Researchers improve accuracy of 3D printed metal parts with electric current

As metal additive manufacturing grows, it is not always easy to obtain high quality, high precision parts for specialized and demanding applications. That’s why a team of researchers at Saarland University in Germany has developed a non-contact process based on electrochemistry to transform metal 3D printed parts into complex components with dimensional tolerances of a few thousandths of a millimeter. A method that should make it possible to make greater use of end-use parts made in sectors such as aerospace or automotive.

The demand for metal parts in industrial sectors is strong and must meet precise requirements such as dimensional accuracy. Aircraft, car and rocket engines are usually made up of several parts that are assembled together and it is essential that each of them can withstand high mechanical stress. Today, metal additive manufacturing makes it possible to simplify the design process by reducing the number of components that make up a part, or by increasing its complexity. But it remains a difficult technology to master and achieving the same mechanical characteristics as a machined part is not easy, especially in terms of dimensional accuracy. 3D printing remains a “layer by layer” technology and it is not uncommon for these to be apparent.

Precision machining is the speciality of researchers Dirk Bähre (left) and Stefan Wilhelm, his technical assistant | Credits: Oliver Dietze

For this reason, Professor Dirk Bähre and his research team have developed a non-contact method for post-processing 3D printed metal parts. In concrete terms, they relied on electrochemical machining, a method of removing metal by an electrochemical process. The professor explains: “Electrochemical material removal makes it possible to create even the most complex geometries in the hardest metals. Our non-destructive, non-contact manufacturing technology allows us to efficiently machine parts with complex geometries, even if they are made of high-strength materials.”