材料期刊网，材料期刊，材料类期刊，材料期刊投稿

The thermomechanical analysis (TMA) of Cu_0.5Tl_0.5Ba₂Ca_2-xR_xCu₃O_10-δ, where R=Pr and La, with 0.0≤x≤0.15, was carried out in temperature range from 450 to 1145 K. The samples were prepared by single-step solid state reaction technique. The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The superconductivity of the prepared samples was investigated by electrical resistivity measurement. The results showed that low substitution content enhanced the (Cu_0.5Tl_0.5)-1223 phase formation, while the higher substitution content degraded this phase. The higher superconducting transition temperatures T_c were found to be 114 K and 109 K at x= 0.025 for Pr- and La-substitutions, respectively. The average linear thermal expansion coefficient increased as x increased, while the shrinkage temperature decreased as x increased. Those results were emphasized by porosity and Vickers microhardness calculations. Debye temperature θD was calculated from the linear thermal expansion coefficient data and correlated to T_c to estimate the electron-phonon coupling λ_ep.

关键词: (Cu_0.5Tl_0.5)-1223

激光快速制备Tix Aly-TiN复合涂层

靳振西 , 张成成 , 邓国坚 , 张显程 , 王正东

航空材料学报 doi:10.11868/j.issn.1005-5053.2016.5.008

采用激光气体氮化与同步送粉相结合的工艺方法,在Ti-6Al-4V合金表面原位合成了Tix Aly-TiN复合涂层。通过XRD,SEM,OM,EDS,显微硬度测试等手段研究了该复合涂层的物相组成、显微组织、元素分布及显微硬度。结果表明：涂层主要由TiN和Tix Aly 金属间化合物组成；沿激光熔深方向TiN含量下降；Tix Aly 金属间化合物含量上升；涂层无裂纹和孔隙,厚度较均匀,涂层与基体间形成良好的冶金结合；沿激光熔深方向N、Al元素的分布均匀；涂层显微硬度得到显著提高,且从涂层到基体逐渐降低。

关键词: 激光气体氮化 , Tix Aly-TiN , 微观硬度 , 显微组织

溅射AlY涂层对Ni基合金氧化行为的影响

付广艳 , 孟德松 , 苏勇 , 祁泽艳 , 李雨莎

稀有金属材料与工程

为了研究溅射AlY涂层对合金高温氧化行为的影响,在某镍基合金表面上采用磁控溅射方法制备了AlY涂层,并研究了无涂层镍基合金、溅射AlY涂层的镍基合金以及经过预氧化的溅射AlY涂层镍基合金在1100℃空气中的氧化行为.结果表明,无涂层镍基合金形成了疏松、不完整的Al2O3、Cr2O3以及NiO的混合氧化膜,且发生了内氧化;溅射AlY涂层镍基合金形成了均一的α-Al2O3膜,比表面裸露的镍基合金具有更好的抗氧化性能.溅射AlY涂层试样经预氧化后在试样表面优先形成了保护性y-Al2O3膜,高温氧化时转变为致密的α-Al2O3膜,因此可进一步提高其抗氧化性能.稀土元素Y改善了Al2O3膜与基体的粘附性,提高合金的抗氧化性能.讨论了氧化膜的形成机理.

关键词: 磁控溅射 , AlY涂层 , 抗氧化性能 , 预氧化

Preparation of I_2 Clusters and Their Absorption Spectra

Zhaojun LIN , Zhanguo WANG , Wei CHEN and Lanying LIN(Lab. of Sendconductor Materials Science , Institute of Semiconductors , Chinese Academy of Sciences , Beijing 100083 , China)

材料科学技术（英文）

Samples have been prepared at different temperatures by loading I2 molecules into the cages of zeolite 5A, and the measurements of the absorption spectra have been carried out for the prepared samples. It is shown that I2 molecular clusters are formed in the cages of zeolite 5A,and it is also found that moIecuIar clusters which are bonded with intermoIecuIar forces have an important feature, namely, the intermolecular distance in molecular clusters can be changed on different preparing conditions and the blue shift of absorption edges can not be as the criterion of forming molecular clusters.

关键词:

Galvanostatic electrodeposition and microstructure of copper (I) oxide film

Materials Research Innovations

Polycrystalline copper (I) oxide films were deposited on stainless steel substrate by galvanostatic electrodeposition method and were characterized by Xray diffraction and scanning electron microscopy. The effect of bath temperature, bath pH and current density on the compositon, grain size, surface texture and surface morphology of the electrodeposited films were investigated. The films deposited at low bath pH (less than or equal to 7) consisted of copper (I) oxide and metallic copper; while the films deposited at bath pH between 8 and 12 and bath temperature of 60 degrees C were pure copper (I) oxide. The preferred orientation of the copper (I) oxide films depended on the relative growth rate of (111) and (200) faces and could be controlled by adjusting the bath pH and/or the cathodic current density. (100)-oriented copper (1) oxide films could be deposited at pH=9 and current densities in the range of 0.25-1 mA/cm(2) while (111)-oriented films could be prepared at pH=12 or at pH=9 using the current densities between 1.5-2.5 mA/cm(2). Computer simulated crystallite shapes showed that the crystal shape changed from octahedral for (100)-oriented film to trucated pyramids and cubs for (111)-oriented film. And they were approved by scanning electron microscopy.

关键词: copper(I) oxide;electrochemical deposition;thin films;microstructure;electrochemical synthesis;thin-films

Mode I and mixed mode I/II fatigue cracking in Ni3Al(CrB) single crystals

Fatigue & Fracture of Engineering Materials & Structures

Nominal mode I and mixed mode I/II fatigue tests were carried out using the intermetallic compound Ni3Al(CrB) in the form of single crystal specimens. The effects of crystal orientation and load mode on fatigue crack initiation and growth were studied. The fracture surfaces of the single crystals were characterized by a cleavage-like appearance and cracking occurred either on a single {111} plane or on multiple {111} planes irrespective of whether mode I or mixed mode I/II loadings were applied. It was found that the crack initiation and growth behaviour are dependent on both crystal orientation and applied loading mode. The cracking behaviour predicted by three mixed mode fracture criteria (MTS, SED and G criteria) in polycrystalline materials under mixed mode loading can be understood from the present results on single crystals.

关键词: fatigue cracking;mixed mode loading;crystallographic orientation;resolved shear stress;Ni3Al(CrB) single crystals;growth;alloy

正常形变带[521]1/2的ΔI=1颤动

吴崇试 , 潘奕

原子核物理评论 doi:10.3969/j.issn.1007-4627.2002.01.001

系统分析了A≈170区正常形变带[521]1/2-中的ΔI=1颤动现象. 根据旋称伙伴带的跃迁能量提取Δ2 Eγ (I)=[Eγ(I)+Eγ(I-2)]/2-Eγ(I-1)值, 表现出旋称相关的规则上下颤动. 其颤动幅度在低自旋端约为50 keV, 而后随自旋而增大或减小, 大体呈抛物线形. 利用改进的ab公式, 提取了相关的脱耦合系数. 运用Nilsson波函数, 探讨了原子核集体哈密顿量中高阶微扰项的可能形式.

关键词: 正常形变带 , 旋称伙伴带 , ΔI = 1颤动 , 脱耦合效应 , 改进的ab拟合

采用UF法精制I+G产品

张国俊 , 许赵辉 , 刘忠洲

膜科学与技术 doi:10.3969/j.issn.1007-8924.2002.02.010

采用截留分子量(MWCO)1万的卷式超滤膜和截留分子量(MWCO)6 000的中空纤维超滤膜,去除I+G粗品液中影响I+G产品透光的色素、大分子蛋白及可溶性胶体蛋白,不需加碳、压滤等工序,产品透光合格率达100%,产品透光的合格稳定性较现有生产工艺大大提高,该工艺不仅可以省去加碳压滤等工序,而且可以保证产品一次性达到合格产品.

关键词: 肌苷酸 , 鸟苷酸 , 超滤 , 透光