The quality of metal powder is a crucial factor for reliable additive manufacturing (AM) using laser powder-bed fusion (LPBF) machines. TÜV SÜD Industrie Service GmbH has now completed its first audit of a manufacturer of metal powder at Rosswag GmbH. The audit forms part of a new certification programme based on the AD 2000 Code for pressure equipment and thus, mutatis mutandis, the European Pressure Equipment Directive (PED).
Additive manufacturing (AM) presents metal powder manufacturers with new challenges. While a large array of different alloys is available for conventional manufacturing procedures, there is only a handful of standard alloys for the powder-bed process. On the other hand, demand is high for complex material and process solutions that extend the benefits of additive manufacturing to a variety of products. TÜV SÜD has now developed a new certification programme enabling metal-powder manufacturers to prove the quality of their processes.
Reliable assessment and certification of metal-powder manufacturers
The certification programme developed by TÜV SÜD maps the essential safety requirements specified in Annex I to the EU Pressure Equipment Directive 2014/68/EU in reference to the material manufacturer, in conjunction with the detailed requirements of the W 0 leaflet of the German AD 2000 Code. The objective of the AD 2000 Code is to specify the essential safety requirements according to the PED. The code includes the general principles for materials, joining methods, personnel and the necessary qualification tests. “In our certification programme for metal-powder manufacturers, we have complemented the requirements of the PED and the W 0 leaflet with our expertise and experience in materials and welding technologies”, says Gunther Kuhn, Head of Product Management in the Plant Safety business unit of TÜV SÜD Industrie Service GmbH. “The programme provides us with an excellent basis for the reliable assessment and certification of metal-powder manufacturers.” In addition to quality assurance and traceability, it also covers evidence of the production reliability of certain material groups and the fundamental suitability of the metal powder for additive manufacturing.
In a pilot audit carried out at Rosswag Engineering, the certification programme has already been implemented successfully in practice. Rosswag Engineering specialises in the manufacture of custom metal powders and additive manufacturing components produced in an integrated process chain according to highest quality requirements. Rosswag GmbH is an international leading supplier of rolled rings and open-die forged products with weights of up to 4.5 tonnes per piece. One of the company’s special features is its 7,000-tonne material warehouse which accommodates over 400 metallic materials for production. Founded in 2014, the Rosswag Engineering division expanded Rosswag’s product portfolio with the addition of engineering services and innovative manufacturing methods, such as 3D printing of metallic components on laser powder-bed fusion (LPBF) machines. ‘Metal 3D printing’ is the colloquial term for an additive manufacturing method for the production of metallic components offering optimised functionality.
End-to-end monitoring along the value chain
In 2017, in-house metal-powder manufacturing for the qualification of new materials was introduced to the company’s additive manufacturing department. “The purchase of our own atomising plant made by BluePower Casting Systems GmbH has enabled us to control the entire process chain and massively reduce the time needed for the qualification of new materials”, explains Gregor Graf, Head of Engineering at Rosswag GmbH. “After completing the qualification process, we now have comprehensive data sets comprising metal powder characteristics and PBF process parameters as well as mechanical and technological, chemical and metallographic material properties.” This enables the company to consider the typical characteristics of the future component in conjunction with the manufacturing process, a particularly relevant feature for especially complex application scenarios involving additive manufacturing components.
In the certification process, the experts from TÜV SÜD Industrie Service GmbH focused on the processes applied to the manufacturing, testing and qualification of the metal powder at Rosswag and assessed these processes in an extensive on-site audit. “The successful audit result confirms that we have full control of our processes and that our production of metal powders for use in additive manufacturing satisfies very high quality standards”, emphasises Graf. For Rosswag, third-party assessment and certification by TÜV SÜD Industrie Service is an important contribution to maintaining competitive edge in a market that will see high dynamic and strong growth over the coming years. Gunther Kuhn anticipates that following the successful audit, the certification process will be completed within two months.