Investigation On Mechanism of Ultrasonic Welding AZ31B / 5052 Joint With Laser Texturing On Mental Surface

The ultrasonic welding was carried out to improve the quality of dissimilar Al/Mg alloys joint. The effects of laser texturing on the microstructure and mechanism of AZ31B/5052 joint connected by ultrasonic welding were also investigated. A series of laser texturing experiments on Al alloy (5052) and Mg alloy (AZ31B) were performed to determine the process parameters and their ef-fect on ultrasonic weld quality, especially on weld strength. Little effect was attained by opti-mizing welding parameters in improving mechanical properties. Both welding parameters and different texture pattern were investigated to obtain good weld quality. The connection mecha-nisms of joints were discussed based on the analysis of weld interface morphology, microstruc-ture evolution. Mechanical analysis of particle and movement of material atoms were analyzed in the study to explain the connect mechanism. The results show that the better lock-interface and lager lap shear strength were attained by laser texture addition and optimal welding parameters. Compared with the untextured joint, swirling bonding interface was obtained after the laser tex-ture. The laser texture with grid pattern was found to raise the strength up to 26% higher maxi-mum tensile-shear load than the joints obtained with the untextured surface.

Influence of laser power in nanosecond laser texturing for a hydrophobic state on SS316L

The use of lasers in surface engineering has recently made significant progress. The hydrophobic surface is commonly studied because of the application in various fields, including vehicles, aerospace, biomedicine, etc. Since these laser methods require many combination parameters, such as laser power (P), frequency (ƒ), scan speed (ʋ) and laser beam diameter (D), the effect of the parameters must therefore be investigated to produce the hydrophobic condition. This research tries to relate the laser power with the morphological properties and contact angle of the SS316L surfaces. Samples are subjected to laser texturing with different laser power settings. The surface is then characterised by surface roughness, and the contact angle is measured according to a specific time interval. The laser power output and energy density function on the surface and contact angle were investigated in these contexts experimentally. Surface roughness was defined and validated to show that the laser parameters' effect is effective and controllable. This study shows that the laser output intensity significantly contributes to regulating surface roughness and the substrate's wetting activity. The 18W and 24W laser outputs produce a spiked surface with various peaks that cause the surface to become hydrophobic over time because of the air-trap that happens in the valley.

Modification of the copper wettability by nanosecond laser texturing

Nanosecond laser microstructuring of copper surfaces was performed in this work. The contact angle value immediately after laser treatment decreased sharply and all samples were hydrophilic or superhydrophilic. Hydrophobization of the textured samples occurs as a result of environmental exposure over time. Oxidation and adsorption of carbon and its compounds from the atmosphere leads to a change in the wettability of the irradiated surfaces. The acceleration of hydrophobization process with decrease of fluence was found. It is shown that the stable contact angle, reached after one month, does not depend on the value of the fluence and is about 140°.