直流偏压对铝合金表面高功率脉冲磁控溅射沉积钒薄膜耐蚀性的影响

Influence of DC Bias on Corrosion Resistance of Vanadium Films on Aluminum Fabricated by High Power Pulsed Magnetron Sputtering Method

采用高功率脉冲磁控溅射(HPPMS)法,在工业纯铝基体上生长得到V薄膜,研究不同直流偏压对薄膜相结构、形貌及不同温度处理对耐蚀性的影响。结果表明,薄膜相结构为单一的V(111)相。薄膜表面光滑、平整,且随偏压的增大,薄膜表面粗糙度先减小后增大,最小仅为0.488nm。薄膜沉积过程中离子吸引效应和溅射效应的竞争导致薄膜沉积速率随着偏压的增大先减小后增大。20℃时镀V薄膜样品在偏压为-100V时耐蚀性最佳,其腐蚀电位比基体提高了0.425V,腐蚀电流下降了2个数量级以上。镀V薄膜样品经过200和300℃加热处理后,其耐蚀性提高,但是与基体相比,经200℃处理后的镀V薄膜样品腐蚀电流最大降低了1个数量级,而经300℃处理后的镀V薄膜样品耐蚀性与基体相比提高并不明显。

Vanadium films were fabricated on industrial pure aluminum using High Power Pulsed Magnetron Sputtering （HPPMS）. The influences of DC bias on phase structure, surface morphology, and especially the corrosion resistance of vanadium films after annealed at different temperatures have been investigated. XRD patterns show the highest intensity of V（111） preferential orientation. The surface of vanadium films was smooth and flat with a maximum roughness of 0.488 nm. The surface roughness decreased with increasing bias and increased if the bias further increased. The deposition rate decreased and increased with increasing sample bias. The reason is that ion attracting effect and sputtering effect competed in the deposition process. The sample treated at -100 V possessed the best corrosion resistance with the corrosion potential increased by 0.425 V and the corrosion current decreased by two orders of magnitude compared with the substrate. The samples exhibited much better corrosion resistance after annealing. The corrosion current of the samples annealed at 200℃ decreased by an order of magnitude compared with the substrate. The corrosion resistance of vanadium films increased less obviously compared with the substrate after annealing at 300℃.