Effect of specific surface fraction of interphase boundaries on mechanical properties of ceramic-metal composites, obtained by pressure infiltration
Paulina Chabera, Anna Boczkowska, Jerzy Zych, Artur Oziębło, Krzysztof J. Kurzydłowski
Quarterly No. 3, 2011 pages 202-207
DOI:
keywords: porous ceramics, cast aluminium alloy, composite, specific surface fraction of the interphase boundaries
abstract Ceramic-metal composites, obtained via pressure infiltration of porous ceramics Al2O3 by cast aluminium alloy EN AC-AlSi11 (AK11), were studied. As a result, composites of two interpenetrating phases are obtained. They are composed of 30 vol.% of ceramics. The pore sizes of the ceramic preforms varied from 150 to 500 μm. The results of the X-ray tomography proved very good infiltration of the pores by the metal. The residual porosity is approximately 9 vol. %. The obtained microstructure with percolation of the ceramic and metal phases gives the composites good mechanical properties together with the ability to absorb strain energy. Image analysis has been used to evaluate the specific surface fraction of the interphase boundaries (Sv). The presented results of the studies show the effect of the surface fraction of the interphase boundaries of ceramicmetals on the composite compressive strength, hardness and Young’s modulus. In addition, the mechanical properties depend on the degree of infiltration. Compression tests for the obtained composites were carried out, and Young’s modulus was measured by application of the DIC (Digital Image Correlation) method. Moreover, Brinell hardness tests were performed. The composites microstructure was studied using scanning electron microscopy (SEM). SEM investigations showed that the pores are almost fully filled by the aluminium alloy. The obtained results show that the infiltration method can be used to fabricate composites with percolation of the microstructure. However, the research is at its early stage and will be continued in the sphere of the characteristics of interphase boundaries.