Excimer laser interactions with an aluminum alloy

Abstract

An AlCuMg alloy was irradiated using a KrF pulsed excimer laser. A microstructural study showed the presence of a laser treated zone having a uniform depth of approximately 20 μm. The surface layer of the laser treated aluminum alloy exhibited a wavy topography and its surface roughness was found to depend on the number of laser pulses per step. A X-ray diffraction analysis revealed the presence of aluminum oxides and nitrides on the surface of the laser irradiated specimens. Corrosion measurements showed that the laser treated aluminum alloy exhibited a higher corrosion resistance. The corrosion behavior of the irradiated specimens is related to the energy density of the incident laser pulses.

Grain structure and homogeneity of pulsed laser treated surfaces on Al-aerospace alloys and FSWs

“…In the second regime the layer solidified with a fine cellular structure, growing upwards-parallel to the thermal gradient, which coarsens with the layer thickness. To date, layers below this thickness have been reported as being 'homogeneous', which has been linked to a substantial improvement in corrosion resistance [3,[5][6][7][8][11][12][13][14][15]. To prevent the formation of a cellular structure throughout the layer on resolidification, and ensure a reasonable chance of obtaining a chemically homogeneous layer, the melt depth is thus restricted to less than ∼10 m in thickness.…”

“…Recently, several studies have been reported demonstrating dramatic improvements in corrosion performance that can be gained from pulsed laser surface treatments of aluminium alloys and welds made in aerospace materials [3,[5][6][7][8][11][12][13][14][15]. In all of these publications emphasis has been placed upon characterisation of the treated surfaces improved corrosion behaviour, with less attention paid to the microstructural changes in the subsurface layer that underpin these changes.…”

Surface engineering of aluminium and titanium alloys: An overview

“…47 Few investigations are carried out on laser nitriding of aluminium alloys in solid state. [48][49][50] Laser nitriding of aluminium alloys in liquid state was investigated by Bergmann and co-workers. [51][52][53][54] They produced by laser gas nitriding on technical alloys crack free, dense, AlN containing gradient surface layers with a thickness up to 20 mm.…”

Effect of laser formed AlN/Al2O3 films on corrosion behaviour of aluminium alloy 6013

“…With the extremely short pulse duration (typically ,20 ns) and high energy per photon of the excimer lasers, some remarkable surface modifications can take place. In fact, Al 2 O 3 and AlN phases 7 in the form of adhered films were detected in the resolidified surface layer of aluminium alloys after excimer laser treatment in a nitrogen environment. 8 However, the structure of the surface film has not been studied in detail and its effect on corrosion properties has not been unequivocally determined.…”