Author S.R. Zhou
,
S.R. Qiao
,
S.H. Bai and C.S. Tian Faculty 401
,
Northwestern Polytechnical University
,
Xian 710072
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
The tensile properties of three different carbonfiberreinforced carbon composites (C/C), mat C/C, 2D laminate and 4D C/C, were investigated under the combined influence of temperature and loading rate. From the experiments the following could be concluded: loading rate between 10-1-10 mm/min was valid; the fracture stress of the three kinds of C/C composites increased with increasing temperature in the range from room temperature to 1900, and the initial modulus of 2D laminate C/C composites increased with the increase of temperature up to 2000.
关键词:
tensile testing
,
null
,
null
,
null
陈庆军
,
魏丹丹
,
周贤良
,
晏建武
,
华小珍
,
艾云龙
稀有金属材料与工程
采用差热分析法(DTA)研究了具有高玻璃形成能力的Fe41Co7Cr15Mo14Y2C15B6块体非晶合金的变温晶化动力学.由热分析曲线得到玻璃转变温度Tg、晶化起始温度Tx和晶化峰值温度Tp1、Tp2,这些特征温度具有明显的动力学效应.运用Kissinger法和Ozawa法分别计算出不同升温速率下该Fe基块体非晶合金的玻璃转变激活能Eg、晶化激活能Ex与激活能Ep1、Ep2.采用Kissinger方法和Ozawa方法解释了此大块非晶合金具有高的热稳定性的热力学机制.
关键词:
块体非晶合金
,
变温晶化动力学
,
玻璃形成能力
,
激活能
,
热稳定性
孙乐
,
方向青
,
孟广慧
材料科学与工程学报
doi:10.14136/j.cnki.issn 1673-2812.2016.05.027
通过化学气相渗透(CVI)、树脂浸渍/碳化(I/C)的工艺制成多孔的C/C预制件,采用气体压力浸渗方法向预制体中渗入铜,制备出C/C-Cu复合材料.以高密度C/C复合材料(1.9g/cm3)作为对比样,在MM-200型磨损试验机上对其摩擦磨损性能进行测试,并对其微观结构和摩擦磨损机理进行分析.研究结果表明:C/C-Cu的摩擦系数比C/C复合材料的低,这主要与摩擦表面的摩擦膜有关,铜在摩擦力带动下填充摩擦表面的凹坑,并与碳材料共同形成摩擦膜,摩擦膜的碳含量越高,润滑效果越好.当C/C预制件密度为1.59 g/cm3时,C/C-Cu的摩擦系数和磨损量均小于C/C复合材料,摩擦磨损性能良好.
关键词:
C/C-Cu
,
摩擦磨损
,
摩擦膜
Physical Review B
We report the electronic transport properties of a composite system comprising zero dimensional superconducting NbC(C) nanocapsules and carbon nanofiber matrix. DC susceptibility measurements of the nanocomposite indicate that the critical temperature (T-C) of NbC nanocrystals is 10.7 K. The temperature dependence of electrical resistivity of the specimen pellet follows the Mott's T-1/4 law in a temperature range between T-C of NbC and 300 K, owing to a strong degree of structural disorder in the carbon matrix. Below the T-C of NbC, when the change of its electrostatic energy Delta E is far greater than the thermal energy, an electron will be localized on an isolated NbC nanocrystal at very low temperatures, leading to "Coulomb Blockade." As a result, a collective behavior of the single-electron tunneling effect takes place in a three-dimensional granular superconductors' network composed of the NbC/carbon/NbC tunneling junctions. The superconducting gap of NbC crystals is not found in the current-voltage curves, due to the suppression of surface superconductivity through the contact between NbC and carbon shells.
关键词:
zero-dimensional superconductor;granular metal-films;particles;conduction;nanocapsules;percolation;samples
材料科学技术（英文）
Oxidation behavior of C/C-SiC gradient matrix composites and C/C composites were compared in stationary air. The results show that oxidation threshold of C-SiC materials increases with the amount of SiC particles in the codeposition matrix. Oxidation rate of C/C-SiC gradient matrix composites is significantly lower than that of C/C material. The micro-oxidation process was observed by SEM.
关键词:
carbon carbon composites
Jingyi DENG
,
Wenchuan LIU
,
Haifeng DU
,
Huiming CHEN
,
Yiyi LI
材料科学技术（英文）
Oxidation behavior of C/C-SiC gradient matrix composites and C/C composites were compared in stationary air. The results show that oxidation threshold of C-SiC materials increases with the amount of SiC particles in the codeposition matrix. Oxidation rate of C/C-SiC gradient matrix composites is significantly lower than that of C/C material. The micro-oxidation process was observed by SEM.
关键词:
