材料期刊网

含Ti的SiC纤维的先驱体的合成

宋永才 , 陆逸 , 冯春祥

材料研究学报

通过聚碳硅烷与钛酸丁酯的反应,合成了含钛聚碳硅烷PTC-Ⅰ(Ti/Si 原子比=0.02—0.04)。PTC-Ⅰ的可纺性与熔点随Ti 含量增加而有规律地变化。由二苯基硅二醇与钛酸丁酯的反应,可制得低聚体的聚钛硅氧烷,将其与聚碳硅烷反应,可以合成具有更高Ti 含量的聚合物PTC-Ⅱ(Ti/Si 原子比=0.10)。PTC-Ⅰ与PTC-Ⅱ都具有良好的可纺性,以它们作为先驱体制得了含Ti 的SiC 纤维。

关键词: 复合材料 , polycarbosilane , polytitanocarbosilane , SiC fiber

Effects of Nitridation on Properties of SiC Fiber and Interface of Ti Matrix Composite

Nanlin SHI , Jiwei FENG , Yanfen GUO , Yuyin LIU , Z.X.Guo

材料科学技术（英）

Prenitridation of the TiBx coating surface of the Sigma SM1240 SiC fiber can form more stable compounds at the surface and obstruct the release of boron atoms into the Ti-based alloy matrix. The effect of nitridation on the tensile strength of the fiber was investigated in this work. Nitridation could degrade the tensile strength of the SiC fiber if the treating temperature and time are not optimized. The chemical reaction between the W core and SiC and the modification of fiber microstructure during the nitridation are responsible for the degradation in strength. The strength can be maintained by further optimization of the treating temperature and time. Therefore, stabilizing the surface of TiBx coating and hence the interface of the SiCf/Ti composite by the nitridation of the SiC fiber is a feasible technique for practical applications.

关键词: SiC fiber , null , null , null , null

Preparation of SiC Fiber Reinforced Nickel Matrix Composite

Lu Zhang

材料科学技术（英）

A method of preparing continuous (Al+Al₂O₃)-coated SiC fiber reinforced nickel matrix composite was presented, in which the diffusion between SiC fiber and nickel matrix could be prevented. Magnetron sputtering is used to deposit Ni coating on the surface of the (Al+Al₂O₃)-coated SiC fiber in preparation of the precursor wires. It is shown that the deposited Ni coating combines well with the (Al+Al₂O₃) coating and has little negative effect on the tensile strength of (Al+Al₂O₃)-coated SiC fiber. Solid-state diffusion bonding process is employed to prepare the (Al+Al₂O₃)-coated SiC fiber reinforced nickel matrix with 37% fibers in volume. The solid-state diffusion bonding process is optimized and the optimum parameters are temperature of 870°, pressure of 50 MPa and holding time of 2 h. Under this condition, the precursor wires can diffuse well, composite of full density can be formed and the (Al+ Al₂O₃) coating is effective to restrict the reaction between SiC fiber and nickel matrix.

关键词: SiC fiber

Microstructural Changes of Ti-6Al-4V Matrix by the Incorporation of Continuous SiC Fibers

Yuechun FU

材料科学技术（英）

In SiC(f)/Ti-6Al-4V composites, the microstructure of the matrix close to the fiber was different from that of the fiber-less material. Microstructure observations show that a layer of fine grains was located adjacent to the fiber, and more dislocations and faults were found in this region. Higher recrystallization nucleation rate due to the undeformed SiC fiber and thermal residual stress induced during cooling from the fabrication temperature caused the microstructural changes of the matrix. Hardness measurement indicates that the matrix in the fiber neighborhood was strengthened, and the strengthening effect decreased with distance away from the fiber.

关键词: Matrix strengthening , null , null , null

Analysis of Microstructure of Silicon Carbide Fiber by Raman Spectroscopy

Baohong JIN

材料科学技术（英）

The SiC fiber was prepared by chemical vapour depostion, which consists of tungsten core, SiC layer and carbon coating. The microstructure of the fiber was investigated using Raman spectroscopy, illustrating SiC variation in different region of the fiber. The result shows that the SiC layer can be subdivided into two parts in the morphologies of SiC grains; their sizes increase and their orientations become order with increasing distance from the fiber center. It is demonstrated that the mount of free carbon in the fiber is responsible for the variation of SiC grains in sizes and morphologies. The analysis of Raman spectra shows that the predominant β-SiC has extensive stacking faults within the crystallites and mixes other polytypes and amorphous SiC into the structure in the fiber.

关键词: Raman spectra , null , null , null

三级化学气相沉积法制备SiC纤维及拉伸性能测试

张荣军 , 杨延清 , 沈文涛

无机材料学报 doi:10.3724/SP.J.1077.2010.00840

以甲基三氯硅烷为先驱体, 用直流电热三级化学气相沉积法制备了带有碳涂层的钨芯SiC纤维, 测定了纤维的室温拉伸强度, 并用Weibull分布对纤维的拉伸强度进行了评价. 利用扫描电镜(SEM)、X射线衍射仪(XRD)和透射电镜(TEM)分析了纤维的断口形貌、相结构组成和W/SiC界面反应层的微观结构. 结果显示, 三级化学气相沉积法制备SiC纤维拥有两层β-SiC和均匀的表面碳涂层, 钨芯和SiC之间存在厚度约为0.35μm的界面反应层, 纤维的平均拉伸强度和Weibull模数分别达到3266MPa和16.3, 并对纤维的断裂机理进行了分析和讨论.

关键词: SiC纤维 , chemical vapor deposition , tensile strength , fracture morphology , Weibull modulus

界面改性对SiC_f/Cu基复合材料热膨胀性能的影响

罗贤 , 杨延清 , 黄斌 , 李建康 , 刘翠霞 , 陈彦

稀有金属材料与工程

研究了SiC_f/Cu基复合材料分别在有无Ti6Al4V界面改性涂层两种情况下的纵向热膨胀行为,并采用扫描电镜对热循环后的试样进行显微形貌观察.结果表明,界面结合强度对纤维增强金属基复合材料的纵向热膨胀行为有很大影响.对于没有Ti6Al4V涂层的复合材料,其热膨胀行为不稳定,在经历连续两次热循环后,其纵向均表现为正的残余应变,原因是基体发生了严重的界面脱粘、滑移和膨胀;而对于有Ti6Al4V涂层的复合材料,其纵向热膨胀系数明显减小,两次热循环后其尺寸保持稳定,纤维/基体界面结合也保持稳定.

关键词: 金属基复合材料 , SiC纤维 , 热膨胀系数 , 中间层 , 界面结合强度

碳化硅纤维增强体钛铝基体的原位合成与控制及其动力学解析

曲海涛 , 任学平 , 侯红亮 , 赵冰

稀有金属材料与工程

利用磁控溅射,采用钛靶和铝靶按照一定功率比在SiC纤维表面沉积钛与铝,制备SiC纤维的Ti-Al基复合先驱丝,按密排堆垛置于包套之中并经热等静压制备碳化硅纤维增强钛铝基试样.通过扫描电镜观察组织形貌,研究热等静压及真空热处理对组织结构、界面反应层的影响,应用XRD与能谱分析,研究磁控溅射功率对原子比的影响以及钛铝原位反应过程中相比例的变化规律,采用差示扫描量热法(DSC,differential scanning calorimetry)对钛铝反应进行动力学分析.结果表明,钛靶与铝靶的溅射功率直接影响钛铝的原子比,TC4和Al靶功率分别为l3和4.5 kW/m2,其铝含量为27at％; TC4和Al靶功率分别为13和8.3 kW/m2,其铝含量为49at％.此外,动力学研究表明,Al3Ti是钛铝反应的优先生成相,随着Al的扩散,逐渐形成TiAl、Al2Ti和Ti3Al,但经过Al的充分扩散,其最终形成的稳定相取决于钛铝的原子比,若原子比为1∶1,则最终形成TiAl相,且不同原子比区域形成的TiAl、Ti3Al可共存.

关键词: 碳化硅纤维 , 钛铝 , 原位合成 , 动力学 , 磁控溅射

SiCf/Ti-6Al-4V复合材料的断裂韧性

杨延清 , 罗贤 , 黄斌 , 李建康 , 陈彦

材料热处理学报

采用三点弯曲法测定了SiC纤维单向增强的Ti-6Al-4V复合材料的表观断裂韧性,讨论了界面反应对断裂韧性的影响.研究结果表明,在裂纹尖端塑性变形区的未断纤维的桥联对复合材料的断裂韧性起很大的作用.经过热处理后,SiCf/Ti-6Al-4V复合材料的断裂韧性降低,主要是由于严重的界面反应,使得SiC纤维受到一定的损伤,因而降低了纤维的承载能力,并使基体钛合金的脆性增大.

关键词: 复合材料 , SiC纤维 , Ti-6Al-4V , 断裂韧性 , 界面反应

Effects of Nitridation on Properties of SiC Fiber and Interface of Ti Matrix Composite

材料科学技术（英）

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