ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract 2D-carbon-carbon/ceramic composites, made from a 2D-carbon-carbon (2D-C-C) porous preform infiltrated with BN, SiC, TiC or B4C, are mechanically characterized under compression loading in directions parallel or orthogonal to the carbon fabric layers. Three types of behaviour are observed: non-linear and time dependent behaviour, a quasi-linear domain and a “pseudo-plastic” behaviour related to damaging mechanisms. Underp-compression, the variations of the Young modulus as a function of compacity obey a parabolic or linear law depending on whether the material is weakly or highly densified. Undero-compression, an exponential law is observed whatever the densification degree. The variations of failure strength compacity follow similar laws. Phenomenological models are given which depict quite well the mechanical behaviours of the composites. Undero-compression, failure occurs as the result of damaging mechanisms taking place within the inter-layer ceramic bridges binding the fabric layers together. Underp-compression, a transition is observed, from interlayer delamination to intralayer failure, for a critical compacity of about 0.85 provided the infiltrated ceramic is strong enough (i.e. for SiC and TiC). Such a transition is assumed to also occur for 2D-C-C/B 4 − C composites. On the contrary, for weak ceramic matrices (e.g. BN), failure inp-compression always occurs by delamination. The results suggest that the composite toughness could be increased by an optimization of the composite microstructure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01161188
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