固态NaCl诱导的TiAlN多层涂层热腐蚀行为研究

High temperature corrosion of TiAlN multilayer coatings by solid NaCl

采用高功率脉冲磁控溅射(HIPIMS)技术耦合多弧离子镀技术,在钛合金和304不锈钢基体表面沉积高致密TiAlN/Me多层纳米复合膜层,通过SEM、XRD、XPS等方法对涂层的宏微观结构进行表征,在500℃高温的固态盐膜环境下,研究不同金属子层种类对涂层高温热腐蚀能力的影响规律.结果表明:TiAlN/Ti多层涂层孔隙率低至0.049%,以点蚀为主要腐蚀形式的涂层热腐蚀面积占比为2.948%,分别达到304不锈钢和Ti-6Al-4V钛合金基体耐腐蚀能力的24.046和23.041倍.TiAlN/TiAl涂层由于涂层表面缺陷和层间缺陷分布广泛,涂层腐蚀面积占比达到67.090%.TiAlN/Ti比TiAlN/TiAl多层纳米复合膜层有更优的高温热腐蚀性能.

Protection of mechanical parts in marine high-salt environment is a difficult issue.Coating technology is an effective means to improve corrosion resistance of key parts.HIPIMS coupled with multi-arc ion plating technology were used to deposit TiAlN/Me multilayer coatings.Effects of metal tie-layer on thermal corrosion resistance of coatings were studied.Morphology and structure of coatings were characterized by SEM,XRD and XPS.Corrosion resistance was tested in air environment through a solid salt film at 500℃.TiAlN/Ti coatings were found to demonstrate super-low porosity and corrosion,being 24.046-and 23.041-fold more corrosion-resistant than304-steel and Ti-6Al-4V substrate respectively.Due to widely distributed defects in TiAlN/TiAl coating,relative corrosion area accounted for 67.090%.It is worth noting that titanium is more suitable for tie-layer within multilayer coatings than alloy TiAl,due to excellent surface roughness and low porosity.This is of vital importance to its high temperature corrosion resistance.