Polarization Light Optical Texture Analysis for the Structural Characterization of CIM Components

Abstract:

The mechanical properties of ceramic injection molded (CIM) components are largely influenced by microstructural inhomogeneities that result from the interaction of rheological properties of the thermoplastic feedstock with machine parameters and the design of mold and injection gate. These inhomogeneities (e. g. texture, turbulences, joints, and density gradients) can form weak spots in the material or lead to anisotropy of the material properties. Additionally, they can influence the local sinter shrinkage behavior and thereby lead to the formation of residual stresses in the component. For this reason, it is of great importance to analyze these inhomogeneities in order to improve CIM processes and CIM components. A method has been developed for the investigation of preferred crystal orientation and microstructural defects, applying polarization microscopy of ceramic thin sections and colorimetry. Polarization microscopy is used in order to visualize the crystal orientation of the single grains. Different orientations of the optical axes will result in different colors of interference for optically uniaxial materials. The polarization micrographs themselves are already suitable for the analysis of the microstructure of CIM components regarding texture, separation planes, etc. Colorimetry is used in order to measure and describe the colors in a standardized color system. By means of color/orientation calibration curves that are measured with single crystal references, a quantitative description of the orientation of single grains as well as texturized areas can be obtained.

• Periodical: Advances in Science and Technology (Volume 45)
• Pages: 1690-1695
• DOI: https://doi.org/10.4028/www.scientific.net/AST.45.1690
• Online since: October 2006
• Authors: Johannes Rauch, Frank Kern, Rainer Gadow
• Keywords: Ceramic Injection Molding (CIM), PLOTA, Polarized Light Microscopy, Texture Analysis

References

[1] R. Gadow and G. Süssmuth: Spritzgießen in der technischen Keramik, pp.206-210 (Vulkan Verlag, Essen 1988).

[2] Arburg: Pulverspritzgießen: Herstellung komplexer Formteile aus Metall und Keramik, Technische Information, p.20 (1992).

[3] M.J. Edirisinghe and J.R.G. Evans: Fabrication of Engineering Ceramics by Injection Moulding Part II: Techniques (Int. J. High Technology Ceram. 2 (1986) pp.249-278.

DOI: 10.1016/0267-3762(86)90020-2

[4] G.H. Eisbacher: Einführung in die Tektonik (Ferdinand Enke Verlag, Stuttgart 1991).

[5] R. Fischer: Charakterisierung herstellungsbedingter Texturen in spritzgegossenen Al2O3- Keramikbauteilen, (Diplomarbeit, Institut für Mineralogie und Kristallchemie, Universität Stuttgart 1991).

[6] V. Randele and O. Engler: Introduction to Texture Analysis (Gordon and Breach Science Publischers, The Netherlands 2000).

[7] G. Wessermann and J. Grewen: Texturen metallischer Werkstoffe (Springer Verlag Berlin 1939).

[8] DIN 6174: Farbmetrische Bestimmung von Farbabständen nach der CIELABFormel (1979).

DOI: 10.31030/2871227

[9] H. Kipphan: Handbuch der Printmedien (Springer Verlag, Berlin, Heidelberg, New York 2000).

[10] G.M. Sarantschina: Die Fedorow- Methode (VEB Deutscher Verlag der Wissenschaften, Berlin 1963).

[11] J.J. Marchesi: Lehrbuch der Digitalfotografie (Loseblattsammlung, Verlag Photographie, Gilching 2000).

[12] R. Fischer: Optimierung des Fertigungsprozesses von keramischen Spritzgießbauteilen durch lichtoptische Texturanalyseverfahren (Ph.D. Thesis, Faculty of mechanical Engineering, University of Stuttgart 2004).