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Liu G.,Xian Jiaotong University | Ni C.,Xian Jiaotong University | Xiao Q.,Beijing Baimtec Material Co. | Jin F.,Xian Jiaotong University | And 2 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering

A novel type of ceramic composite armor, metal-encased SiC ceramic armor with interpenetrating structure, was fabricated using a composite process, including preparation of reaction bonded SiC ceramic plate with ordered holes and metal casting of the macro-porous ceramic plate. The interface microstructures and elemental distributions or compositions of three different metals (a steel and two Ti alloys)/SiC composite armors were analyzed by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Relatively good interfacial bonding between ceramic and metal components was obtained, which is closely related to interfacial interactions and compressive residual stress on the ceramic during the cooling stage of casting. The interface microstructures depend significantly on the metal component composition (including the main element and the state of its existence after casting) and the casting process. Copyright © 2011, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved. Source

Wu F.-Q.,Beijing Baimtec Material Co. | Zhang B.-F.,Beijing Baimtec Material Co.
Cailiao Gongcheng/Journal of Materials Engineering

The used carbon-carbon (C/C) composite softened on surface to different levels due to oxidation. The surface Shore hardness (HS) and oxidation resistance of the used C/C composite samples after anti-oxidation treatment were measured. The results show that the samples with the hardness of HS70 increased to HS80 after recoating, and the mass loss ratios were 0.44%/15 h and 1.2%/22 h after oxidized at 700°C in air. The surface layer within 1 mm was softener than the substrate for the oxidized C/C composite sample with the hardness of HS40, and the hardness increased from HS40 to HS60 with a mass loss ratios of 3.93%/15 h and 6.52%/22 h at 700°C in air after recoating. Source

Shi C.,Beijing Baimtec Material Co. | Gao F.,Beijing Baimtec Material Co. | Yan J.,Beijing Baimtec Material Co.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys

Through an analysis of process requirements in specifications of titanium alloy castings (Ti-6Al-4V) which were selected from both at home and abroad, the differences and references among those specifications were investigated systematically. The vesults show that the domestic master heat can use revert materials as abroad to reduce cost. The differences among chemical components were focused on the elements of Al, H, Si. Especially the foreign specifications of aircraft engineering claimed more severe upper limit for Si and Y elements. After comparing mechanical properties, it is found that the ultimate tensile strength (UTS), yield strength (YS) of domestic standards are 30 MPa, 48~75 MPa higher than the requirements of Snecma and GE, respectively. The facts suggest domestic specification to reduce the strength requirements. The domestic applicable feature thickness range for ASTM E192 reference plate needed to conform to standards abroad. ASTM E1320 reference radiographs for titanium castings should be popularized to titanium castings as X-ray inspection standards. Source

Wu F.-Q.,Beijing Baimtec Material Co. | Zhang B.-F.,Beijing Baimtec Material Co. | Jiang H.,Beijing Baimtec Material Co. | Li D.-S.,Beijing Baimtec Material Co.
Cailiao Gongcheng/Journal of Materials Engineering

The influence of protective coatings formed of micron silicon dioxide (SiO2) and nanometer silicon dioxide (SiO2) on the anti-oxidation property of carbon/carbon composite, with the content of 6%, 12%, 18% and 24% percent respectively was investigated. And the components and the morphologies of protective coatings fore-and-aft-oxidation were also discussed contrastively with the X-ray diffraction (XRD) and the scanning electron microscope (SEM). The results showed that as the content of micron SiO2 increasing, ratios of oxidized mass loss on the carbon/carbon composite protective coating reduced first, then increased, whose best content was 18% with the ratio of oxidized mass loss of 0.38%. While as the content of nanometer SiO2 increasing, ratios of mass loss increased all along. The lowest ratio of oxidized mass loss was 2.88% with the smallest content of 6%. Source

Li Q.-C.,Beijing Baimtec Material Co. | Qin G.-J.,Beijing Baimtec Material Co. | Qiao Z.,Beijing Baimtec Material Co. | Liu D.-C.,Beijing Baimtec Material Co. | And 2 more authors.
Chinese Journal of Tissue Engineering Research

BACKGROUND: Posterior lumbar interbody fusion cage is one of the main means for the treatment of disc disease. The application of posterior lumbar interbody fusion can cause cage subsidence and other complications due to improper design, besides improper indication selection and improper surgical operation. OBJECTIVE: To optimize the cage design by reviewing the development of cage and concluding the other scholars' biomechanical research on the application of posterior lumbar interbody fusion cage. METHODS: A computer-based searched was performed in CNKI full-text database for the articles on optimize design of posterior lumbar interbody fusion cage from January 1990 to February 2012. The key words were "posterior lumbar interbody fusion cage, sinkage, design, bone graft fusion, biomechanical". The literatures of irrelevant purpose and repetitive content were eliminated, and then 18 literatures were included and checked the Modern Spine Surgery and Spinal Internal Fixation Operation and other related books for further analysis. RESULTS AND CONCLUSION: After optimization, the cage implanted in the interbody could acquire sufficient strength, which can support the end-plate and prevent cage from the early subsiding within the vertebral body. At the same time, the optimization can greatly increase the fusion area, further reduce the stress shielding, improve the fusion rate, accelerate the fusion process, reduce the subsidence, displacement and other complications, and all this will get a satisfactory clinical effect. Source

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