caa a22 4500 388018739 CHVBK 20180307124918.0 cr unu---uuuuu 161130e199806 xx s 000 0 eng 10.1557/JMR.1998.0213 doi S0884291400044496 pii (NATIONALLICENCE)cambridge-10.1557/JMR.1998.0213 Hi-Nicalon fiber-reinforced celsian matrix composites: Influence of interface modification [Elektronische Daten] Unidirectional celsian matrix composites having 42-45 vol% of uncoated or BN-SiC coated Hi-Nicalon fibers were tested in three-point bend at room temperature. The uncoated fiber-reinforced composites showed catastrophic failure with strength of 210 ± 35 MPa and a flat fracture surface. In contrast, composites reinforced with coated fibers exhibited graceful failure with extensive fiber pullout. Values of first matrix cracking stress and strain were 435 ± 35 MPa and 0.27 ± 0.01%, respectively, with ultimate strength as high as 960 MPa. The elastic Young modulus of the uncoated and coated fiber-reinforced composites were 184 ± 4 GPa and 165 ± 5 GPa, respectively. Fiber push-through tests and microscopic examination indicated no chemical reaction at the uncoated or coated fiber-matrix interface. The low strength of composite with uncoated fibers is due to degradation of the fiber strength from mechanical damage during processing. Because both the coated- and uncoated-fiber-reinforced composites exhibited weak interfaces, the beneficial effect of the BN-SiC dual layer is primarily the protection of fibers from mechanical damage during processing. Copyright © Materials Research Society 1998 Bansal Narottam P. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135-3191 Eldridge Jeffrey I. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135-3191 Journal of Materials Research Cambridge University Press 13/6(1998-06), 1530-1537 0884-2914 13:6<1530 1998 13 JMR https://doi.org/10.1557/JMR.1998.0213 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1557/JMR.1998.0213 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bansal Narottam P. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135-3191 NATIONALLICENCE 700 1- Eldridge Jeffrey I. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135-3191 NATIONALLICENCE 773 0- Journal of Materials Research Cambridge University Press 13/6(1998-06), 1530-1537 0884-2914 13:6<1530 1998 13 JMR CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge