SIC BASED CERAMIC MATRIX COMPOSITES WITH LAYERED MATRICES AND METHODS FOR PRODUCING SIC BASED CERAMIC MATRIX COMPOSITES WITH LAYERED MATRICES

摘要

Ceramic matrix composites include a fiber network and a matrix including layers of first and second materials. The first material may include SiC. The second material may include an element that when oxidized forms a silicate that is stable at high temperatures, and can be Si3N4 or SiCN. The interface layer can be BN or pyrolytic carbon. The element that when oxidized forms a silicate that is stable at high temperatures is selected from the group consisting of yttrium, ytterbium, dysprosium, erbium, gadolinium, scandium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, terbium, holmium, thulium, lutetium, zirconium, niobium, molybdenum, hafnium, tantalum, rhenium, tin, selenium and tellurium. The matrix layers are deposited by chemical vapor infiltration. The CMC can also be a ceramic matrix composite, including: a plurality of fibers; individual first matrix layers surrounding each fiber; and individual second matrix layers surrounding each of the individual first matrix layers, the individual second matrix layers including an element that when oxidized forms a silicate that is stable at high temperatures. Or alternatively, a ceramic matrix composite, including: a first fiber; a first matrix layer surrounding the first fiber; a second matrix layer surrounding the first matrix layer, the second matrix layer including an element that when oxidized forms a silicate that is stable at high temperatures; a second fiber; a third matrix layer surrounding the second fiber; a fourth matrix layer surrounding the third matrix layer, the fourth matrix layer including an element that when oxidized forms a silicate that is stable at high temperatures; and a fifth matrix layer surrounding the second matrix layer and the fourth matrix layer. The CMC can also be a ceramic matrix composite, including: a network of fibers; a first matrix layer, the first matrix layer including silica; and a second matrix layer, the second matrix layer including a silicate.