High Resolution X-ray CT for Polymer Materials Science

To be able to predict mechanical properties of a structural component made of heterogeneous polymers the knowledge of the geometrical details of the different phases is necessary. The size distribution and volume fraction of pores play an important role for polymer foams and also for Carbon or Glass Fibre Reinforced Composites. The 3D method CT is a method to characterize the morphology non-destructively. Quantitative as well as qualitative evaluations can support the improvement of production processes and can be used as reference method for other techniques. The CT scans were performed on a Sub-μm-CT Device Nanotom 180 NF. The resolution was adjusted to the size of the specimen and the structures that had to be detected. For data evaluation different software tools were used. The commercial standard evaluation software Volume Graphics Studio MAX 2.1 was used mainly for visualization and determination of porosity in CFRP. The analysis of foams was performed using MAVI 1.3. Newly developed algorithms were incorporated into the in-house framework iAnalyse and were used to determine fibre orientation and length distribution. This poster presents in different examples that high resolution X-ray CT can be used to determine three dimensional morphological properties. Especially for polymeric material, where high resolution and data quality is necessary, CT in addition with custom-tailored software algorithms is a valuable combination. Qualitative results can be gained quite easily and fast to get an overview of the morphology of a composite material. With additional effort and in comparison with standard methods it is possible to make quantitative evaluations. Presented quantitative evaluations are for example the orientation of glass fibres, the determination of the void content in Carbon Fibre Reinforced Composites or the distribution of Cellulose particles in a PUR foam.