Material- and process-oriented non-destructive testing of additively manufactured components by computed tomography
The aim of the project is to characterize the pore morphology and microstructure of components made of AlSi10Mg produced by LPBF and to investigate the influence of component geometries and process settings on these properties. A special focus lies on the investigation of samples by means of µCT, which allows to establish correlations between the position and morphology of pores in the component with the associated laser path, for which purpose own data analysis software is developed. The obtained data can be used to characterize local mechanical properties of the additively manufactured components and thus improve printing strategies. Furthermore, process-related component weaknesses can be predicted. In-situ tensile tests in µCT, which allow deformations to be recorded three-dimensionally, allow a precise observation of damage development starting from process-related pores in the elasto-plastic range.
Motivation
In recent years, the powder bed based additive manufacturing of components has been continuously developed with regard to its use in new fields of application. To ensure consistent mechanical properties of the components in order to guarantee precise design and safe operation remains a challenge. These properties are determined by process-related defects, the distribution of which in the printed components depends not only on the process control but also on the component geometry and its local characteristics. The pore morphology and distribution as well as the microstructure of AlSi10Mg components manufactured by LPBF will be characterized, especially with regard to correlations with the component geometry and process settings, in order to finally develop improved manufacturing strategies.
Goals
- Improvement of the process control with regard to the reduction and formation of porosity
- Development of automated, materialographic evaluation methods based on micro-computer tomographic data for microstructural features in SLM
Investigations
- Porosity with variation of process and component parameters
- Correlation of microstructural properties with the laser path
- Development of image processing methods for the visualization of microstructure characteristics
- µCT in-situ tests on near-component specimens
