材料期刊网，材料期刊，材料类期刊，材料期刊投稿

甲烷浓度对CVD金刚石薄膜晶体学生长过程的影响

朱宏喜 , 毛卫民 , 冯惠平 , 吕反修 , VlasovII , RalchenkoVG , KhomichAV

无机材料学报 doi:10.3724/SP.J.1077.2007.00570

采用X射线衍射技术、电子背散射衍射技术和扫描电镜分别观察了不同甲烷浓度条件下沉积的CVD自支撑金刚石薄膜的宏观织构、微区晶界分布和表面形貌. 研究了金刚石晶体{100}面和{111}面生长的晶体学过程. 研究表明, {100}面通过吸附活性基团CH22-, 而{111}面通过交替吸附活性基团CH3-和CH3-后脱氢堆积碳原子. 低甲烷浓度时, {111}面表面能低于{100}面, 使{111}面生长略快于{100}面. 甲烷浓度升高, 动力学作用增强使{100}面生长明显快于{111}面, 使金刚石薄膜产生{100}纤维织构; 同时显露的{100}面平行于薄膜表面, 竞争生长使位于晶体侧面的{111}面由于相互覆盖而减小, 形成了不同于单晶体自由生长的薄膜表面形貌组织.

关键词: 金刚石薄膜 , texture , crystalgrowing , surface structure

钢的离子氮化表层中的α相微晶结构

李冀 , 苑永生 , 苑珂琦

金属学报

对W18Cr4V,38CrMoAl,1Cr18Ni9Ti3钢种的离子氮化层进行了透射电镜观察,并对奥氏体不锈钢的离子氮化表层用Auger能谱进行了成分分析,由于离子轰击效应,在离子氮化表层形成了α相微晶结构,其中存在织构.在离子轰击渗扩过程中,1Cr18Ni9Ti奥氏体不锈钢的渗层的表层发生成分变化,Cr/Fe比升高,Ni/Fe比下降,所以也形成了α相微晶结构。

关键词: 离子氮化 , microcrystal , surface structure

Mysterious Waters at Metal Surfaces

Jibiao Li Shenglong Zhu Fuhui Wang

材料科学技术（英）

Molecular structures of adsorbed waters at metal surfaces are essential to understanding the widespread processes ranging from ice nucleation, to water involved catalytic surface reactions, to many phenomena of biological and astrochemical importance. Instead of providing a comprehensive literature survey, we focus in this review on detailed structural information, such as water orientations and occupation sites, of intact waters at low temperatures and ultrahigh vacuum conditions investigated by various surface techniques. Despite progresses made in direct imaging the surface waters at high resolutions, as exemplified in a close-packed (e.g. Pd(111)) and an open metal surfaces (e.g. Cu(110)) supported waters, structural mysteries remain at diverse metal surfaces. We highlight experimental challenges and discuss structural mysteries in elucidating surface
water structures at molecular levels.

关键词: Water monolayer , surface structure , transition metal surfaces

Surface Structure and High-frequency Magnetic Properties of the Amorphous [Co_(0.94-x)Fe_(0.06)(MoMn)_x]_(77)(SiB)_(23) Alloys

Lijun CHEN Yuzhi LIU Gingzhen XU Haisheng SHI Shanghai Iron and Steel Research Institute , Shanghai , 200940 , China

材料科学技术（英）

The relationship between the high-frequency magnetic properties and surface structure of the amorphous [Co_(0.94-x)Fe_(0.06)(MnMo)_x]_(77)(SiB)_(23) alloys annealed at 400-500℃ then control-cooled was investigated using XRD,TEM and XPS techniques.The results have shown that the high-frequency losses of the present alloys ob- viously reduced after suitable treatment.A crystalline layer with ultrafine grains of γ-Co formed on the surface of the amorphous ribbons.The size of the grains is 10-20 nm.The thickness of the layer is less than 0.1 μm.The sur- face of the crystalline layer is covered with an extremely thin oxide film which is very uniform and dense with thickness of less than 30 nm,the size of grains of the oxide is less than 10 nm.These ultrafine grains and the dense oxide film effectively refine the magnetic domains and increase the resistance of the layers of the magnetic core,consequently the losses at high frequency are fairly reduced.

关键词: magnetic property , null , null

ALPHA-PHASE MICROCRYSTALLINE STRUCTURE OF IONITRIDING LAYER ON STEELS

LI Ji YUAN Yongsheng Northeast University of Technology , Shenyang , ChinaYUAN Keqi University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

TEM observation on the ionitriding layer was carried out on steels W18Cr4V,38CrMoAl and 1Cr18Ni9Ti,and AES of elementary analysis was also made on the outer surface of ionitrid- ing layer of austenitic stainless steel.Perhaps due to the ion-bombardment effect,a microcrystalline structure with texture was affirmed along surface of the ionitriding layer.It may be affected by cathodic sputtering and absorption that the atomic ratio of Cr/Fe in- creases and of Ni/Fe decreases on surface of nitriding layer on austenitic stainless steel 1Cr18Ni9Ti,thus the α-phase microcrystalline structure occurrs.

关键词: ionitriding , null , null

脉冲参数对等离子电沉积镍镀层结构和性能的影响

赵广宏 , 何业东

材料热处理学报

采用高频脉冲电源在纯铜基材上以等离子电沉积技术制备出了金属镍镀层,研究了高频脉冲频率以及占空比变化对等离子镀镍层结构和性能的影响。对镀层进行了SEM,显微硬度以及划痕结合力的表征。结果表明,随着高频脉冲频率和占空比的增加,镀层表面的熔融态形貌逐渐减少,镀层逐渐变得致密,表面硬度与结合力值也相应提高。通过讨论脉冲电源的能量作用方式,分析了频率及占空比对等离子电沉积镍层表面结构及性能的影响规律。

关键词: 等离子电沉积 , 脉冲频率 , 占空比 , 镀镍层 , 表面结构

混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响

张云鹏 , 孙广标 , 张安洲

稀有金属材料与工程

研究混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响,对传统电火花加工、混粉电火花加工及混粉超声振动电火花加工后Ti-6Al-4V试件的表面粗糙度、表面残余应力和显微硬度进行了测量,采用SEM对3种加工方法的加工试件表面重熔层及微裂纹进行了观察,采用能谱分析仪对加工表面进行了能谱分析,探讨了Al粉、SiC磨料超声振动对电火花加工表面结构和力学性能的影响机理.结果表明:在混粉电火花加工基础上,工作液中加入20g/L的SiC颗粒,电极施加轴向超声振动,可使电火花加工表面粗糙度值Ra降低0.5 μm、重熔层厚度减薄40 μm、表面残余应力降低50 MPa、表面显微硬度由7650 MPa提高到9870 MPa.

关键词: 钛合金 , 超声振动 , 表面结构 , 残余应力 , 显微硬度

水热法制备杂化型CeO2/WC复合材料的电化学性能及表面结构

张红艳 , 黄惠 , 郭忠诚 , 赖耀斌 , 付仁春

材料科学与工程学报

在363 K的温度下,以WC为载体六水合硝酸亚铈为原料,水热法制备不同CeO2含量(0～100 wt％)的CeO2/WC复合材料.以150 g/LH2 SO4水溶液电解为目标反应,考察CeO2含量对CeO2/WC复合材料的电化学性能影响.研究结果表明,CeO2/WC复合材料较纯CeO2和WC有好的电化学活性,且当CeO2的含量为65 wt％时,复合材料的电化学活性和导电性最好.并采用扫描电子显微镜(SEM)、X射线粉末衍射(XRD)和X射线光电子能谱(XPS)对65 wt％ CeO2/WC复合材料的物相、表面结构及WC与CeO2之间相互作用进行分析表征.结果表明,复合材料中CeO2和WC的晶体结构不变,但是复合材料中出现新相,说明它们之间不是简单的物理混合,而是形成新的Ce-O-W键.

关键词: 碳化钨 , 二氧化铈 , 复合材料 , 电化学性能 , 表面结构

改造对沸石基复合环境材料表面结构的影响及应用

董颖博 , 林海 , 霍汉鑫

功能材料

以天然斜发沸石为研究对象,采用不同改造方法对其进行改造,研究发现LaCl3化学改造2h,500℃高温下焙烧1h后所得沸石基复合环境材料去除污水中磷的性能有了较大提高。SEM和EDS测试材料的结果表明,天然沸石改造后其表面形貌发生了改变,孔结构得到了扩展,改造前后材料主要成分均为Si、Al、O,但改造后材料中La离子含量明显增加。材料表面结构测试分析发现,改造后复合材料孔道得到拓宽,孔径分布更为均匀,孔容积、比表面积、孔径数量和孔隙率与沸石原材料相比均有所增加。在此基础上,研究了沸石基复合环境材料用量、处理时间及废水pH值对材料除磷效果的影响,结果表明,材料在用量1.2g/L、处理时间3h、pH值3～7的条件下,对废水中磷去除率可达98.46%。

关键词: 天然沸石 , 复合环境材料 , 表面结构 , 颗粒改造 , 吸附除磷