Laser treatment toughens machining dies

11 Dec 2013

Lifetime boosted by 150%, automotive manufacturing processes improved.

Laser treatment of forming dies, such as are used in the manufacture of automobile parts, makes them more robust and resistant to wear, an industrial R&D partnership has found. Using a laser to alloy surfaces with filler material can increase the service life of dies by 150%.

The results of research and development by the Fraunhofer Institute for Production Technology (IPT), Aachen, Germany, toolmaker Mühlhoff Umformtechnik and others involved in the Green Carbody Technologies Innovation Alliance (InnoCaT) were first demonstrated last week at the EuroMold trade show in Frankfurt.

Pressing dies for such manufacturing applications are costly, usually one-of-a-kind items made from special raw materials. Even dies just a few centimeters in size cost up to €600. So to keep costs down, manufacturers need to increase the lifetime of dies while reducing set-up times. The InnoCaT project concluded that a good method is laser-metal deposition. The laser precisely melts the surface of the die and suitable filler material to produce a local layer that will guard against wear on the die’s surface.

This process increases the robustness and resilience of the stainless steel die at critical points. The laser treatment is completed in fractions of a second. The Fraunhofer IPT explained that what has been lacking until its recent breakthrough, has been a universal, reproducible process for practical industrial use.

Lifetime up by 150%

The researchers rebuilt a conventional five-axis milling machine so that it could be used to alloy forming dies automatically by laser. The machine can be embedded into the current manufacturing process and besides increasing die lifetime by over 150%, the process also improves the quality of components and allows for planningh set-up times with greater precision, as practical tests carried out on Mühlhoff’s premises have shown.

Mühlhoff manufactures sheet metal components for the automotive industry. The company’s own toolshop supplies its various production locations with forming dies.
In addition to the laser metal deposition machine, another key part of the system is the integrated computer-aided design software.

The software allows all the requisite laser surface treatment processes to be controlled in a clear, reproducible manner. All necessary process parameters are transmitted to the machine without the need for any interface. Processes can be simulated in detail and optimized in advance of actual processing operations.

In 2010, over 60 partners from industry and research joined together in InnoCaT® with the aim of carrying out joint research into innovations and synergies along the automotive process chain. For the first time, they analyzed the complex production flows in their entirety and from a resource efficiency perspective, taking in each stage from tool-making to pres- sing, car body construction, and painting car body shells.

Five collaborative projects and 30 sub-projects yielded technical solutions and general approaches for increasing energy and resource efficiency before the initiative concluded in summer 2013.



About the Author

Matthew Peach is a contributing editor to optics.org.