APPLICATION OF DIFFERENT NON-DESTRUCTIVE METHODS FOR POROSITY DESCRIPTION IN CERAMIC-METAL COMPOSITE FIBRES REINFORCED CASTS
Katarzyna Gawdzińska1, Zbigniew Pędzich
Quarterly No. 4, 2010 pages 333-339
DOI:
keywords: composites, porosity, non-destructive methods
abstract The paper describes the application of non-destructive methods, X-ray defectoscopy, ultrasonic defectoscopy and computer tomography, for porosity analysis in ceramic-metal composite fibres reinforced casts. As a sample the composite made of AlSi11 matrix and carbon fibers reinforcement was applied. The paper presents the investigative possibilities of mentioned methods and samples of performed analyses. Composites used in investigations differed in density and flaws distribution according to different applied manufacturing conditions (saturation pressure). X-ray defectoscopy allows determining pores in products about 10 mm in size. The flaw size which can be distinguish is no smaller than 0.3 mm. Detail differences between sample sectors could be described as differences in X-ray images optical density. The method allows to distinguish pores in the milimeters range. Ultrasonic defectoscopy gives a possibility of fast nontestructive analyze of density fluctuation in the bulk sample by registration of wave volocity and attenuation coefficient of measured sample changes. However, determination of the flaw type and its precise location is rather difficult. Nowadays, computer tomography give the best potential possibilities of composite structure determination. The detailed specimen description could be done in both, 2D and 3D spaces. The method gives the possibility of observation of any optional cross-section in the sample. It is worth noticing that the detail description of the pores shape could give the information about their origin. The wide application of computer tomography is strongly limited by high cost of analyze.