Low temperature deposition of nanocrystalline silicon carbide films by plasma enhanced chemical vapor deposition and their structural and optical characterization J. Appl. Phys. 94, 5252 (2003); 10.1063/1.1609631 Hydrogen content and density in nanocrystalline carbon films of a predominant diamond character J. Appl. Phys. 94, 4589 (2003); 10.1063/1.1603951Modeling and analysis of hydrogen-methane plasma in electron cyclotron resonance chemical vapor deposition of diamond-like carbon Evaluation of the ion bombardment energy for growing diamondlike carbon films in an electron cyclotron resonance plasma enhanced chemical vapor deposition
The ® bre± matrix reaction that occurs during the processing of a Nicalon SiC ® bre± Pyrex glass matrix composite is analysed. Interphases are characterized by means of various complementary techniques: electron di raction, HRTEM, EDX, EELS, SIMS and XPS. Neither the results of the present study nor those previously obtained for Nicalon SiC ® bre± LAS (Li 2 O± Al 2 O 3 ± SiO 2) glass or LAS + MAS (MgO± Al 2 O 3 ± SiO 2 ) glass± ceramic matrix composites support the available model of reaction. An alternative reaction mechanism is suggested whereby the dissolved and non-bridging oxygen atoms of the matrix di use and oxidize SiC and SiO x C y in the ® bre. The reaction yields carbon and silicon oxycarbide in the ® bre and SiO 2 which dissolves into the matrix. When the oxygen in excess in the matrix is consumed, the reaction stops and the phases undergo a reorganization in the reaction layer which generates two interphases, one carbon rich and the other silicon oxycarbide rich. These interphases are observed at the ® bre periphery in all glass or glass± ceramic matrix composites. § 1. Introduction Glass or glass± ceramic matrix composites are developed for thermostructural applications such as in aircraft parts submitted to severe thermomechanical stresses. Glass± ceramic is reinforced by means of long ® bres that are essentially stronger and less brittle than the matrix. This reinforcement yields composites with high strength and a`pseudoplastic' strain su cient to alleviate the catastrophic rupture mode of a brittle material. Amongst commercial ® bres, the SiC Nicalon 202 ® bre has been successfully used in the last years. The mechanical properties of Nicalon± glass matrix composites depend on the nature of the interphases that develop during material processing (Brennan 1988, Lancin 1991. A good characterization of the reaction between the ® bre and the matrix together with the understanding of this reaction are essential in order to elaborate composites with required speci® cations.Studies of the interphases produced in the course of the ® bre± matrix reaction have been conducted in a number of composites based on various matrices (Brennan 1988, Chen et al. 1989, Bonney and Cooper 1990. The most currently used are Li 2 O-Al 2 O 3 -SiO 2 (LAS) or CaO± Al 2 O 3 -SiO 2 (CAS) containing some additives such as niobium, arsenic or yttrium. In order to explain the formation of interphases, one usually refers to the model proposed by Cooper and Chyung (1987) which
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.