Determination of the conditions of nanoporous structures formation in metal materials by pulse-periodic laser treatment

Abstract

The influence of the laser treatment to create a nanoporous structure in copper-zinc alloy has beensearched. Laser treatment of pulse-periodic radiation enables to form a stable stress state on the sample surface ata temperature that does not exceed the melting point. The conditions of nano-pores formation mainly of thechannel-type with the depth of the area of nanoporous structure formation not less than 40-45 m has beenascertained. The re-searches of the surface layer structure of the copper-zinc alloy L62 after laser treatment haveshown that in the cross-section the pores are oriented from the surface to the deep of metal and the poresconcentration is decreasing with an increase of distance from the surface. The laser treatment creates ananoporous structure in the surface layer. Temperature and speed modes of treatment which mainly cause thechannel-type nanopores formation with a width ~100 nm, which form a nanoporous network, are determined.Likewise the vibration speed measurements of the samples were carried out. Regardless of the external laserexposure frequency the maximum values of the vibration speed occur at almost the same frequenciescorresponding to the natural oscillation frequencies, under such conditions the nanoporous structures are formed.Damping device application significantly reduces the vibration speed values. In this case, the formation of thenanopores in the metal material does not occur.