Voxeljet - Q&A Few limitations in creating complex 3D-printed sand cores
Germany – The presentation of the results by voxeljet´s Director Casting Applications, Tom Mueller, took the first place in the category Best Paper Award on GIFA, a trade fair for the foundry sector. In his studies, he focused on 3D printed sand cores with complex geometries and their behaviour during casting.
It has been 15 years since printed sand moulds and cores viable for a wide range of alloys came onto the scene. Since then, the value of using printed sand moulds and cores in product development and in low volume manufacturing has been demonstrated many times over. As a result, most sand foundries have had some experience with printed cores and moulds and have used them to create prototype castings. While the use of printed cores with thicker sections has proven viable and is in common use, there was little known about the casting performance of long, thin printed cores. It was uncertain whether they would be strong enough to withstand the forces exerted by the flow of metal during filling. It was also uncertain whether they could adequately vent gases generated during the casting process. The paper presents the results of tests in which 36 cored castings were created using printed sand cores. Castings were examined to evidence of deflection and inadequate venting. Tom Mueller gives a brief overview of the current state of research and new applications.
ETMM: Tom, what was the major motivation for your research?
Mueller: The casting performance of larger printed furan cores has been demonstrated and documented. However, there are needs in industry for much smaller cores and little was known about how well they would perform. In particular, it was not known whether they would adequately vent gases generated in the casting process or whether they would be strong enough to withstand the stress encountered in filling. This investigation was done to answer those questions.
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