| |
System- and time-independent repeatability and non-destructive component inspection of SLS parts
Soeren and Dr. Volker Griessbach, VG Kunststofftechnik GmbH, Chemnitz, Germany
Dr. Ralf Lach, Polymer Service GmbH, Merseburg, Germany
Prof. Dr. Wolfgang Grellmann, Polymer Service GmbH, Merseburg Germany
ABSTRACT - Notwithstanding layer-based processing offer numerous new opportunities, the high risk of failure is still an unsolved problem. An everyday occurrence is that a first part has good mechanical response whereas a second part shows breakdown due to a weakness inside. The unpredictable flaws inside the parts, underlying failure, are almost caused by unsteady process parameters like non-constant temperature and laser power. Therefore, experiences of using the process have to exceedingly broaden now and in future. Particularly, this requires to ensure the repeatability on different machines at different times and to develop a non-destructive testing method for localizing weakness right on the final product.
V.G. Kunststofftechnik GmbH and Polymer Service GmbH analysed an improved SLS process for generating parts with isotropic mechanical properties, high detail precision and a system- and time-independent repeatability like in injection moulding.
For proving the level of quality a non-destructive test has been developed. Immersion of SLS or FDM parts by a coloured liquid for a certain time leads to diffusion into areas having low density. Laws inside the parts such as not sintered layers or degraded layers etc. become visible under vacuum. This new approach along with the well-known tensile test according to ISO ensures the best possible quality and provides confidence in using layer-based processing.
Biography
Dipl. Phys. Soeren Griessbach, born in Eastern Germany 1980, was joining the V.G. Kunststofftechnik GmbH, a RP service company of his father, at the age of 14. Starting with vacuum casting and handling a SLA 250 machine he got more and more into the business. After receiving his Diploma in Physics from the University of Technology Chemnitz, Germany, and working in sales and customer service for a year, he began to optimise the lasersintering process. In 2006 he got a position as an external postgraduate in Prof. Grellmann's group at the Martin-Luther University Halle-Wittenberg.
< back
|
|
