Laser Welding Benefits Device Fabrication

This article compares and contrasts the capabilities of laser welding versus GTAW for medical device fabrication. It is intended to provide product development engineers some specific guidance on when and how to utilize the technology to save money and optimize results during production. Laser Welding versus GTAW In GTAW, two pieces of metal are first brought into contact or close physical proximity. A high voltage is established between a tungsten electrode and the workpieces, creating an arc that melts the materials. This melted material flows together and then subsequently resolidifies to form the weld seam. GTAW can use filler material to close any gap between the workpieces, or it can be performed autogenously (without filler). GTAW also uses argon shield gas to prevent oxidation of the electrode and the melted material. In laser beam welding (LBW), a focused, high-intensity laser spot is used to melt the material (instead of an electrical arc). Just as with GTAW, filler material is sometimes used, and an inert shield gas is often present. However, there are actually two distinct regimes of LBW, namely, conduction and keyhole welding. In keyhole welding, the laser is focused so as to achieve a very high power density (typically at least 1 megawatt/cm²) at the work piece. At the center of the focused beam (where the laser power density is usually highest), the metal actually vaporizes, opening up a blind hole (the keyhole) into the molten metal pool. This enab...
Source: MDDI - Category: Medical Devices Authors: Tags: Manufacturing Equipment Source Type: news