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.

Method for producing a thermal stress-resistant, rotary regenerator type ceramic heat exchanger

Abstract: A thermal stress-resistant rotary regenerator type ceramic heat exchanger comprising a plurality of ceramic honeycomb structural matrix segments bonded by a ceramic binder is produced by extruding a plurality of ceramic honeycomb structural matrix segments, firing the segments, bonding the segments with one another by application of a ceramic binder, said ceramic binder after the subsequent sintering having substantially the same mineral composition as said ceramic matrix segments and the thickness of 0.1 to 6 mm, and a difference in thermal expansion being not greater than 0.1% at 800° C. relative to the ceramic matrix segments, drying the bonded segments, and firing the dried bonded segments.

Bond enhancement for thermally insulated ceramic matrix composite materials

Abstract: A composite structure ( 62 ) having a bond enhancement member ( 76 ) extending across a bond joint ( 86 ) between a ceramic matrix composite (CMC) material ( 80 ) and a ceramic insulation material ( 82 ), and a method of fabricating such a structure. The bond enhancement member may extend completely through the CMC material to be partially embedded in a core material ( 84 ) bonded to the CMC material on an opposed side from the insulation material. A mold ( 26 ) formed of a fugitive material having particles ( 18 ) of a bond enhancement material may be used to form the CMC material. A two-piece mold ( 38, 46 ) may be used to drive a bond enhancement member partially into the CMC material. A compressible material ( 56 ) containing the bond enhancement member may be compressed between a hard tool ( 60 ) and the CMC material to drive a bond enhancement member partially into the CMC material. A surface ( 98 ) of a ceramic insulation material ( 92 ) having a bond enhancement member ( 96 ) extending therefrom may be used as a mold for laying up a CMC material.

Modeling the Tensile Behavior of Cross-Ply C/SiC Ceramic-Matrix Composites

Abstract: The tensile behavior of cross-ply C/SiC ceramic-matrix composites (CMCs) at room temperature has been investigated. Under tensile loading, the damage evolution process was observed with an optical microscope. A micromechanical approach was developed to predict the tensile stress–strain curve, which considers the damage mechanisms of transverse multicracking, matrix multicracking, fiber/matrix interface debonding, and fiber fracture. The shear-lag model was used to describe the microstress field of the damaged composite. By combining the shear-lag model with different damage models, the tensile stress–strain curve of cross-ply CMCs corresponding to each damage stage was modeled. The predicted tensile stress–strain curves of cross-ply C/SiC composites agreed with experimental data.

Synergistic reinforcement of carbon nanotubes and silicon carbide for toughening tantalum carbide based ultrahigh temperature ceramic

Abstract: Tantalum carbide (TaC) is an ultrahigh temperature ceramic, where low damage tolerance limits its potential application in propulsion sector. In this respect, current work focuses on enhancing the toughness of TaC based composites via synergistic reinforcement of SiC and carbon nanotubes (CNTs). Spark plasma sintering of TaC, reinforced with 15 vol% SiC and 15 vol% CNT (processed at 1850 °C, 40 MPa, 5 min), has shown enhanced densification from ∼93% (for TaC) to ∼98%. Potential damage of the tubular CNTs to flaky graphite was revealed using transmission electron microscopy, and was supplemented via Raman spectroscopy. SiC addition has enhanced the hardness to ∼19.5 GPa while a decreases to 12.6 GPa was observed with CNT addition when compared to the hardness of TaC (∼15.5 GPa). The increase in the indentation fracture toughness (from 3.1 MPa m1/2 for TaC to 11.4 MPa m1/2) and fracture strength (from ∼23 MPa for TaC to ∼183 MPa) via synergetic reinforcement of SiC and CNT is mainly attributed to energy dissipating mechanisms such as crack branching, CNT bridging, and crack-deflection. In addition, the reduction of interfacial residual tensile-stresses with SiC- and CNT-reinforcement, resulting an overall increase in the fracture energy and toughening, is also established.