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Fatigue behaviour of SiC |
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| Authors: | J HUANG J E SPOWART J W JONES |
| Affiliation: | Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA;, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio, USA |
| Abstract: | The fatigue behaviour of a 2009/SiC/15p‐T4 DRA composite has been examined in the very high cycle fatigue (VHCF) regime where 107≤Nf≤ 109 cycles. Ultrasonic fatigue was used to achieve the very high cycle counts. Careful processing yielded a composite with a very homogeneous particle distribution with minimal clustering. Fatigue crack initiation was observed almost exclusively at AlCuFe inclusions with no crack initiation observed at SiC particle clusters. Fatigue lives at a given stress level exhibited minimal scatter and subsurface crack initiation was observed in all cases. This behaviour is consistent with the presence of a low number density of critical inclusions that are responsible for crack initiation very early in fatigue life. |
| Keywords: | critical number density of inclusions discontinuously reinforced aluminium composite subsurface crack initiation ultrasonic fatigue very high cycle fatigue |