Title: Mechanical properties of aluminium oxide at high loading rates

Authors: Zdenek Bilek, Jan Helesic, Jaroslav Buchar

Addresses: Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, Zizkova 22, 616 62 Brno, Czechoslovakia. ' Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, Zizkova 22, 616 62 Brno, Czechoslovakia. ' Agricultural University, Department of Physics, ZemZdelskA 2, 613 00 Brno, Czechoslovakia

Abstract: The accurate evaluation of dynamic mechanical and fracture properties of structural ceramics has become increasingly important for fracture safe design of structural components subjected to impact loadings. The results of compression tests of A1₂0₃, A1₂0₃+TiC and A1₂0₃+ZrO₂ at high strain rates and room temperature are presented. The dynamic loads applied to the penny shaped specimens of various thicknesses were produced and measured accurately by the computer operated Hopkinson Split Pressure Bar technique (HSPB). The results indicate the possibility of shock wave formation due to the nonlinear response of the porous body during compaction due to porosity reduction and increase of elastic constants. The influence of stress pulse shape and duration is discussed. Modifying the Grady|s theory a simple criterion for fragmentation has been proposed.

Keywords: alumina ceramic systems; dynamic loading; fragmentation; fracture toughness; impact diametral compression test; porosity; mechanical properties; aluminium oxide; structural ceramics; strain; shock wave formation; stress pulse.

DOI: 10.1504/IJMPT.1993.036549

International Journal of Materials and Product Technology, 1993 Vol.8 No.2/3/4, pp.381 - 394

Published online: 04 Nov 2010 *

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