Z. Boukha

Laser texturization to improve absorption and weld penetration of aluminum alloys

In the present work, laser texturization treatments have been performed for the first time on aluminum alloys to increase their absorption and weld penetration. Adjusting the experimental conditions, laser texturization increases the roughness and decreases the diffuse and specular reflectance of surfaces. The textured samples were subsequently subjected to bead-on-plate laser weld treatments with a high power diode laser. Taking the weld beads of sandblasted samples as reference, depth improvements percentages around 20% are reached in some textured samples. Laser texturization has demonstrated to increase the weld penetration ability of aluminum alloys, constituting a potential tool to reduce the energetic requirements of the laser welding process.

Laser welding of aeronautical and automobile aluminum alloys

Laser beam welding (LBW) show clear advantages compared with other techniques, as the low heat input, the high localization ability, the high welding speed, the high flexibility, the high weld quality and the high production rate. However, its applicability to aluminum alloys is limited, as they generally have high reflectivity, high thermal conductivity and low viscosity. In the present study, it is analyzed the laser weldability of four aluminum alloys (2024, 5083, 6082 and 7075). High penetration butt welds could be obtained with a high power diode laser under conduction regime. The properties of the weld beads such as the microstructure and microhardness were analyzed. A linear function between the input laser fluence and the volume of melted material was obtained for the four alloys.

Application of Laser Remelting Treatments to Improve the Properties of Ti6Al4V Alloy

Ti6Al4V is the α-β alloy most employed in industry. The modification of its properties can be achieved with conventional heat treatments and/or with laser processing. Laser remelting (LR) has been applied to Ti6Al4V by other authors with excimer and Nd-YAG laser, employing pure argon as shielding gas to prevent risk of oxidation. In the present contribution, LR has been applied for the first time with a high power diode laser shielded with argon to improve the properties of Ti6Al4V. Results showed that remelted samples (with medium energy densities) have higher microhardness and better corrosion resistance than Ti6Al4V base metal.

Analysis of the Laser Weldability under Conduction Regime of 2024, 5083, 6082 and 7075 Aluminium Alloys

Laser beam welding (LBW) show clear advantages compared with other techniques, as the low heat input, the high localization ability, the high welding speed, the high flexibility, the high weld quality and the high production rate. However, its applicability to aluminium alloys is limited, as they generally have high reflectivity, high thermal conductivity and low viscosity. In the present study, the laser weldability of four aluminium alloys (2024, 5083, 6082 and 7075) under conduction regime is analysed. High penetration butt welds could be obtained with a High Power Diode Laser (HPDL) under conduction regime. The properties of the weld beads such as the microstructure and microhardness were analysed. A linear function between the input laser fluence and the volume of melted material was obtained for the four alloys.

Application of Laser Texturization to Increase the Depth of AA5083 Welds

The application of laser beam welding to aluminium alloys has some complications, mainly due to their high reflectivity, high thermal conductivity and low viscosity. In order to increase the laser absorption of aluminium alloys, some surface treatments has been applied in the literature, such as the application of dark coatings or sandblasting. However, these conventional superficial treatments have some drawbacks, such as the low weld penetration, the possibility to undergo magnesium evaporation and the impossibility to control and/or change the superficial properties of the treated samples. In the present contribution, laser texturization treatments have been performed with a fibber laser for the first time on aluminium alloys to increase their absorption and weld penetration. The texturised samples leaded to deeper bead welds than the reference sandblasted samples.

Laser remelting of Ti6AL4V using high power diode laser

Titanium alloys present excellent mechanical and corrosion properties, being widely employed in different industries such as medical, aerospace, automotive, petrochemical, nuclear and power generation, etc. Ti6Al4V is the α-β alloy most employed in industry. The modification of its properties can be achieved with convectional heat treatments and/or with laser processing. Laser remelting (LR) is a technology applied to Ti6Al4V by other authors with excimer and Nd-Yag laser with pure argon shielding gas to prevent risk of oxidation. In the present contribution, laser remelting has been applied for the first time to Ti6Al4V with a high power diode laser (with pure argon as shielding gas). Results showed that remelted samples (with medium energy densities) have higher microhardness and better corrosion resistance than Ti6Al4V base metal.

Improvements of laser weldability of aluminum alloys by laser texturization

The application of laser beam welding to aluminum alloys has some complications, mainly due to their high reflectivity, high thermal conductivity and low viscosity. In order to increase the laser absorption of aluminum alloys, some surface treatments has been applied in the literature, such as the application of dark coatings or sandblasting. However, these conventional superficial treatments have some drawbacks, such as the low weld penetration, the possibility to undergo magnesium evaporation and the impossibility to control and/or change the superficial properties of the treated samples. In the present contribution, laser texturization treatments have been performed with a fibber laser for the first time on aluminum alloys to increase their weldability. These textured samples have shown better weldability than reference sandblasted samples.