Design-Opportunities and Limitations on Additive Manufacturing Determined by a Suitable Test-Specimen

The key-feature all additive manufacturing processes have in common is parts being built up in layers. Due to this tool-less build-up principle, the degree of freedom in design is huge compared to conventional manufacturing processes. For instance rear sections, inner cavities, conformal cooling-channels and lightweight-structures can be realized without a significant rise of manufacturing-costs. However there are some specific limitations coming along with the layer-wise build-up. Depending on layer-thickness and the orientation of a surface, the so-called stair-step effect occurs with different levels of intensity. Furthermore some additive manufacturing processes have to use support-structures. These structures are used to hold the part in place or to lead the pro-cess heat away from the melting-zone. In order to convey these limitations and to show how de-tailed and filigree parts can be generated, a test-specimen has been designed that suits processes withand without support-structures. The geometry of the specimen`s bottom side contains chamfers and notches, so the amount of necessary supports is kept as low as possible and the specimen can be separated from its build-platform without complications. Furthermore, the specimen is designed as a web of test-areas, connected by bars. This way the curling effect that often leads to aborts in additive manufacturing processes is prevented and thus cannot have an influence on the geometries tested on the speci-men. The presentation is about showing first test results of Laser Beam Melted, Laser Sintered and Fused Layer Modeled specimens that have been evaluated by sight test and measured by a coordinate measuring machine. In addition the content of the individual test-areas will be ex-plained.