电脉冲沉积铝化物微晶涂层的高温腐蚀行为

High temperature corrosion behavior of microcrystalline aluminide coatings by electro-pulse deposition

采用自行设计的振动式电脉冲沉积装置在Q235钢表面沉积厚度达100μm的铝化物微晶涂层,并研究涂层的高温腐蚀行为。采用振动式电脉冲沉积技术沉积涂层时,铝电极与工件瞬时接触放电,可以达到很高的温度,从而形成了铁铝金属间化合物涂层,而且涂层与基体为冶金结合;涂层冷却速度很快,由此获得微晶结构涂层;流动的氩气可有效地保护涂层的质量。将沉积铝化物微晶涂层的Q235钢分别在600℃空气中氧化200h和600℃99.98%SO2气氛中硫化50h,然后进行SEM、EDS和XRD分析。结果表明,沉积铝化物微晶涂层后Q235钢的抗氧化和硫化性能均大幅度提高。

Vibrating electro-spark deposition equipment is developed to prepare metal coatings with high deposition efficiency. An Fe-A1 intermetallic compound layer is formed by the high temperature plasma during the instant discharge between A1 electrode and specimen. The coatings formed on Q235 steel possess microcrystalline structure, with a thickness about 100μm. The micro-crystal line structure is achieved due to the high cooling rate during deposition. The quality of the coatings is enhanced by using Ar to protect samples from oxidation. The coatings are metallurgically bonded to the substrate without obvious interface. The samples with aluminide coatings for oxidation were put in air at 600 ℃ for 200 h, and those for sulfuration were put in flowing 99.98% SO2 at 600℃ for 50 h, and then SEM, EDS and XRD analyses were performed to understand the oxidation and sulfuration mechanisms of the coatings. The results show that the high temperature oxidation and sulfuration resistance of samples with aluminide coatings are improved remarkably.