramic coatings. Ceramic coatings on the surface of ZAlSi12Cu2Mg1 alloy were obtained in the silicate sodium electrolyte at different cathode voltage values under the alternating current conditions. The effect of cathode voltage value on forming of ceramic coating was investigated. The results show that while cathode voltage varies from 80V to 160V, the oxidation time increases from 5 to 65 min, the film thickness grows from 28 μm to 208 μm, insulated intensity increases from 0.267 g/cm^3 to 1.048 g/cm^3, and especially the second stage of oxidation time lasts 32 min when cathode voltage is 160 V. At the same time, the surface of samples gets rough gradually. For electrolytic solution consists of Na2SiO3 8g/L, NaOH 2g/L, Na2EDTA 2 g/L, the optimal anode/cathode voltage is 480/140 V, and the film thickness reaches to 166 μm. The ceramic coatings were analyzed by XRD. The result indicates that they are composed of Mullite, α-Al2O3 and γ-Al2O3 and amorphous phases of alumina.