摘要:
Sintered bodies with the primary phase of .beta. and/or .alpha. prime sialon. In the sialon phase which is the primary phase, hafnium oxide and silicon carbide are dispersedly contained as dispersion phases. 1 to 60 parts by weight of hafnium oxide are contained in 100 parts by weight of the primary phase. 5 to 30 parts by weight of silicon carbide are contained in 100 parts by weight of the primary phase. Hafnium oxide suppresses decrease of sintering characteristic which is caused by silicon carbide. Thus, a large amount of silicon carbide can be added, thereby improving the fracture toughness value.
摘要:
According to a ceramic fiber reinforced ceramic matrix composite material of the present invention, a ceramic fiber reinforced ceramic matrix composite material 1 comprises a composite ceramic matrix, and a preform 5 resulting from a fiber bundle 3 obtained by bundling a plurality of ceramic fibers 2 and disposed therein, and is characterized in that a first ceramic matrix M1 is formed in an inner space of the fiber bundle 3 and at a region adjacent to an outer periphery thereof, and a second ceramic matrix M2 is formed in an inner space of the preform 5 and at an outer peripheral region thereof, the space and region of the preform being defined except for those of the fiber bundle. Also characteristically, ceramic fibers are compositely disposed in a fiber volume fraction (Vf) of greater than 10% in a reaction-sintered ceramic matrix. It is further preferred that the composite material be provided on a surface thereof with a coat layer composed solely of a ceramics and having a thickness of not less than 50 &mgr;m.
摘要:
A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.