Secondary finishing processes in metal Additive Manufacturing

Secondary finishing processes in AM
Secondary finishing processes in AM

Comparison of AM medical device after shoot peening (top) and after vibratory grinding (bottom)

 

In order to achieve the necessary specifications or improve properties such as surface quality, geometrical accuracy and mechanical properties, it is often necessary to post-process and finish components produced with Additive Manufacturing techniques.

The usual surface roughness values for selectively laser melted metal parts vary between 15 µm and 40 µm (Rz in X/Y direction). Most physical characteristics can be enhanced by adding well-established fabrication processes at the end of the AM process chain.

The high quality of metal products produced using AM processes enables the use of many metal-machining finishes to meet the requirements of surface quality and geometry.

Following removal of support structures to separate the parts from the build platform, the products can be milled, drilled, polished, etc. Internal surfaces, such as those in internal/tempering channels for example, can be polished using abrasive flow machining.

Heat treatment is often included in the process chain as well as shot peening which is used to improve the mechanical and tactile properties of the surface of AM parts.

Another post process of interest is electro polishing, as this electrochemical treatment significantly improves the surface finish of AM parts. Its first objective is to minimise micro roughness, thus reducing the risk of dirt or product residues adhering and improving the cleanability of surfaces. However, electro polishing can also be used for deburring, brightening and passivating, particularly for surfaces exposed to abrasive media. Since electro polishing involves no mechanical, thermal or chemical impact, small and mechanically fragile parts can also be treated.

 

> Next page: Properties and standards

Download the latest issue of Metal AM magazine

Our latest issue is now available to view online or download in PDF format.

As well as an extensive AM industry news section, this 196-page issue includes articles and reports on:

  • Sintavia: New facility signals the move towards volume metal Additive Manufacturing for aerospace and defence
  • Thinking about metal Binder Jetting or FFF? Here is (almost) everything you need to know about sintering
  • Metal Binder Jetting and FFF: Considerations when planning a debinding and sintering facility for volume production
  • Velo3D: How a ‘support-free’ Laser Powder Bed Fusion process could remove roadblocks to serial Additive Manufacturing
  • New horizons for Additive Manufacturing in the oil, gas and maritime industries
  • Redesigned for Additive Manufacturing: Serial production of a new fuel swirler for Siemens gas turbine
  • Understanding metal powder requirements for Additive Manufacturing: Views from the industry
  • Towards a true digital twin for the metal Additive Manufacturing process
  • > More information

Latest news

    E-newsletter

    Sign up to our e-newsletter, sent weekly to AM professionals and end-users around the world. We'll also let you know each time a new issue of Metal AM magazine is available.

    Discover our magazine archive…

    The free to access Metal Additive Manufacturing magazine archive offers unparalleled insight into the world of metal Additive Manufacturing from a commercial and technological perspective through:
    • Reports on visits to leading metal AM part manufacturers and industry suppliers
    • Articles on technology and application trends
    • Information on materials developments
    • Reviews of key technical presentations from the international conference circuit
    • International industry news
    All past issues are available to download in PDF format, in either single page format or as double-page “spreads” for viewing on large monitors. All downloads are free of charge. Go to archive...

    Connect with us

    Visit our social media channels and sign up to our e-newsletter