Preparation And Mechanical Properties Of Nanoporous Copper Films

As a new functional nano-material,nanoporous copper film has many novel physical and chemical properties due to its ultra-high specific surface area and surface activity,which has shown extraordinary application potential in the fields of new energy,catalysis,filtration and separation,etc.Magnetron sputtering method is utilized to prepare alloy precursor and dealloying method is to establish a stable method for preparing ultra-fine and high-purity nanoporous copper films.We used nanoindentation method to test its mechanical properties and dimensional analysis method to characterize the stress-strain relationship of nanoporous copper films.These works can provide to theoretical and experimental basis for the practical application of nanoporous copper films.The specific research in this paper can be summarized as follows:(1)Monocrystalline silicon and copper are selected as substrate materials to investigate the effects of different film/substrate structures on the preparation of nanoporous copper films.We found that the bonding force between copper substrate and Cu-Al film is much stronger than that of silicon substrate.This advantage makes it possible to prepare porous copper films with a copper atom ratio of over 96%and ligament size of about 30nm from the alloy precursor based on copper sheets.(2)The influence of Cu-Al alloy precursors with different atomic ratios and corrosive environment on the structure,ligament size and pore size of nanoporous copper films are studied in detail.Then we have determined the atomic ratio interval of Cu and Al,the corrosion time interval and the concentration interval of the corrosion solution in the precursor of Cu-Al alloy suitable for corrosion by acid and alkali solutions respectively.(3)The mechanical properties of the prepared nanoporous copper film were tested by nanoindentation.The results show that nanoporous copper films with stable macro-mechanical properties can be obtained by the preparation method proposed in this paper.(4)Based on the experimental data and results computed via finite element method,we obtained the macro stress-strain relationship of the prepared nanoporous copper film by dimensional analysis.