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.

The Mechanical Performance of Fiber Reinforced Ceramic Matrix Composites

Abstract: This article evaluates the current understanding of relationships between microstructure and mechanical properties in ceramics reinforced with aligned fibers. Emphasis is placed on definition of the micromechanical properties of the interface that govern the composite toughness. Issues such as the debond and sliding resistance of the interface are discussed based on micromechanics calculations and experiments conducted on both model composites and actual composites.

Crack-healing behaviour of mullite/SiC/Y2O3 composites and its application to the structural integrity of machined components

Abstract: High-strength mullite/SiC/Y 2 O 3 composite ceramics with a great crack-healing ability were developed and subjected to three-point bending. A semicircular surface crack 100 μm in diameter was made in each specimen. Crack-healing behaviour was systematically studied as a function of crack-healing temperature and healing time, and the bending strength of the specimens crack-healed up to 1573 K was investigated. The effects of the crack-healing treatment on the structural integrity and reliability of machined components were studied systematically. Four main conclusions were drawn from the present study: (1) mullite/SiC/Y 2 O 3 composite ceramics have the ability to heal after cracking from 1423 K to 1673 K in air, (2) the heat-resistance limit temperature for strength of the crack-healed specimen is ≅1473 K, while at 68% of the specimens fractured from outside the crack-healed zone in the tested-temperature range of 300–1573 K, (3) due to the crack-healing treatment, the strength of the machined specimen increased by 40–200%. Local fracture strength was assumed to recover completely, and the cracks formed by machining were healed completely, and (4) a large self-crack-healing ability is desirable for obtaining a higher structural integrity in ceramic components.

Effect of Loading Rate on the Monotonic Tensile Behavior of a Continuous-Fiber-Reinforced Glass-Ceramic Matrix Composite

Abstract: The stress-strain behavior of a continuous-fiber-reinforced ceramic matrix composite has been measured over a wide range of loading rates (0.01 to 500 MPa/s). It was found that the loading rate has a strong effect on almost every feature of the stress-strain curve: the proportionality stress, the composite strength and failure strain increase with increasing loading rate. The microstructural damage varies also with the loading rate; with increasing loading rate, the average matrix crack spacing increases and the average fiber pullout length decreases. Using simple models, it is suggested that these phenomena are caused partly by time-dependent matrix cracking (due to stress corrosion) and partly by an increasing interfacial shear stress with loading rate.

The effects of multiwalled carbon nanotubes on the hot-pressed 3 mol% yttria stabilized zirconia ceramics

Abstract: The bulk composites of 3 mol% yttria stabilized zirconia ceramics reinforced by multiwalled carbon nanotubes were prepared by ball milling, spray-drying and hot-pressing processes. The effects of MWCNTs’ contents and heterocoagulation pretreatment on the mechanical properties of 3Y–ZrO 2 /MWCNTs’ composites were investigated at room temperature. Experimental results showed that the heterocoagulation pretreatment played a vital role in homogeneous dispersion of MWCNTs in the ceramic matrix. The flexural strength of 989.8 ± 20.0 MPa and fracture toughness of 5.77 ± 0.06 MPa M 1/2 were obtained for the composite with 1.0 wt.% of MWCNTs’ content, which were 135.3 MPa (or 8.4%) higher in flexural strength and 0.92 MPa M 1/2 (or 21.1%) higher in fracture toughness than those of blank 3Y–ZrO 2 , respectively. The mechanisms of strengthening and toughening of the composites could be attributed to the synergic effects of bridging, pulling out of MWCNTs and their promotive effects on the phase transformation of the ceramics.