材料期刊网

AN IN SITU STUDY ON DEFORMATION TWINNING NEAR CRACK TIP IN TWO-PHASE TiAl-BASE ALIOY

W Liang~1 , 2) , Q. Li~2) and D.ZYang~2)(Centre of Measuring and Testing Taiyuan University of Technology , Taiyuan 030024 , China Institute of Materials Science and Engineering , Harbin Institute of Technology , Harbin 150001 China Manuscript received 13 November 1995)

金属学报(英文版)

An in situ study of twinning at crack tip in a TiAl-base alloy has been performed.The result shows that twinning with long shear vector(2/6) [112] can generate on(111) plane, even though usually it is very difficult to occur because of the high energy barrier. It was further shown that (1/6) [112](111) twinning is considerably easier to generate. Furthermore,(1/2)<110) ordinary dislocations were very active and dominated nearly the whole plastic zone, in spite of low Schmid factors. On the other hand, however <101) and (1/2) <112] superdislocations with higher Schmid factors can hardly be observed.

关键词: :TiAl-base alloy , null , null

CuCr25W1Col合金的性能研究

赵峰 , 杨志懋 , 丁秉钧

稀有金属材料与工程

为节约Cr资源,提高CuCr触头材料的耐电击穿性能并满足其大规模生产的需要,根据W、Co的选择相强化作用, 以纯Cu、Cr块为原料, 采用Ar气保护熔炼法制备CuCr25W1Col触头合金,并对其性能进行研究.实验结果表明,该合金晶粒尺寸细小,含气量低,耐电压强度已达到常规触头材料的水平.

关键词: CuCr触头材料 , 选择相强化 , 耐电压强度

PROPERTIES OF W/Cu FGMS CONTAINING 1%TiC OR 1%La2O3 PREPARED USING GSUHP

K. Zhang , W.P. Shen , C.C. Ge , null , null

金属学报(英文版)

W / Cu functionally gradient materials (FGMs) containing 1% La2O3 and 1% TiC were prepared using graded sintering under ultra-high pressure (GSUHP). The specimens have been found to exhibit low porosity (11.57% and 11.35%, respectively). Shearing strength of the specimens between layers is good. Moreover, the specimens have still demonstrated good performance in testing thermal-shock resistance. When power density of laser is 200MWm-2, the specimens have been tested for thermal-shock resistance (1000 times); the specimens that contained 1% La2O3 were not subjected to damage, whereas those that contained 1% TiC began to crack. Finally, effect of additives on thermal-shock resistance was also preliminarily discussed.

关键词: W/Cu , null , null , null

(1-x)Pb(Fe_2/3W_1/3)O₃-xPb(Mg_1/2W_1/2)O₃多铁性材料的有序结构及磁性能

姚春发 , 李财富 , 刘志权 , 尚建库

无机材料学报 doi:10.3724/SP.J.1077.2011.00649

以无机盐为前驱体, 利用溶胶?凝胶法固溶合成了(1-x)Pb(Fe_2/3W_1/3)O₃-xPb(Mg_1/2W_1/2)O₃多铁性固溶体. XRD分析表明, 在0≤x≤1.0的掺杂范围内, 700℃煅烧所得产物都具有钙钛矿结构; x=0时得到的纯Pb(Fe_2/3W_1/3)O₃为长程无序结构, x=1.0时可获得完全有序的纯Pb(Mg_1/2W_1/2)O₃相, 其单胞为Pb(Fe_2/3W_1/3)O₃单胞的2倍; 当0<x<1.0时, (1-x)Pb(Fe_2/3W_1/3)O₃-xPb(Mg_1/2W_1/2)O₃固溶体也为有序结构, 出现1/2 (111)及1/2 (311) XRD衍射峰, 且强度随掺杂系数x的升高逐渐增大. TEM分析证实, 煅烧产物为具有钙钛矿结构的单相固溶体, 而非两相复合物; 固溶相形貌以立方颗粒为主, 随掺杂量增加其晶胞常数线性增大, 而晶粒尺寸先减小后变大. 性能测试发现, 固溶相的磁学性能随x的增加而逐渐下降, 起因于抗磁性的Pb(Mg_1/2W_1/2)O₃破坏了Pb(Fe_2/3W_1/3)O₃原有的价键结构所致.

关键词: 多铁性材料 , perovskite , Sol-Gel , ordering , magnetic property

(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3多铁性材料的有序结构及磁性能

姚春发 , 李财富 , 刘志权 , 尚建库

无机材料学报 doi:10.3724/SP.J.1077.2011.00649

以无机盐为前驱体,利用溶胶-凝胶法固溶合成了(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3多铁性固溶体.XRD分析表明,在0≤x≤1.0的掺杂范围内,700℃煅烧所得产物都具有钙钛矿结构;x=O时得到的纯Pb(Fe2/3W1/3)O3为长程无序结构,x=1.0时可获得完全有序的纯Pb(Mg1/2W1/2)O3相,其单胞为Pb(Fe2/3W1/3)O3单胞的2倍;当0＜x＜1.0时,(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3固溶体也为有序结构,出现1/2(111)及1/2(311)XRD衍射峰,且强度随掺杂系数x的升高逐渐增大.TEM分析证实,煅烧产物为具有钙钛矿结构的单相固溶体,而非两相复合物;固溶相形貌以立方颗粒为主,随掺杂量增加其晶胞常数线性增大,而晶粒尺寸先减小后变大.性能测试发现,固溶相的磁学性能随x的增加而逐渐下降,起因于抗磁性的Pb(Mg1/2W1/2)O3破坏了Pb(Fe2/3W1/3)O3原有的价键结构所致.

关键词: 多铁性材料 , 钙钛矿结构 , 溶胶-凝胶 , 固溶有序 , 磁性能

锻造态W-1％La2O3合金的纳米颗粒相分析

许志强 , 沈寅忠 , 崔凯 , 季波 , 郭新秋

稀有金属材料与工程

利用透射电子显微镜对锻造状态W-1％La2O3合金的相,特别是纳米尺度颗粒相,进行了分析.共发现8种颗粒相,包括:3种类型的La2O3相;2种类型的WO3相;W3O8相;La0.14WO3相以及(La2O3)sWO3相.其中La2O3、WO3和W3O8为合金中主要的纳米颗粒相,这些颗粒的尺寸主要集中在20～100 nm范围内.同时讨论了W-1％La2O3合金颗粒相的可能形成过程.

关键词: W-1％La2O3合金 , 锻造态 , 纳米颗粒 , 透射电子显微镜

W1?xAlxN复合膜的显微组织和抗氧化性能

肖晓 , 姚琲

中国有色金属学报(英文版) doi:10.1016/S1003-6326(17)60124-9

采用反应磁控溅射仪制备一系列不同铝含量(0~38.6%,摩尔分数)的W1?xAlxN复合膜.利用EPMA、XRD、XPS、纳米压痕仪、SEM及HRTEM等对膜组成、显微组织、力学及抗氧化性能进行表征,研究Al含量对WAlN膜显微组织和抗氧化性能的影响.结果表明,WN膜为面心立方结构,W1?xAlxN膜由面心立方W(Al)N和六方纤锌矿结构AlN组成,具有很强的(111)和(200)取向.其硬度随Al含量增加先增大后减小.当Al含量为32.4%(摩尔分数)时硬度达到最大值,为36 GPa.与WN相比,W1?xAlxN膜表现出更优的抗氧化性能,这主要归因于表层形成的致密Al2O3层.

关键词: W1?xAlxN膜 , 显微组织 , 硬度 , 抗氧化性能 , Al2O3层

Thermal transport properties and electronic structure of W-doped rubidium blue bronzes Rb(0.3)Mo(1-x)W(x)O(3) (x=0, 0.001, 0.003, 0.005)

Physica B-Condensed Matter

The thermoelectric power (TEP), electrical resistivity and X-ray photoemission spectrum (XPS) of the W-doped rubidium blue bronzes Rb(0.3)Mo(1-x)W(x)O(3) (x=0, 0.001, 0.003, 0.005) were investigated. It is shown that the Peierls transition is suppressed with the increase in the concentrations of the doped W ions. The sign change of the TEP was observed for all the samples. At low temperature below the Peierls transition, the W-doping makes the obvious decrease in the absolute values of TEP, especially for Rb(0.3)Mo(1-x)W(x)O(3) (x=0.003, 0.005). Furthermore, as compared with the pure blue bronzes, the enlarged difference between Peierls transition temperature (T(p)) and the sign changed temperature (T(s)) in Rb(0.3)Mo(0.999)W(0.001)O(3) bronzes was observed and discussed in detail. (C) 2010 Elsevier B.V. All rights reserved.

关键词: Charge density wave;Blue bronze;Thermoelectric power;Resistivity;charge-density-wave;thermoelectric-power;oxide bronzes;k0.3moo3;transition;scattering;rb0.3moo3;state;impurities;k0.30moo3

离心铸造Ti47Al2Nb1Cr1W0.2Si合金汽车气阀的铸造特性

马颖澈 , 熊超 , 陈波 , 高明 , 刘奎

稀有金属材料与工程

采用等温淬火与金相观察相结合的方法研究了离心铸造Ti47Al2Nb1Cr1W0.2Si合金的凝固特征.确定了合金的固、液相线温度分别为1465和1520℃.应用一次真空感应熔炼离心铸造气阀,获得过热度对气阀成型性及氧含量的影响规律,确定了使气阀获得良好成型且氧含量低的最佳过热度为160℃.

关键词: 等温淬火 , 固相线 , 液相线 , 过热度 , 离心铸造 , 气阀

W-1％La2O3合金的显微组织分析

崔凯 , 沈寅忠 , 俞杰 , 季波

稀有金属材料与工程

通过X射线衍射仪、光学显微镜、扫描电镜、透射电镜对聚变堆面向等离子体候选材料W-1％ La2O3合金的显微组织进行了研究.结果表明:与纯钨相比,添加了1％ La2O3的钨合金组织致密,孔隙与晶界裂缝消失,大量颗粒弥散在钨合金基体上.进一步的化学成分分析并结合电子衍射花样发现,在这些颗粒中不仅存在La2O3以及钨的氧化物,还存在一种镧的钨酸盐La2(WO4)3及非晶态颗粒.同时讨论了W-1％ La2O3合金的韧性和存在颗粒的可能形成过程.

关键词: 钨合金 , 氧化镧 , 显微组织特征 , 相分析