Ceramic matrix composite

About: Ceramic matrix composite is a research topic. Over the lifetime, 7807 publications have been published within this topic receiving 117020 citations.

Processing of Silicon Carbide‐Mullite‐Alumina Nanocomposites

Abstract: Nanocomposite materials in the form of nanometer-sized second-phase particles dispersed in a ceramic matrix have been shown to display enhanced mechanical properties. In spite of this potential, processing methodologies to produce these nanocomposites are not well established. In this paper, we describe a new method for processing SiC-mullite-Al2O3 nanocomposites by the reaction sintering of green compacts prepared by colloidal consolidation of a mixture of SiC and Al2O3 powders. In this method, the surface of the SiC particles was first oxidized to produce silicon oxide and to reduce the core of the SiC particles to nanometer size. Next, the surface silicon oxide was reacted with alumina to produce mullite. This process results in particles with two kinds of morphologies: nanometer-sized SiC particles that are distributed in the mullite phase and mullite whiskers in the SiC phase. Both particle types are immersed in an Al2O3 matrix.

Joining of CVD-SiC coated and uncoated fibre reinforced ceramic matrix composites with pre-sintered Ti3SiC2 MAX phase using Spark Plasma Sintering

Abstract: CVD-SiC coated and uncoated ceramic matrix composites (C f /SiC and SiC f /SiC) were joined to their counterparts with a pre-sintered Ti 3 SiC 2 foil using Spark Plasma Sintering. For the first time pre-sintered Ti 3 SiC 2 foil was used as a joining filler. The joining parameters were carefully selected to avoid the decomposition of Ti 3 SiC 2 and the reaction between the joining filler and the CVD-SiC coating, which would have deteriorated the oxidation protective function of the coating. Conformal behaviour of the Ti 3 SiC 2 foil during the diffusion joining and the infiltration of the joining filler into the surface cracks in the CVD β-SiC coating allowed the filler to be more integrated with the matrix material. While diffusion bonding occurred during joining of the coated composites, a combination of both solid-state reaction and diffusion bonding was observed for the uncoated C f /SiC composites. This produced the lower shear strength (19.1 MPa) when compared to the diffusion bonded CVD-SiC coated C f /SiC (31.1 MPa).

Composite material protected against oxidation by a self-healing matrix, and a method of manufacturing it

Abstract: A composite material protected by oxidation at intermediate temperatures not exceeding 850°C comprises fiber reinforcement densified by a matrix which includes at least one self-healing phase including a glass-precursor component such as B4C or an Si-B-C system, together with excess free carbon (C) at a mass percentage lying in the range 10% to 35%. The, or each, self-healing phase can be interposed between two ceramic matrix phases, e.g. of SiC. While the material is exposed to an oxidizing medium, oxidation of the free carbon promotes oxidation of the precursor and transformation thereof into a glass capable of plugging the cracks in the matrix by self-healing.

Fiber-reinforced ceramics

Abstract: The present invention provides fiber-reinforced ceramics containing at least one member of fibers and whiskers as distributed in a sintering ceramic matrix, which comprises the ceramic matrix being composed mainly of SiC, Si 3 N 4 and Si 6-z Al z O z N 8-2 , where 0 < z ≤ 4, the fibers and the whiskers being composed of at least one of SiC, Si 3 N 4 and Si 6-z Al z O z N B-z , where 0 < z ≤ 4, and a coating film of C, B or BN being provided on the surfaces of the fibers and the whiskers. The fiber-reinforced ceramics have a high fracture toughness, K 1c , and a high bending strength, particularly K 1c of at least 10 MN/m 3/2 and a bending strength of at least 50 kg/mm 2 .