Si含量对镁合金表面铝基涂层摩擦学性能的影响

Impact of Silicon Content on Wear Behavior of Al-based Coating on the Surface of Magnesium Alloy

为提高镁合金的耐磨性能,采用超音速微粒沉积技术在ZM5镁合金表面喷涂,完成Al-12Si与Al-15Si耐磨防护涂层的制备。利用扫描电镜(SEM)与三维形貌显微镜对抛光后涂层的微观形貌与成分进行观察,通过X射线衍射仪(XRD)、金相显微镜与显微硬度仪对两种涂层的组织与显微硬度分析,用摩擦磨损试验机对涂层进行摩擦试验,并对两种涂层摩擦磨损试验产生的磨痕微观形貌进行对比。结果表明:Al-12Si涂层与Al-15Si涂层中主要为α-Al相和共晶组织,Al-15Si涂层的硬度为135.9HV0.05,高于Al-12Si的硬度(113.2HV0.05);且两种涂层均以粘着磨损为主要磨损失效形式。Al-15Si涂层在3种载荷下(10、20和30N)的磨损体积均小于Al-12Si涂层,Al-15Si涂层具有较强的耐磨性能,可以更好地为镁合金基材提供长效耐磨防护。

To improve the wear resistant properties of ZM5 alloy, Al-12Si, and Al-15Si coatings were prepared by supersonic particles deposition. The microstructure and chemical composition of the coatings after polishing were investigated and analyzed by scanning electron microscope （SEM）. Their structure and microhardness were studied by the X-ray diffraction （XRD）, optical microscope （OM） and the microhardness tester. Their wear scar morphologies that were made by the friction and abrasion testing machine were researched by SEM and three-dimensional microscope. The results show the main phases of Al-12Si coating and Al-15Si coating are α- Al and eutectic structure. The microhardness of A1 - 15Si coating and Al - 12Si coating is 135.9 HV0.05 and 113.2 HV0.05. In addition, the main abrasion failure mechanism of the two coatings is adhesive wear, and Al-15Si coating has the less volumes and the better anti-friction properties in the conditions of 10, 20, and 30 N. All those indicate that Al-15Si coating has the better anti-wear properties, which can provide long-time protection for ZM5 magnesium alloy substrate.