Co-Mn尖晶石涂层的制备

Preparation of Co-Mn Spinel Coatings on 304 Stainless Steel Plate

采用氯化物溶液在430不锈钢表面电沉积Co-Mn合金,重点研究了镀液pH值和电流密度对镀层微观结构及成分的影响。结果表明:pH值为2.5~6.5、电流密度为125~225mA/cm2时,镀层中的Mn含量随着pH值和电流密度的增大而增加;电流密度为125和175mA/cm2时,pH值是决定合金成分的主要因素,电流密度达到225mA/cm2时电流密度是影响合金成分的主要因素;电镀Co-Mn合金的优化工艺参数为pH值为4.5、电流密度为125mA/cm2,此时镀层质量良好,Mn含量可达20%(原子分数)以上;通过除氢处理及在800℃空气中的氧化处理,合金镀层转变为连续、与基体结合良好的MnCo2O4尖晶石涂层。

Co-Mn alloy coatings can be prepared on 304 stainless steel with a chloride containing bath, while the effect of pH value of the electrolyte and the applied current density on the microstructure and composition of the coatings was investigated. The results indicated that the Mn content in the coatings increased with either increasing pH value or current density in a pH value range of 2.5 to 6.5 and a current density range of 125 to 225 m A/cm2 respectively. The pH value was the main factor determining the composition of Co-Mn alloys when the current density was of 125and175 m A/cm2, while the current density turned to be the main factor when it reached up to 225 m A/cm2. A smooth, dense and uniform coating with Mn content above 20%(atomic fraction) could be obtained by p H value of 4.5 and current density of 125 m A/cm2. After a hydrogen- relief treatment and then an oxidation treatment at 800 ℃, the electroplated Co-Mn alloy coating might be transformed into a continuous Mn Co2O4 spinel oxide film with a good compatibility to the substrate.