材料期刊网

OXIDATION BEHAVIOR OF Ni_3Al AND NiAl ALLOYS CONTAINING Fe ADDITIONS

J.T.Guo , S.H. Wang , H. Li , W.H. Lai and M.H.Tan(Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China Manuscript received 26 August 1996)

金属学报(英文版)

The isothermal oxidation behavior of Ni_3Al containtng 15 at.% Fe and NiAl containing 30 at.% Fe was studied for 100 h at 850, 950, 1050 and 1150℃, respectively. The results show that the oxidation kinetics of the two alloys obey a parabolic law at various temperatures and every parabolic curve possesses two oxidation rate constants. The morphology, microstructure and the chemical composition of the oxide scales were examined using optical metallography, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. The oxide scale of Ni_3Al containing 15 at.% Fe consists mainly of NiO, NiFe_2O_4, and FeAl_2O_4, and that of NiAl containing 30 at.% Fe consists of Fe_2O_3 and (Fe,Ni)Fe_2O_4, contrasting sharply to the oxide scales of pure Ni_3Al and NiAl which consist of Al_2O_3. The oxide scales on the surfaces of Ni_3Al and NiAl containing Fe are not too dense and not too cohesive to the matrix,so their oxidation resistance is not too good.

关键词: :oxidation , null , null , null

MICROSTRUCTURE AND PROPERTIES OF SiC_w/6061Al COMPOSITE The Author is now with Institute of Metal Research,Academia Sinica,China

MA Zongyi YAO Zhongkai Harbin Institute of Technology , Harbin , China

金属学报(英文版)

The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure

关键词: composite , null , null , null

Catalytically enhanced dehydrogenation of Li-Mg-N-H hydrogen storage material by transition metal nitrides

Journal of Alloys and Compounds

Motivated by the understanding of dehyrogenation/rehydrogenation reaction mechanisms, we examine the effect of two commercial transition metal nitrides. TaN and TiN, oil the dehydrogenation performance of Li-Mg-N-H system. Both nitrides are catalytically active for accelerating the dehydrogenation reaction of this system. Such catalytic enhancement well persists without hydrogen capacity loss. A catalytic mechanism is proposed Willi reference to the catalytic, model for hydrotreating reactions by transition metal nitrides. (c) 2008 Elsevier B.V. All rights reserved.

关键词: Hydrogen absorbing materials;Nitride materials;molybdenum nitride;system;improvement;catalysts;mechanism;mixtures;hydride;imides;amide;linh2

Oxygen reduction mechanism on copper in a 0.5 M H(2)SO(4)

Electrochimica Acta

The mechanism of the oxygen reduction reaction (ORR) in a naturally aerated stagnant 0.5 M H(2)SO(4) Was studied using electrochemical methods. The cathodic polarization curve showed three different regions; electrochernical impedance spectroscopy (EIS) measurement was used accordingly. The EIS data were analyzed, and the mechanism for the ORR was proposed consequently. The three regions include a limiting current density region with the main transfer of 4e(-) controlled by diffusion (-0.50V < E < -0.40V), a combined kinetic-diffusion region (-0.40V

关键词: Oxygen reduction;Hump phenomenon;Chemical redox;Copper;Electrochemical impedance spectroscopy;sulfuric-acid electrolyte;anodic-dissolution;sulfate-solutions;corrosion;behavior;adsorption;chloride;cu(111);alloy;model

Effect of Phosphates on the Metal Ion Activated Surface Complexes at the SiO_2-H_2O Interface and in Quartz Deactivation in Flotation System

SUN Zhongxi W. Forsling CHEN Jin Division of Inorganic Chemistry , Lulea University of Technology , S-951 87 Lulea , SwedenDept.of Mineral Engineering , Central South University of Technology , Changsha , 410083 , ChinaTo whom correspondence should be addressed

材料科学技术（英文）

The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evaluate the mechanism,The calculation results revealed that in the presence of a certain amount of phosphates, metal ions adsorbed at the quartz-H_2O interface will be transferred into solution.Thus the competi- tion for metal ions between phosphates and the quartz surface leads to surface deactivation and re- duced floatability.Various distribution diagrams clearly demonstrate the change of surface complexation as a function of added phosphate concentration.The deactivation products were also evaluated.

关键词: complexation , null , null , null , null , null

不同金属基体上W-C:H溅射薄膜的摩擦学性能

郑军 , 周晖 , 杨拉毛草 , 张延帅 , 翟广泉

宇航材料工艺 doi:10.3969/j.issn.1007-2330.2015.01.015

采用非平衡磁控溅射技术在40Cr、9Cr18、GCr15、TC4及LY12等5种金属基体上沉积了钨掺杂含氢类金刚石(W-C:H)薄膜.采用Raman光谱仪、扫描电子显微镜、纳米硬度计及纳米划痕仪分别测试了薄膜的微结构、厚度、硬度及附着力,采用球-盘摩擦试验机及光学轮廓仪分别在干摩擦和PFPE脂润滑条件下评价了5种金属材料基体上薄膜的摩擦磨损性能.薄膜性能测试结果显示,该厚度为1μm的薄膜具有典型的类金刚石结构,硬度与弹性模量分别为11.56和128.34 GPa,附着力为645 mN;摩擦试验结果显示,在干摩擦条件下几种金属基体表面W-C:H薄膜的摩擦因数和磨损率差别比较显著,而在脂润滑条件下基体材料的影响较小;与干摩擦条件相比,脂润滑条件下薄膜的磨损可减少60％ ～75％;在干摩擦与脂润滑条件下,9Cr18与40Cr基体上的W-C:H薄膜摩擦体系分别具有最小的磨损率1.71×10-7 mm3/(N·m)及4.55×10-8 mm3/(N·m).

关键词: W-C:H薄膜 , 摩擦学 , PEPE润滑脂 , 力学性能 , 非平衡磁控溅射

C和W注入H13钢纳米结构和抗腐蚀特性

张通和 , 吴瑜光 , 易仲珍 , 张旭 , 梁宏 , 马芙蓉 , 王晓妍

材料热处理学报 doi:10.3969/j.issn.1009-6264.2001.03.015

用多次扫描电位法研究了C和W单独及双注入H13钢对抗腐蚀特性的影响、抗腐蚀相生成的条件及其对抗腐蚀特性的作用,对改性机理进行了讨论.实验结果表明,碳、钨单独和双注入H13钢钨和碳可在注入层超饱和分布,特征为类高斯分布.双注入可在注入层中形成弥散的碳化钨WC和W2C、中间相Fe2W、铁钨碳化物FeW3C、Fe6 W6C和铁的碳化物Fe5C3,Fe3C,Fe2C等.其形状为丝状纳米相,丝状相沿样品法线生长.这种结构使注入层强化,增强了表面抗腐蚀特性;钨和碳双注入同时具有钨和碳单注入的优势,能更有效地提高H13钢的抗腐蚀性,随着W和C注入剂量的增加,抗腐蚀特性逐步增强;样品W5C5的Jp经55个周期腐蚀后,约为H13钢Jp的1/30.

关键词: C和W注入 , 钢 , 抗腐蚀特性 , 电化学测量

Simulations of Coarsening Behavior for M23C6 Carbides in AISI H13 Steel

Xinbin HU , Mei ZHANG , Xiaochun WU , Lin LI

材料科学技术（英文）

Based on the local equilibrium assumption, coarsening behavior of M23C6 carbide at 700℃ in H13 steel was simulated by DICTRA software. The results from the calculations were compared with transmission electron microscopy (TEM) observations. The results show the interfacial energy for M23C6 in H13 steel at 700℃ is thus probably 0.7 J•m-2, which fits the experiments well. The influence of composition and temperature on the coarsening rate was also investigated by simulations. Simulations show a decrease in the coarsening rate when V/Mo ratio is increased, while the coarsening rate increases with increasing temperature.

关键词: DICTRA Simulation , 碳化物粗化 , 界面能 , H13钢

A Novel near Net-Shape Technique for P/M Parts with Large H/D Ratio

Yong LIU , Baiyun HUANG , Kechao ZHOU , Hongwu OUYANG , Yuehui HE

材料科学技术（英文）

In order to overcome the shortcomings of conventional hot pressing, a novel near net-shape technique, called radial hot pressing, for P/M parts with large height-to-diameter (H/D) ratio was introduced. Effects of processing parameters on the microstructures and density of P/M TiAl base alloy valves were studied. Results show that the radial hot pressing is an effective technique for manufacturing valves with a H/D ratio of about 10:1, and the perfect joint interface between the Mo sheet and the parts is helpful for subsequent HIPing.

关键词: Near net-shape technique , null , null

LF炉冶炼过程钢中w(H)控制的实践

王瑾 , 廖明 , 李斌

钢铁研究

在2008年重钢的探伤钢CDQ207生产中,钢中氢成为影响钢板探伤合格率的主要因素之一.通过加强合金烘烤、控制精炼环节原辅料水分等技术管理措施,强化LF过程w(H)控制,充分发挥LF精炼功能,确保了大部分炉次钢中w(H)控制在合理范围内.2009年1-10月探伤钢探伤综量合格率为95.93%,较好地完成了项目指标.

关键词: 探伤 , 控氢 , LF , 合金烘烤