磁控溅射制备锌镍合金薄膜的结构及耐蚀性能研究

Study on Structure and Corrosion Resistance of Zn-Ni Alloy Films Prepared by Magnetron Sputtering

为提高飞机结构件的耐蚀性能,采用闭合场非平衡磁控溅射技术在18Cr3Ni结构钢表面制备了锌镍合金薄膜,考察了锌靶和镍靶电流对薄膜表面形貌、微观结构和耐蚀性能的影响。分别采用扫描电镜(SEM)、X射线衍射仪(XRD)和纳米压痕仪对薄膜的微观形貌、晶相结构和力学性能进行了分析。对薄膜的电化学特性和耐中性盐雾腐蚀性能进行了研究,并对腐蚀产物进行了分析。结果表明:采用闭合场非平衡磁控溅射技术制备的锌镍合金薄膜具有致密的结构,薄膜中的镍起到了细化晶粒的作用,但随着镍含量的增加,薄膜的耐蚀性能下降。镍含量为7.63%(原子分数,下同)的锌镍合金薄膜具有最好的耐蚀性能,但其力学性能较差;镍含量为12.88%的锌镍合金薄膜具有良好的耐蚀性能和力学性能。薄膜经过中性盐雾试验后的腐蚀产物Zn_(5)(OH)_(8)Cl_(2)·H_(2)O起到了钝化作用,阻止了薄膜和基底被进一步腐蚀。采用磁控溅射制备的锌镍合金薄膜可用于精密结构件表面的腐蚀防护。

For improving the corrosion resistance of aircraft structural components, zinc nickel alloy films were prepared on the surface of 18Cr3Ni structural steel using closed field non-equilibrium magnetron sputtering technology, and the effects of zinc and nickel target currents on the surface morphology, microstructure and corrosion resistance of the films were investigated. The microstructure, crystal structure and mechanical properties of the thin film were analyzed by scanning electron microscopy(SEM), X-ray diffraction(XRD) and nanoindentation apparatus, respectively. In addition, the electrochemical properties and resistance to neutral salt spray corrosion of thin films were studied, and the corrosion products were analyzed. Results showed that the zinc nickel alloy thin film prepared by closed field non-equilibrium magnetron sputtering technology possessed a dense structure. Besides, the nickel in the film played a role in refining the grain size, but the increase of nickel content could decrease the corrosion resistance of the film. The film with Ni content of 7.63%(atomic fraction, the same below) exhibited the best corrosion resistance, but poor mechanical performance. By contrast, the film with Ni content of 12.88% had excellent corrosion resistance and mechanical performance. The corrosion product Zn_(5)(OH)_(8)Cl_(2)·H_(2)O produced by the neutral salt spray test on the film had a passivation effect, preventing further corrosion of the film and substrate. In general, the zinc nickel alloy thin films prepared by magnetron sputtering could be used for corrosion protection on the surface of precision structural components.