低温AlCl_3-NaCl-KCl三元无机熔盐体系电镀铝工艺

Microstructure and Corrosion Resistance of Aluminum Coating Electroplated on Low Carbon Sled from Low-Temperature AlCl_3-NaCl-KCl Inorganic Molten Salt

用AlCl3-NaCl-KCl三元无机熔盐体系在Q235低碳钢基体上镀铝,运用涂层测厚仪、X射线衍射仪、金相显微镜、静态浸泡失重法等手段,对铝镀层的厚度、相结构、表面形貌和耐蚀性等进行了研究。结果表明:铝镀层厚度随电流密度的增加近似成线性增长,电镀前期随电镀时间延长明显增大,之后变化率逐渐减小;镀层为面心立方结构单相铝,主要由(200)面组成;铝镀层与碳钢基体结合良好,具有较好的耐蚀性能。

Electroplated aluminum coating was prepared on Q235 carbon steel from ternary inorganic molten salt AlCl3-NaCl-KCl.The morphology,thickness and micro-structure were analyzed by using an optical microscope,a coating-thickness gauge and an X-ray diffractometer.The corro-sion resistance of the Al coating was evaluated by measuring its weight-loss in static soaking at room temperature.Results show that the thickness of the Al coating increases approximately line-arly with extending plating time.Namely,the thickness signifi-cantly increased with extending plating time during the early stage of electroplating,then it increased at a lowered pace.The as-prepared Al coating,composed of small needle-like or granu-lar grains,was gray,smooth,uniform and had good adhesion to substrate and good corrosion resistance as well.