Interlaminar shear fatigue of a two-dimensional carbon fibre reinforced silicon carbide composite

Liu

et al. 2016

A new surface micromachining way of ultrashort plus laser for C/SiC composites with high quality and efficiency was demonstrated, including picosecond and femtosecond laser. Surface morphologies, element content and bonding states of C/SiC composites were analysed in detail after machined by picosecond and femtosecond laser power respectively. For femtosecond laser machining, the amount of nanoparticles increased with increasing laser power. At 20 and 50 mW, Si-C, C-C and Si-O bonds existed in nanoparticles, while Si-C bonds disappeared at 70 mW. For picosecond laser machining, cauliflower-like particles and periodic ripple with certain depth were formed distinctly. Furthermore, thermal ablation phenomenon occurred, and only Si-O bonds existed in particles due to the oxidation of the carbon fibres and SiC matrix. The results showed that femtosecond laser with low power was more suitable to the surface machining due to better machining quality and less machining damage compared with high power picosecond laser.

Section: Resultsmentioning

confidence: 99%

Character and mechanism of surface micromachining for C/SiC composites by ultrashort plus laser

Liu

et al. 2016

“…[26][27][28][29][30][31] Meanwhile, carbon fibres have demonstrated their feasibility mainly as structural materials in aerospace and College of Materials Science and Engineering, Xi'an University of Science and Technology, No. 58 Yanta Middle Road, Xi'an, Shaanxi 710054, People's Republic of China aeronautic industries, [32][33][34][35][36] and they are very good reinforcements in improving thermal shock resistance of ceramics. 37 For examples, carbon fibre-reinforced Al 2 O 3 and ZrO 2 composites 38 presented good high-temperature strength, high toughness and thermal shock resistance.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, carbon fibres are the only structural materials, whose strength would not reduce, especially in the high-temperature inert environment above 2000°C. 26-31 Meanwhile, carbon fibres have demonstrated their feasibility mainly as structural materials in aerospace and aeronautic industries, 3236 and they are very good reinforcements in improving thermal shock resistance of ceramics. 37 For examples, carbon fibre-reinforced Al 2 O 3 and ZrO 2 composites 38 presented good high-temperature strength, high toughness and thermal shock resistance.…”

Section: Introductionmentioning

confidence: 99%

Effect of short carbon fibre concentration on microstructure and mechanical properties of TiCN-based cermets

Sun

Zhang

et al. 2016

Short carbon fibre (C f ) reinforced TiCN-based cermets (C f /TiCN composites) were produced by powder metallurgy method with pressureless sintering technology. The phase evolution, microstructure and fracture morphology of C f /TiCN composites were investigated. The results showed that TiC, TiN, WC, Cr 3 C 2 and Mo phases disappeared gradually and diffused into core and rim phases by dissolution-reprecipitation process, finally formed new hard TiCN core phases and complex compound (Cr, W, Mo, Ti)(CN) rim phases, with the sintering temperature increasing. The added C f did not change the 'core-rim' microstructure but improved the mechanical properties of TiCN-based cermets. The C f /TiCN composite containing 3 wt-% C f achieved the best comprehensive mechanical properties, with fracture toughness and bending strength increasing by about 14.4% and 30.8%, respectively, when compared with the composite without C f . Toughening and strengthening mechanisms of C f /TiCN composite were concluded as crack deflection and branch, as well as the pull-out, fracture and bridging of carbon fibres.

“…C F CCs are quite advantageous because they are lightweight structural materials that exhibit a much higher resistance to high temperatures and aggressive environments than metals, superalloys and other conventional engineering materials. [1][2][3][4][5][6] For continuous carbon fibre reinforced Si 3 N 4 (C F /Si 3 N 4 ) composites, a large amount of fracture energy is consumed during the process of fracture via crack deflection, fracture and pull-out of C F , and thus, the strength and toughness of the composites are eventually improved, sustaining the intrinsic high-temperature performance of the Si 3 N 4 ceramic.…”

Section: Introductionmentioning

confidence: 99%

Influence of sintering process on microstructure and fracture behavior of C_F/Si₃N₄laminated ceramic composites

Sun

Zhang

Tian

et al. 2016

Carbon fibre reinforced Si 3 N 4 (C F /Si 3 N 4 ) biomimetic laminated ceramic composites were prepared through rolling, alternate stacking of two-dimensional carbon fibre cloth and Si 3 N 4 green layers, burning out of organic components and hot-press sintering. The effects of the sintering process and sintering additives on the microstructure, fracture behavior and toughening mechanism of the composite were analysed. When sintered at 18508C for 1.5 h with Al 2 O 3 , Y 2 O 3 and MgO as sintering additives, a fully densified composite was obtained with homogeneous and moderate bonding interfaces between C F and the Si 3 N 4 matrix, presenting improved flexural strength of 374.93 MPa and fracture toughness of 10.71 MPa m 1/2 , which were increased by 13.20% and 71.36% respectively, as compared with the monolithic Si 3 N 4 ceramic. The primary toughening mechanism of the composite can be concluded as multiple crack deflection at the carbon fibre layers, fracture and pull-out of C F bundles and single C F within the carbon fibre layers.