材料期刊网

装甲级Al?Zn?Mg合金搅拌摩擦焊接接头的力学性能

C.SHARMA , V.UPADHYAY , D.K.DWIVEDI , P.KUMAR

中国有色金属学报(英文版) doi:10.1016/S1003-6326(17)60056-6

研究焊接速度和旋转速度对装甲级铝合金搅拌摩擦焊接接头的形成和力学性能的影响.采用弯曲试验、显微硬度测试、力学性能测试、光学显微镜和扫描电子显微镜对焊接接头进行表征.焊接接头的力学性能(包括显微硬度、抗拉强度和伸长率)随旋转速度增加而增加,随焊接速度减小而增加.焊接速度对热影响区显微硬度的影响比旋转速度更强.焊接速度和旋转速度对搅拌摩擦焊接接头的力学性能有重要影响,且其影响可用回归模型进行预测.

关键词: 搅拌摩擦焊 , 焊接参数 , 力学性能 , 断裂形貌 , 回归模型

TENSILE TESTING OF C/C COMPOSITES ATHIGH TEMPERATURES

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

C/C-PAA与C/C-FA弯曲性能对比

张万强 , 赵英民 , 王涛 , 詹万初

宇航材料工艺 doi:10.3969/j.issn.1007-2330.2014.05.012

通过PIP工艺制备了C/C-PAA、C/C-FA复合材料,对PAA、FA裂解碳的XRD、浸渍效果以及C/C-PAA和C/C-FA的弯曲强度进行了分析.结果表明:PAA裂解碳的炭质量、浸渍效果较好,C/C-PAA弯曲强度比C/C-FA弯曲强度高34.9％,弯曲模量对比不明显.

关键词: 聚芳基乙炔 , 糠酮树脂 , X射线衍射 , C/C复合材料

偏光观察C/C复合材料

张保法 , 阮宏武 , 李东生

材料工程 doi:10.3969/j.issn.1001-4381.2006.01.008

利用正交偏光可分辨C/C复合材料中不同类型的沉积炭,通过旋转检偏器可测量C/C复合材料中沉积炭的消光角度.列举了偏光观察C/C复合材料实验过程中经常遇到的问题,介绍了测定消光角度的方法,简要概述了近年来研究热解炭各向异性的成果.

关键词: C/C复合材料 , 化学气相沉积 , 消光角度 , 偏光显微镜

C/C及C/C-Cu复合材料的摩擦磨损性能

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

Electronic transport properties of NbC(C)-C nanocomposites

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

Oxidation behavior of C/C-SiC gradient matrix composites

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

Oxidation behavior of C/C-SiC gradient matrix 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:

C/C-SiC摩擦材料的研究进展

李波 , 崔园园 , 李爱军 , 周春节 , 张家宝 , 白瑞成

上海金属

综述了C/C-SiC摩擦材料的研究现状,以及C/C-SiC摩擦材料的发展历程.详细分析C/C-SiC摩擦材料的摩擦磨损性能影响因素及机理,介绍了C/C-SiC摩擦材料的改性及应用现状,并对未来的研究重点进行了展望.

关键词: C/C-SiC摩擦材料 , 摩擦磨损性能 , 机理 , 改性

INTERACTION BETWEEN C AND Sb IN Fe-C-Sb LIQUID SOLUTION

ZHOU Qianli DU Ting Central Iron and Steel Research Institute , Ministry of Metallurgical Industry , Beijing , China DU Ting Senior Engineer , Laboratory No.16 , Central Iron and Steel Research Institute , Ministry of Metallurgical Industry , No.76 Xueyuannanlu , Beijing , China

金属学报(英文版)

The influence of Sb on the C solubility in liquid Fe was measured under 1300,1400 and 1500℃.The C solubility decreases with the increase of Sb content in liquid Fe.The tem- perature dependences of the first order interaction coefficients in C-saturated liquid Fe were determined as follows: *e_C~(Sb)=11.309/T+0.0025 *e_(Sb)~C=128.023/T-0.0219 The temperature dependences of interaction coefficients between Sb and C in dilute liquid Fe were given to be: e_C~(Sb)=14.204/T+0.025 e_(Sb)~C=120.541/T+0.227 ε_C~(Sb)=ε_(Sb)~C=6026.75/T+11.958 The interaction coefficients at 1600℃ are *e_C~(Sb)=0.0085,e_C~(Sb)=0.033,*e_(Sb)~C=0.295, ε_C~(Sb)=ε_(Sb)~C=15.36.The first order interaction coefficients vary slightly with the temperature.

关键词: Fe-C-Sb solution , null , null , null