镁合金表面磁控溅射沉积铝膜的力学性能

采用直流磁控溅射法在镁合金上沉积铝膜,在高真空下对铝膜进行加热后处理.用X射线衍射仪(XRD)分析膜层为纯铝多晶态,扫描电子显微镜(SEM)观察铝膜晶粒细小.采用纳米压痕/划痕仪对铝膜的厚度、临界附着力、硬度和弹性模量进行了测试,并且用辉光放电光谱仪(GDS)测试了镁合金表面铝膜的成分和性能随薄膜深度的分布.结果表明,铝膜的厚度随后处理温度的升高而降低,其表面硬度和弹性模量高于镁合金基体并且随深度增加而逐渐降低.铝膜与镁合金基体间存在一个过渡层,结合良好且表现出一定的弹塑性能,有利于镁合金表面的防护.

Mechanical properties of aluminum films on magnesium alloys by magnetron sputtering

A pure Al film was sputtered by DC magnetron on AZ31B magnesium alloy and heat-treated in a high vacuum. It was determined by the analyses of SEM and XRD that the Al film was ultra-fine polycrystalline. The thickness, critical adhesive force, hardness and elastic modulus of the Al film were measured by nano-indentation/scrateh test; the composition profile and properties were tested by glow discharge spectrometry (GDS). The results show that the thickness of the Al film decreases with increasing heat treatment temperature. Compared with the magnesium alloy, the Al film has a higher surface hardness and elastic modulus which decrease with increasing depth. A transition nano-scale layer forms between the Al film and substrate, which is of adherent trait and reveals somewhat elastoplastic property. It is concluded that the magnesium alloy can be protected by the Al film.