By: Dr. Ingomar Kelbassa
Laser Surface Treatment and Additive Manufacturing have a strong impact on classical manufacturing and repair tasks addressing markets such as turbo machinery, aeronautics, automotive, off-shore and mining as well as tool, die, and mold making and life science.
Laser Cleaning is an industrially implemented non-contact process providing the possibility to clean dirty and/or rusty surfaces of e.g. vulcanizing tools and pylons without negative effects resulting from other alternative cleaning processes such as mechanical cleaning (surface finish destroyed) and/or chemical cleaning (pollution). Injection molds can be cleaned without being cooled down and in an assembled state. In public places, Laser Cleaning is an established process to clean older monuments and buildings.
As being the newest development in Laser Surface Treatment, polishing times for parts made from metals such as Fe and Ti base alloys and glasses can be decreased by factors of 10 up to 100 accompanied by a significant increase of reproducibility compared with manual polishing. Laser Polishing is used for finishing freeform surfaces of fine mechanics parts such as micro parts of mechanical watch movements, tools, dies, and molds as well as medical parts such as components of artificial hearts and implants.
Laser Heat Treatment offers the possibility to carry out local heat treatments with specific temperature-time-cycles to adjust the macro and micro structures of materials e.g. resulting in increased – hardening – or decreased – softening – strength of the part. Application examples are the selective hardening of linear guides and the selective softening of high strength steels aiming for a significant decrease of the forming force of approx. 25 % when forming sheet metals. Another important use for Laser Heat Treatment is the process support for Laser Materials Processing and Machining in general such as preheating or post weld heat treatment. Exemplary, turbo machinery parts undergo an appropriate post weld heat treatment after having been repaired via Laser Metal Deposition to adjust the micro structure and hence, the mechanical properties of the part.
Laser Additive Manufacturing (LAM) of parts and components by Laser Metal Deposition and Selective Laser Melting fascinates due to process specific advantages such as nearly unrestricted geometrical freedom, material freedom, and achievable properties of the parts built-up. The in layers build-up offers the possibility to manufacture components with graded physical, chemical, and mechanical properties. Hence, tailored parts and components can be manufactured, repaired, and modified by LAM. Near-net-shape LAM techniques offer new opportunities with regard to a sustainable protection of (material and energy) resources due to a very high material efficiency (recycling etc.) and very low energy consumption in comparison to conventional primary shaping techniques such as casting, and subsequent finishing operations such as milling and forging. Laser Metal Deposition is established in nearly every market for e.g. wear and corrosion protection, local repairs, and additive manufacture of entire, high-valued parts (Picture: Laser Metal Deposition for local repair of aero engine parts) whereas the advantages of Selective Laser Melting become crucial in case of an aimed serial but high individual production such as in medicine – additive manufacture of e.g. crowns, bridges, and implants in dentistry.
Future developments in the field of Surface Treatment and Additive Manufacturing cover new materials such as Metal Matrix Composites, intermetallics, and ceramics as well the improvement of process efficiencies towards higher processing speeds to address economics.
