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Post-Processing This Happens After 3D Printing
Post-processing is often forgotten when purchasing a machine for additive manufacturing. But it is an important process and by no means negligible. It is carried out in several steps, manually or semi-automatically.
Following the design and one or two misprints, the faultless printed component finally comes out of the machine. But now the work begins. "Every additive component requires some form of finishing," says Ralph Mayer, Sales & Business Manager AM at Renishaw. The company's additive machines use the SLM process, i.e. metal powder. "Reworking is necessary because the component is always welded to the substrate platform," Mayer concretizes his statement. "The component must therefore at least be separated mechanically. In addition, fits and functional surfaces must always be machined." That is why Renishaw uses conventional machining methods such as blasting or electrochemical treatment and polishing after powder bed printing.
An increasing number of companies is turning to powder removal and surface treatment. “Surface properties can quickly become an important topic, especially for applications in highly complex and highly stressed areas," says Matthias Schmidt-Lehr from the consulting firm Ampower. The company has identified five main reasons for surface treatment: aesthetic visible surfaces, better fatigue properties, better friction properties, reduced frictional resistance and surface preparation for subsequent coatings and improved corrosion protection. The greatest challenge for surface treatment is the extreme dependence on geometry. "One cannot expect a single process to deliver the best surfaces, but it will rather depend on the application," explains Schmidt-Lehr. Ampower is currently preparing a study on post-processing in additive manufacturing. It is due to be published at the beginning of 2020.