Objetivo - To develop film-based radiographic, tomographic and holographic methods for quantitative nondestructive evaluation of high strength ceramics;- To combine X-ray and optical techniques to obtain information about correlation among the structural integrity of ceramic samples and the distribution of deformations during load tests;- To develop digital image processing software to maximise the amount of information that can be extracted from X-ray and holographic recordings.Expected Outcome- Quantitative interpretation of film-based X-ray radiographic and tomographic recordings and of holographic recordings is complicated. The results of the project are expected to contribute to the knowledge and application of the fundamental science of measurements and image science;- Quantitative nondestructive evaluation methods will provide researchers involved in the development of ceramic and composite materials with a useful tool to characterise the material during successive stages of production. This will make it possible to optimise materials and process parameters;- A new apparatus, based on the experimental set-ups of the project, may be of interest to producers of X-ray and/or holographic equipment. ResultsX-ray radiography - X-ray radiographic results were compared with the results obtained by surface analysis, 4-point bending tests, optical microscopy, scanning electron microscopy and density measurements on samples of high strength engineering alumina and alumina zirconia ceramics. A strong correlation was found between these results, implying that X-ray radiography may be used in combination with i.e. surface flaw analysis for nondestructive assessment of the sample strength.- Another major conclusion is that X-ray radiographic NDT is a useful tool for quality assurance even at the very early stage of the manufacturing process.X-ray tomography - A film-based tomographic system was developed. Film and object rotate synchronously around parallel axes carefully aligned in a vertical plane through the X-ray source, which was a micro-focus with focal spot size about 10 um. The resolution which could be obtained was not better than 50 um. The contrast resolution was limited to about 2%. Evidently, the spatial resolution sets a lower limit for achievable contrast resolution. Therefore, taking into account also the speed of investigation, especially the very time consuming alignment procedures, film-based X-ray tomography is rather to be considered as a specialised research method than a method suitable for industrial ceramic quality and process control.Holographic interferometry - Bars of ceramic samples were loaded in a three-line loading system with 50 mm separation among lines of contact and holographic interferograms were recorded. The results indicated that hidden defects could be detected by using holographic interferometric evaluation of the strain distribution under nondestructive load. Moreover, the location and the size of the defect could be estimated fairly well.Follow-up- Industrial CT-scanner : toward the end of the project a real-time X-ray system was installed. The system consists of a micro-focus tube (160 kVp, focal spot size ~ 10 um), an X-ray image intensifier tube, a CCD video camera and a frame grabber for digitising the video signal. Based on this system, a computer-assisted X-ray tomograph (a CT-scanner) for industrial use has been developed. In order to achieve this, a computer-controlled step-wise rotating object table has been constructed and a Windows program for data collection and tomographic reconstruction on a PC have been developed.- Important material and process parameters will be varied in the production of samples in order to optimise the properties of the resulting ceramic samples;- The samples will be tested by 4-points bending. X-ray radiography will be performed on all samples and few will be subject to more extensive study by tomographic methods;- Holographic interferometry with the double exposure technique will be applied to select ceramic plates. Anomalies in the resulting deformation or stress pattern will be related to defects revealed by the X-ray investigations. Programa(s) IC-ISC C - Activity (Euratom, EEC) on cooperation in science and technology, 1984- Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación CSC - Cost-sharing contracts Coordinador Danmarks Tekniske Universitet Aportación de la UE Sin datos Dirección 2800 Lyngby Dinamarca Ver en el mapa Coste total Sin datos Participantes (1) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo Danmarks Tekniske Universitet Dinamarca Aportación de la UE Sin datos Dirección 2800 Lyngby Ver en el mapa Coste total Sin datos
