Microstructure and mechanical behaviour of a Nextel (TM) 610/alumina weak matrix composite subjected to tensile and compressive loadings

摘要

The present study was aimed at determining the mechanical behaviour of a weak matrix oxide/oxide CMC subjected to tensile and compressive loadings in the fibre direction and at identifying the damage mechanisms. The material consisted of Nextel (TM) 610 fibres (8 HSW) embedded in an alumina matrix, with a 49 % fibre volume fraction and 24 2 % total porosity. The average ultimate tensile stress and strain of the material were, respectively, 260 +/- 37 MPa and 0.3 +/- 0.09 % under tensile loading and 261 +/- 69 MPa and 0.19 +/- 0.04 % under compressive loading. Three types of pores were differentiated within the material: nanopores (13 +/- 1 %), micropores (6 +/- 2 %) and macropores (5 +/- 1 %). The latter appear to be the most detrimental for the material, enhancing delamination. The damage mechanisms of the material were assessed through SEM examination and in situ tensile tests. (C) 2017 Elsevier Ltd. All rights reserved.