As the global technology and quality leader for high-end Additive Manufacturing (AM) solutions, EOS has, as one of its central concerns, the establishment of a holistic approach to quality assurance in series production. The AM process, which was mainly used for Rapid Prototyping in the early years, is increasingly making fully-fledged series production possible in many areas. Customers across a wide range of different industries are developing completely new applications, in medical and aerospace, for example.
Dr. Tobias Abeln, Chief Technical Officer (CTO) says, “Consistent and repeatable part quality is essential for series production applications. With its quality assurance concept, which is unique to the industry, EOS covers the three technological elements of Additive Manufacturing which have a direct influence on the quality of an additively manufactured component – namely, system, material and process. Thanks to the joint development and mutual adjustment of our systems, materials and processes, EOS has established conditions for the best possible part properties.”
Focus on technology development and quality assurance
EOS puts a high emphasis on technology development and quality assurance. At the headquarters in Krailling alone, there is an area of around 2,300 m² reserved for the seventy Additive Manufacturing systems used for research and development, quality assurance, application and training for both polymer and metal products. At the EOS Oy plant in Finland, an additional fifteen systems are being used for the development, qualification and quality assurance of metal materials. An additional twenty systems are available in the international EOS technology centres in the US, Singapore and China.
System: reliably meeting manufacturing standards
EOS GmbH has been certified to ISO 9001:2008 for the development and manufacturing, sales and service of systems and solutions for Additive Manufacturing using laser sintering technology since 1998. The Additive Manufacturing system on which products are manufactured is one of the most important pillars for reproducible and high product quality. Numerous quality assurance measures are in place to guarantee the reliable observance of manufacturing standards during the production of EOS metal systems. These are tested and validated within the context of the EOS machine acceptance test, during which defined reference parts are manufactured and then examined for numerous decisive criteria such as mechanical properties, tensile strength, elongation at break, surface quality and component density. Current DIN and ISO standards are applied for these tests. It goes without saying that a comprehensive check of all system components is done during the machine acceptance test.
Material: guaranteed consistent quality of every material batch
The materials used also have a major influence on the quality of the manufactured component. With the aid of multi-dimensional quality management, EOS guarantees reliable consistent quality for every material batch. The EOS Oy branch in Turku/Finland, which deals with the development, qualification and quality assurance of metal materials, has been certified to ISO 9001:2008 since 2013 and to the Medical Products Law ISO 13485:2003 since 2012.
Various test methods are used for the quality assurance of materials, starting with the delivery of the base powder. Every batch is examined for its correct chemical characteristics. With a view to Additive Manufacturing, the consistent grain size distribution is also checked. A second quality check takes place on the basis of a reference build job, where density cubes and tensile bars are manufactured according to fixed criteria under standardised conditions and then analysed. Further processing and packing only takes place once a batch has passed both test levels.
The corresponding mill test certificate is included with each delivery and details the test results. This provides customers with comprehensive documentation for their own internal quality management system.
Process: checked and validated parameters
The actual additive build process is the third decisive pillar of the EOS concept in the sense of guaranteeing standard manufacturing quality. This is concerned with the quality assured development of parameters sets used in the AM build process. At EOS, all the process parameters which are necessary for achieving certain component characteristics, such as laser power and layer thickness, are based on more than 20 years of experience and comprehensive series’ of tests. The required product characteristics can be achieved through the respectively optimum combination of individual parameters. A corresponding material data sheet provides a detailed description of the material characteristics which can be achieved on this basis.
For more information, visit: www.eos.info