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.

A preservation study of carbon nanotubes in alumina-based nanocomposites via Raman spectroscopy and nuclear magnetic resonance

Abstract: Raman spectroscopy was used to study the preservation of the carbon nanotube structure in nanotube-reinforced alumina nanocomposites consolidated via spark plasma sintering (SPS). A series of Raman spectroscopy experiments was used to identify the thermal breakdown temperature of single-walled carbon nanotubes (SWCNTs) embedded in nanocrystalline alumina. It was found that the carbon nanotube structure remains intact after sintering at 1150 °C, but almost completely breaks down by 1350 °C after only 5 min. Also, 27Al nuclear magnetic resonance (NMR) was used to study the chemical and structural effects of high-energy ball milling (HEBM) and SPS consolidation on pure alumina and SWCNT-alumina nanocomposites. HEBM does not change the mixed coordination number of the as-received alumina, but slight peak shifts indicate residual stresses. No Al4C3 was detected in any of the consolidated samples – even up to 1550 °C for 10 min. Thus, it is concluded that consolidation of carbon nanotube-reinforced composites should be completed at temperatures below ∼1250 °C in order to preserve the carbon nanotube structure.

Structural and mechanical aspects of multilayer graphene addition in alumina matrix composites–validation of computer simulation model

Abstract: Since relationships between the structure and properties of ceramic-graphene composites are still not sufficiently defined, some numerical methods may facilitate the design of optimal material for new applications. In order to investigate such relationships, the methods for modelling the structure of composites with different sizes, shapes and spatial distributions of MLG (multilayer graphene) in the ceramic matrix have been developed. Using advanced methods of sintering SPS (Spark Plasma Sintering), two kinds of Al 2 O 3 matrix composites were prepared with the participation of multilayer graphene flakes up to 2 wt.%. (3.56 vol.%). Studies of the microstructure and the basic mechanical properties suggesting a very strong impact of graphene flakes within a range of small volume additions. Thus there is a clear deterioration of the properties of composites with volume shares exceeding 1%, which may be due to changes of the graphene nanoplatelets and agglomerates shape.

Surface modification of graphene oxide nanoplatelets and its influence on mechanical properties of alumina matrix composites

Abstract: This paper discusses the effect of modified graphene oxide nanoplatelets (RGO-Al 2 O 3 ) and unmodified graphene oxide nanoplatelets (GO) addition on the microstructure and mechanical properties of alumina matrix composites. The sinters were prepared by powder metallurgy processing using Spark Plasma Sintering to consolidate the powder mixtures. Moreover, the influence of applied reinforcing phase on the fracture mechanism was also investigated. Significant improvement of the fracture toughness (60%) for the composites with 0.5 wt.% RGO-Al 2 O 3 compared to the reference sample was observed. Moreover, 20% higher K IC was noticed for RGO-Al 2 O 3 reinforced composites than for Al 2 O 3 -GO.