材料期刊网

HARDENING OF L1_2-ORDERED Co_3Ti BY PRECIPITATION OF FCC-Co PHASE

W. H. Tian , S.L. Hu and M. Nemoto(Department of Materials Physics , University of Science and Technology Beijing , Beijing 100083 , China)(Department of Materials Forming , University of Science and Technology Beijing , Beijing 100083 , China)(Department of Materials Science and Engineering , Faculty of Engineering , Kyushu University , Fukuoka 812 , Japan)

金属学报(英文版)

The Co3 Ti phase hardens appreciably by the fine precipitation of disordered fcc Co-rich phase upon aging after quenching from solution annealing temperature. Transmission electron microscope (TEM)observations revealed that the precipitates are platelet in shape, lying nearly parallel to the {100} planes of the L12-ordered matrix, and perfectly coherent with the matrix lattice at the beginning of aging. The high temperature strength increases appreciably with the fine precipitation of disondered Co-rich phase over the whole temperature range investigated. TEM observations of the deformed alloys after underaging revealed that saperdislocations are pinned by precipitates indicating an attractive interaction between dislocations and precipitates.

关键词: Co_3 Ti , null , null , null , null

EFFECT OF Cr ADDITION ON MICROSTRVCTURES AND MECHANICAL PROPERLIES OF β-NiAl ALLOYS

W.H. Tian , S.L. Hu and M. Nemoto(1) Department of Materials Physics , University of Science and Technology Beijing , Beijing 100083 , China 2) Department of Materials Forming , University of Science and Technology Beijing , Beijing 100083 , China 3) Department of Materials Science and Engineering , Faculty of Engineering , Kyushu University , Fukuoka 812 , Japan)Manuscript received in revised form 12 October 1998

金属学报(英文版)

The effect of Cr addition on the microstructures and mechanical properties of NiAl inermetallic alloys containing 4 to 8 mol% Cr has been characterized. It is shown that Cr is not only an efficient soild solution strengthener in NiAl, it is also an efficient precipitation Strengthener by fine dispersion of α-Cr particles. Transmission electron microscope observations have revealed that fine spherical particles of α-Cr appeared homogeneously in the NiAl matrix by aging at temperatures around 1073K after solution annealing at 1563K. The aging behavior was investigated by microhardness measurements and the temperature dependence of the yield stress of NiAl containing α-Cr particles was investigated by compression tests over the tempemture range from 298 to 1173K. NiAl alloys happened appreciably by the precipitation of α-Cr particles.Dislocations bypass the particles during deformation and typical Orowan loops were observed surrounding the α-Cr particles after deformation. Although the dispersion Of α-Cr particles increases the yield strength of NiAl at intermediate temperutre, the strength decreases appreciably at higher temperatures.

关键词: NiAl , null , null , null , null

7075铝合金微等离子体氧化硼酸盐体系电解液配方的优化

苗景国 , 陈秋荣 , 郝康达 , 卫中领

表面技术 doi:10.3969/j.issn.1001-3660.2012.03.029

利用微等离子体氧化技术,在7075铝合金表面原位生成了陶瓷层.采用正交实验法确定了在硼酸盐体系中进行微等离子体氧化的最佳电解液配方,通过SEM及XRD分析了陶瓷层的形貌及相组成.结果表明:陶瓷层硬度可达到812HV0.1；陶瓷层表面形貌均匀,膜层致密,主要由γ-Al2O3组成.

关键词: 微等离子体氧化 , 陶瓷层 , 电解液配方 , 形貌

高温弹性镍铍钛合金带的研制

李永华 , 汪治军 , 闫永 , 张晨 , 黄志攀

稀有金属 doi:10.3969/j.issn.0258-7076.2003.01.018

采用真空中频熔炼、热加工轧制及热处理研制出符合航空要求的高温镍铍钛合金带. 并且各项性能达到了美国同类产品水平. 其力学性能, 固溶状态下: σb≤812 MPa, δ10≥30%, Hv≤250 kg*mm-2, 晶粒度≤0.055 mm; 固溶-时效状态下:σb≥1519MPa, δ10≥3%, Hv≥500 kg*mm-2.

关键词: 镍铍钛 , 熔炼 , 铸造 , 轧制 , 热处理

电化学暂态联机测试

林广 , 王建明 , 张鉴清等

腐蚀学报（英文）

利用ＰＬＣ－８１２接噪反的Ａ／Ｄ和Ｄ／Ａ功能，实现微机和国产非智能化恒电位仪之间的信息互通，组成电化学暂态测试系统，开发了基于ＷＩＮＤＯＷＳ操作平台的接口软件，实现快速、精确的数据采样；从软件出发实现多种有效的数字滤波方法，消减噪声干扰，并用模拟电路验证了测试系统的可靠性。　

关键词: 电化学 , transient measurement , canputer interface

电化学暂态联机测试

林广 , 王建明 , 张鉴清 , 乔亦男 , 曹楚南

腐蚀学报（英文） doi:10.3969/j.issn.1002-6495.2000.04.012

利用PCL-812接口板的A/D和D/A功能,实现微机和国产非智能化恒电位仪之间的信息互通,组成电化学暂态测试系统.开发了基于WINDOWS操作平台的接口软件,实现快速、精确的数据采样;从软件出发实现多种有效的数字滤波方法,消减噪声干扰.并用模拟电路验证了测试系统的可靠性.

关键词: 电化学 , 暂态测试 , 计算机接口 , 数字滤波

Nd3+:Na3La9O3(BO3)8晶体生长和光谱性能

白晓艳 , 张国春 , 傅佩珍

人工晶体学报

采用顶部籽晶法生长Nd3+:Na3La9O3(BO3)8 晶体.在室温下测试了吸收光谱、发射光谱和荧光寿命.应用Judd-Ofelt理论评价了Nd3+:Na3La9O3(BO3)8晶体的光谱性能.812 nm处较宽的吸收峰适合AlGaAs LD泵浦的吸收.分别计算了Nd3+离子的唯象强度、谱线强度、辐射寿命、荧光分支比和荧光量子效率.

关键词: Nd3+ , Na3La9O3(BO3)8晶体 , 晶体生长 , 光谱性能

掺钕KGW激光晶体的各向异性吸收光谱及其上转换发光

刘璟 , 郑志强 , 黄抒洁 , 李小燕 , 冯卓宏 , 洪锦棉 , 林琳 , 明海

人工晶体学报 doi:10.3969/j.issn.1000-985X.2006.04.050

在室温下测量了掺钕钨酸钾钆(Nd3+:KGW)晶体三个晶轴方向的吸收光谱,其吸收谱带强度明显显示各向异性.将Judd-Ofelt(J-O)理论进行修正,使其扩展应用于处理各晶轴方向的吸收光谱,计算出三个晶轴方向的各光谱带吸收系数、电偶极跃迁振子强度,其结果说明了Nd3+:KGW吸收光谱存在着各向异性.同时还研究了该材料在812nm激发下的上转换荧光特性,观察到较强的蓝色荧光.

关键词: Nd3+:KGW , 吸收光谱 , 各向异性 , 上转换发光

煅烧和除碳温度对氮化硼晶须的影响

赵林 , 张玉军 , 龚红宇 , 赵东亮

人工晶体学报

以三聚氰胺和硼酸为原料通过水浴加热合成晶须前驱体,然后经高温烧结成功制备出BN晶须.扫描电镜显示制备的BN晶须为针状结构,其直径和长径比分别为2～3 μm和40～100.通过X射线衍射分析,制备的BN晶须为六方晶相,晶格参数为a=0.2524 nm和c=0.6592 nm.红外光谱图谱表明在1383 cm-1和 812 cm-1处存在两个明显的B-N特征吸收带.晶须的烧成制度以及除碳温度对晶须形貌和性能的影响研究结果表明,当烧成温度为1700 ℃、除碳温度为600 ℃时可制备出形貌良好和结晶度高的氮化硼晶须.

关键词: 氮化硼晶须 , 煅烧 , 除碳工艺

Corrosion behavior of three iron-based model alloys in reducing atmospheres containing HCl and H2S at 600 degrees C

Corrosion Science

The corrosion of three Fe-xCr alloys (x = 8, 12, 18 wt.%) was examined at 600 C in reducing atmospheres containing HCI and H2S with two different H2S contents and compared with the behavior of the same materials in H2S-free H-2-CO2 and H-2-HCI-CO2 mixtures producing similar oxygen and chlorine pressures. Exposure to the low-H2S gas mixture had only a reduced effect on the behavior of Fe-8Cr and Fe-18Cr, but increased significantly the corrosion rate of Fe-12Cr. Increasing the H2S level accelerated the corrosion of all the alloys, but particularly that of Fe-18Cr. In both cases only minor amounts of sulfur and chlorine were present close to the alloy/scale interface. An increase of the Cr content reduced the corrosion rate in both HZS gas mixtures, especially in the range 812 wt.% Cr, due to a larger volume fraction of Cr2O3 in the scale. The results have been discussed on the basis of the thermodynamic stability diagrams of the Fe-O-Cl-S and Cr-O-Cl-S systems. (c) 2006 Elsevier Ltd. All rights reserved.

关键词: Fe-Cr alloys;reducing atmosphere;oxidation;HCl and H2S effects;high-temperature corrosion;fe-cr alloys;municipal incinerators;hydrogen-chloride;chromium-alloys;oxidizing atmospheres;fireside;corrosion;commercial steels;containing gas;fired boilers