Preparation And Properties Of Close-cell Aluminum Foam Surface Coating

As a structural and functional composite material,the aluminum foam has excellent performances such as light weight,high specific strength,energy absorption and so on.As a result,the aluminum foam has a broad application prospect in various fields,such as aerospace industry,transportation,construction and other fields.All territories have put forward higher requirements for aluminum foam.Improving the defects such as poor corrosion resistance,low strength,hardness limit and expanding the scope of application of aluminum foam has become the emphasis of research.In this study,the coating was prepared on the surface of aluminum foam by electro-deposition.The parameters for the electro-deposition of Cu were optimized in order to increase the corrosion resistance and compressive properties of close-cell aluminum.Different values of deposition voltages and times were considered to vary the amount of deposited Cu.The surface morphology of coating was observed by scanning electron microscope,the corrosion resistance was studied using an electrochemical workstation,the compressive properties were evaluated by universal testing machine.The study show that,the coating was occurred to be more homogeneous and compact with increasing voltage in a certain range and beyond which,the coating quality decreased apparently.The corrosion resistance of aluminum foam increases with the increase of deposition voltage.The compression results show three experienced stages:elastic deformation stage,collapse deformation stage and densification stage.After the electro-deposition of Cu,the elasticity modulus was increased obviously and the platform stress was also increase,the energy absorption of unit volume also increased.Furthermore,the platform area was widened apparently.In addition,Cu-SiC nanocomposite coatings were electro-deposited in aluminum foams for further improving the mechanical characterization.Furthermore,close-cell aluminum foam was treated with micro-arc oxidation method for different electrical parameter and time.The results show that,With the increase of the voltage of micro-arc oxidation,the number of micropores in ceramic layer decreases,the pore size increases,the sediment increases and the coating roughness increases.The X-ray diffraction patterns show that the main components of the ceramic film are Al and Al₂O₃,indicating that the ceramic phase is mainly formed by the combination of aluminum and oxygen.The corrosion resistance of aluminum foam increased after micro-arc oxidation,and the corrosion tendency and rate decreased with the increase of voltage.The stress-strain curves of the micro-arc oxidation sample is similar with the matrix.The compressive properties of aluminum foams improved with the increase of oxidation time.