Entity

Time filter

Source Type


Chen X.,Beihang University | Li S.,Beihang University | Chen Z.,Avic xiAn Aviation Brake Technology Co.
Materials at High Temperatures | Year: 2011

Joining of carbon fibre reinforced C- SiC dual matrix composite has been realized through a reaction joining process using boron-modified phenolic resin with B4C and SiO2 additives. The effect of the technological parameters on the strength of joints was investigated. The optimized technological parameters are the curing temperature of 200°C, the curing time of 2 hours and the curing pressure of 30 kPa, under which conditions, the obtained strength of the joint is equal to 82.6% of that of the substrate. The interlayer composed of Si, C, B and O is basically uniform and dense. There are no obvious cracks nor pores at the interfaces. The elements migrate across the interfaces, contributing to the enhancement of the joint strength. The results of heat treatment at 1500°C show good heat resistance of the joints. The B4C and SiO2 additives contribute to the densification of the interlayer and the adhesion at the interfaces. © 2011 Science Reviews 2000 Ltd. Source


Chen X.,Beihang University | Li S.,Beihang University | Chen Z.,Avic xiAn Aviation Brake Technology Co. | Wen N.,Beihang University
Journal of Materials Science | Year: 2011

Joining of carbon fiber reinforced C-SiC dual matrix composite (denoted by C/C-SiC) is critical for its aeronautical and astronautical applications. Joining of C/C-SiC has been realized through a reaction joining process using boron-modified phenolic resin with micro-size B4C and nano-size SiO2 powder additives. The effect of the heat-treatment temperature on the retained strength of the joints, calculated by dividing the strength of the heat-treated joints by the strength of the joints before heat-treatment, was studied. The maximum retained strength of the joints is as high as 96.0% after the heat-treatment at 1200 °C for 30 min in vacuum, indicating good heat resistance of the joints. The thickness of the interlayer of the joint after the heat-treatment is about 18 μm and it is uniform and densified. There are no obvious cracks or pores at the interfaces. During the heat-treatment, carbon, oxygen, silicon, and boron diffuse at the interfacial area. The interlayer is composed of B4C, SiO2, glassy carbon, amorphous B 2O3, and borosilicate glass. SiC appears in the interlayer of the joint heat-treated at 1400 °C for 30 min in vacuum. The addition of B4C and SiO2 powders contributes to the densification of the interlayer, the bonding at the interfaces and the heat resistance of the joints. © 2010 Springer Science+Business Media, LLC. Source


Li S.,Beihang University | Chen X.,Beihang University | Chen Z.,Avic xiAn Aviation Brake Technology Co.
Carbon | Year: 2010

Joining of carbon fiber reinforced carbon matrix composite to a carbon fiber reinforced C-SiC dual matrix composite has been realized through a reaction joining process using boron-modified phenolic resin with micro-size B4C and nano-size SiO2 powder additives. The effect of the heat-treatment temperature on the retained strength of the joints, calculated by dividing the strength of the heat-treated joints by the strength of the joints before heat-treatment, was studied. The maximum retained strength of the joints is 91.9% after heat-treatment at 1200 °C for 30 min in vacuum, indicating good heat-resistance of the joints. The interlayer with a thickness of about 25 μm is uniform and densified. There are no obvious cracks or pores at the interfaces. The interlayer is composed of B4C, SiO 2, glassy carbon, B2O3 and borosilicate glass. Si diffuses from the interlayer into the substrates and reacts with carbon to form SiC. Both B and O migrate from the interlayer into the substrates, contributing to the interfacial bonding. The B4C and the SiO 2 powder additives contribute to the densification of the interlayer, the bonding at the interfaces and the heatresistance of the joints. © 2010 Elsevier Ltd. All rights reserved. Source


Lu H.,Avic xiAn Aviation Brake Technology Co. | Zhang J.,Avic xiAn Aviation Brake Technology Co. | Liu L.,Avic xiAn Aviation Brake Technology Co. | Pei G.,Avic xiAn Aviation Brake Technology Co.
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2014

The friction agent is one of the critical factors of P/M aviation brake materials. The Cu-based friction materials were prepared by powder metallurgy technique. The effect of SiO2 particle size (38-48 μm, 48-75 μm, 61-106 μm, 75-150 μm, 106-212 μm) were studied. The research demonstrates that the SiO2 particle size has no significant impact on the density and hardness of material; with the increase of SiO2 particle size, the friction coefficient and wear rate are decreased, and the moment curve trends to smooth and steady at the same condition. Source


Li L.,Avic xiAn Aviation Brake Technology Co. | Liu L.,Avic xiAn Aviation Brake Technology Co. | Lu H.,Avic xiAn Aviation Brake Technology Co. | Pei G.,Avic xiAn Aviation Brake Technology Co.
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2016

The Fe-based friction materials with SiC particles were prepared by cold-pressing and pressure sintering method. The effect of SiC particle size (485 μm~, 250~830 μm, 180~380 μm, 150~180 μm, 75~150 μm, ~120 μm) on the density, hardness, friction and wear properties was studied. The research demonstrates that the SiC particle size has no significant impact on the density, hardness and associativity of materials, with the decrease of SiC particle size, the hardness, Minimum friction coefficient, maximum friction coefficient and the average friction coefficient of Fe-based friction materials decrease, the wear rate and the torque curve fluctuation increase; Fe-based powder metallurgy friction materials exhibit more excellent friction and wear performance with SiC particle size of 180~830 μm. © 2016, University of Science and Technology Beijing. All right reserved. Source

Discover hidden collaborations