The poliMATIC research project has received funding from the European Community´s 7th Framework Programme (FP7/2007-2013) in the call FP7-NMP-2009-SME-3
The "poliMATIC - Automated Polishing for the European Industry" project was successfully completed middle 2013. For further information please contact Dr.-Ing. Edgar Willenborg
Polishing with laser radiation is based on the remelting of a thin surface layer of the work piece and smoothing of the surface roughness due to the surface tension. The innovation of laser polishing results from the fundamentally different active principle (remelting) compared to conventional grinding and polishing (abrasion). For metals usually diode pumped solid state lasers are used. For surfaces with an already small initial surface roughness, e.g. after grinding, pulsed laser radiation with pulse durations of several 100 ns is used. Is the initial roughness higher, e.g. after milling or EDM-processing, continuous laser radiation must be taken. The remelting depth is in the range of several 100 nm for pulsed and up to 100 µm for continuous laser radiation.
Process Features and Advantages:
Automated processing of 3D surfaces and therefore
Polishing results independent of laborer
Suitable also for small and compex shaped parts
Short machining times especially in comparison to manual polishing
Selective polishing of limited areas
Polishing of milled, turned, grinded or EDM-processed surfaces
No pollutive impact from grinding and polishing wastes
Avoidance of contaminations of the material with abrasives
State of the art in tool and mould making is manual polishing with processing times often above 10 min/cm². Therefore this branch has a high demand for automated polishing techniques for complex shaped 3D surfaces. The roughness demanded is usually in the range of Ra = 0.05 to 0.3 µm.
On tool steels 1.2343, 1.2344 and 1.3207 with milled or EDM-processed surfaces with an initial surface roughness of Ra = 1-4 µm laser polishing can reduce the roughness down to Ra = 0.05 to 0.1 µm. The processing time is about 1 min/cm². But also other steels and cast iron can be polished. But the quality of the polishing result depends on the material and especially the homogeneity of the material.
The fundamentals of laser polishing have been investigated on predominantly flat surfaces. The treatment of first demonstrators with rotational symmetric and freeform surfaces affirmed in general that laser polishing offers the potential of overcoming the current drawbacks in surface finishing but also revealed the need for research and development. In poliMATIC laser polishing will be further developed to a reliable manufacturing process.