FORMATION OF MICRO-NANO STRUCTURE BY LASER DEPOSITION AND DEALLOYING OF COPPER ALLOY LAYER ON MACRO-COMPONENT SURFACE

摘要

Nano-alloys or nano-structure often display novel physical, chemical and mechanical properties. It is of great scientific and engineering meanings to deposit micro-nano structure on macro-component surface to locally achieve nano-properties for potential applications. Laser deposition offers a promising approach to deposit a designed structure with designed composition on any location of a component. This paper focuses on the formation of micro-nano porous structure by laser deposition and dealloying of copper alloy layer on macro-component surface. A MnxCu1-x powder mixture was laser deposited on steel substrates to obtain layers with exact composition by laser processing optimization and original power composition optimization. These layers were then dealloyed in electrolyte by both free corrosion and electrochemical etching of manganese component. Bicontinuous porous copper layer with porosity in size of about 700 nm was formed after electrochemical etching, while no porous copper layer could be obtained in free corrosion. Dilute ratio, chemical composition and microstructure of the alloy layers were investigated using SEM, X-EDS and XRD. The results indicate that porous copper layer could be obtained by integrating laser deposition with low dilute ratio and electrochemical dealloying.