Surface Finishing

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Partner

This post processing study was realized in cooperation with Walther Trowal GmbH & Co. KG, a company specializing in grinding technology based in Haan.

FIGURE 1 Component on building plate after sand blasting Bild vergrößern
FIGURE 2 Component after final surface finish through vibratory grinding Bild vergrößern

Objectives

The surfaces of additive components are not as smooth as for conventional machined parts due to the manufacturing process. Therefore, AM manufactured components require a surface post treatment. Due to the complex geometries of AM components with undercut and difficult to reach areas, conventional machining like drilling or milling are not suitable as overall surface treatments. Even sand blasting often does not meet the requirements. In cooperation with Walther Trowal the vibratory finishing technique was investigated as a surface treatment for additive manufactured components. This offers attractive possibilities for improving the surface.

Procedure

Walther Trowal has developed various processes and special machines for subsequent surface treatment. The Direct Manufacturing Research Center at Paderborn University has provided various components with hard-to-reach areas and narrow cross-sections. These are treated by vibratory grinding for a period of around 24 hours. The polishing and treatment additives developed at Walther Trowal are specially selected for the materials to be prepared.

Archievements

After the treatment, the surface quality of the components is outstanding. Even very narrow and hard to reach areas have a smooth surface. The process is also used by many well-known companies for difficult-to-machine materials such as titanium and cobald chromium alloys. The process is characterized by high quality and reproducibility, which makes it attractive for other applications.