Mechanical Joining of Glass and Aluminium

Abstract

The ongoing trend of miniaturization and increasing function integration makes it necessary to join different sheet materials in the micro range. Conventional joining processes cannot be scaled down to smaller dimension due to so called size effects. Thermal based joining processes, like welding or brazing can lead to distortion, which are more critical in the micro range. Normally ceramic materials can only be joined using extra joining elements like glue or bolts. Laser shock joining is a promising mechanical joining process for delicate material combinations. This process usesTEA-CO2-laser induced shockwaves. Several pulses are applied at one point to achieve high forming degrees without increasing the energy density beyond the ablation limit. The laser irradiates on the forming sheet and creates a plasma plume above the surface, which leads to a shockwave. This shockwave pushes the material in the joining area and creates an undercut which presents the joint itself. The laser induced shockwave is used to create an undercut underneath the other material. The form closure between the two materials enables a joint. So far, investigations were performed to identify the process window and the joining strength for aluminum and steel joints. The influence of die sheet materials is negligible, so that this process can be used for joining of dissimilar materials like aluminum and glass. Therefore, in this paper the suitability of this process for the mechanical joining of aluminum and glass is investigated. It is found that the tools need to be adjusted for the joining process. It is shown that a mechanical joining of aluminum and glass is possible. The joining strength is 53% of the theoretical maximum of the material strength of the aluminum. The limiting factor is the strength of the glass, which is breaking during the tensile tests.