Laser Beam Build-Up Welding: Precision in Repair, Surface Cladding, and Direct 3D Metal Deposition

摘要

Surface coating, repair, and rapid design changes of high-value components and tools are demanding challenges of modern manufacturing technology. In this field, advanced laser-based techniques are of outstanding importance for the related applications in mould and tool, aircraft and aerospace, as well as automotive industry. Many laser cladding solutions have been transferred into industrial series production within the last years. The motivations for the raising interest are given by the typical features of the technology: on the base of closed CAD/CAM chains, a quick and comprehensive treatment even of complex shaped and highly stressed components is possible. The heat input into the workpiece is less compared to TIG or PTA welding, although a metallurgical bonding to the substrate is guaranteed. Furthermore, the precise material deposition even at small partial areas is an advantageous characteristic. The coating materials include metal alloys (Co, Ni, Cu basis, Titanium, and steel), hard metals (e.g., WC/Co, TiC, and VC with metallic binders), and oxide ceramics (Al{sub}2O{sub}3/TiO{sub}). Typical base materials are steel, cast iron, and lightweight metal alloys based on Aluminum, Titanium, and Magnesium. The accuracy of the produced 3D structures in the range of 0.1 mm is the highest possible in the group of welding techniques. On the other hand, the available system technology (lasers, powder feeders and nozzles, CAD/CAM systems) permits a very easy and successful integration of the laser technology into manufacturing systems. Examples of application are the surface protection of lightweight automotive motor components, repair and quick modifications of metal forming tools as well as the complete restoration of damaged blades and disks of aero engines and gas turbines.