Formation of nanoporous structures in metallic materials by pulse-periodic laser treatment

Abstract

Abstract A method of the formation of nanoporous structures in metallic materials by pulse-periodic laser treatment was developed. In this study, the multicomponent aluminum–iron brass was considered and the nanoporous structure across the entire cross section of the material with a thickness of 50 µm was formed. The method was implemented using a CO2 laser processing unit. The pulse-periodic laser treatment of the Cu–Zn–Al–Fe alloy with pulse frequency of 5 Hz has led to the formation of nanosized cavities due to accumulation of internal stresses during cyclic heating and cooling at high speeds. It was determined that the pores of a channel type with average widths of 80–100 nm are formed in the central region of the heat-affected zone during laser action with thermocycling. When implementing the chosen conditions of the pulse-periodic laser processing, the localness in depth and area of the physical processes occurring in the heat-affected zone is ensured, while maintaining the original properties of the material and the absence of significant deformations in the rest of the volume. This patented process is perspective for the production not only catalysts for chemical reactions, but for ultrafiltration and microfiltration membranes as well.