材料期刊网

镁合金化学镀镍预处理过程表面状况的研究

胡文彬 , 向阳辉 , 刘新宽

中国腐蚀与防护学报

采用重量损失、扫描电镜和X射线光电子能谱等方法对镁合 金化学镀镍预处理的表面状况进行了研究.结果表明，镁合金在碱性除油和活化阶段由于表 面上Mg(OH)2和MgF2膜层的形成，受到的腐蚀很小.不同配方的酸性浸蚀溶液导致不同 的腐蚀程度和表面形貌，浸蚀后表面形成的含CrOOH的膜层在活化后消失.

关键词: 化学镀镍 , magnesium alloy , pretreatmen t , surface

冲击球压法研究混凝土表面的腐蚀损伤

岳汉威 , 马振珠 , 包亦望

中国腐蚀与防护学报

pH=2.54, 5 mass%的硫酸铵溶液作为腐蚀介质，以干湿循环为条件，利用冲击球压法研究了混凝土冲击荷载-压痕尺寸、冲击应力-应变关系；对与冲击球压试验相关的其他物理量如抗压强度比、损伤区扩展、试件质量变化及溶液pH值变化等也进行了研究。研究发现冲击球压试验得到的混凝土冲击荷载-压痕尺寸关系曲...

关键词: 混凝土 , surface , erosion , wetting-drying cycle , sphere impact

黄铜矿表面生物氧化膜的形成过程

杨洪英潘颢丹佟琳琳刘媛媛

金属学报 doi:10.3724/SP.J.1037.2012.00279

在细菌浸出黄铜矿的过程中, 浸出速率缓慢的原因是矿物表面会形成一层阻碍矿物与浸出液之间物质交换的钝化膜, 这层膜的组成会随着浸出的进行而变化. 利用SEM, EDS, XRD和XPS等对细菌浸出黄铜矿的过程中, 矿物表面的形貌、组成及物相变化进行了研究. 结果表明, 黄铜矿在细菌浸出过程中依次形成了...

关键词: 黄铜矿 , passivation , surface , bacterial oxidation , jarosite

熔融Cu55团簇在冷却过程中结构变化的分子动力学模拟

张林 , 徐送宁 , 张彩碚 , 祁阳

金属学报

应用分子动力学研究了一个熔融Cu55团簇冷却过程中变为二十面体的结构变化. 根据原子密度分布函数和对分布函数随温度变化的分析表明, 在降温过程中由于原子之间连续地交换位置, 团簇结构发生了三个阶 段的变化: 首先形成三壳层结构, 继之初步形成四壳层结构, 并在团簇内部开始形成由13个原子组成的二十面...

关键词: Cu55团簇 , molecular dynamics , computer simulation , surface

Microstructure of laser remelted Ni-base alloy coating on stainless steel

材料科学技术（英文）

A 5 kW CW CO2 gas laser was used to produce NiCrBSi superalloy coatings. Powders were preplaced by plasma-spraying. The microstructure and chemical composition of the coating have been studied by SEM, XRD and HREM. The results show the coating microstructure is fine dendrites, composed of gamma matr...

关键词: surface

2-DIMENSIONAL FINITE-ELEMENT METHOD SIMULATION OF VICKERS INDENTATION OF HARDNESS MEASUREMENTS ON TIN-COATED STEEL

Thin Solid Films

The finite element simulation uses an indenting wedge (apex angle, 136-degrees) as a two-dimensional approximation of the actual Vickers pyramid. The model assumes isotropic properties for the layer and substrate materials and an elastoplastic behaviour with a work-hardening characteristic. The stre...

关键词: surface

钝化颗粒镁的表面层成分及结构分析

黄均麟 , 万见峰 , 谢超英

物理测试

通过在钝化液中加入一种稀土氧化物制备成一种钝化镁粒，用SEM、XRD、AES分析了这种自制钝化镁粒表面层的成分和结构，发现其表面包覆均匀，致密，XRD和AES结果显示表面层主要含有CeO2和MgO。通过线扫描分析元素浓度沿包覆层方向的变化，大致估算了包覆层的厚度为7~8 μm。经测试其在1〖KG-...

关键词: 钝化镁粒 , combustioninhibiting , surface

NON-EQUILIBRIUM SEGREGATION OF Si ON Al-0.35 wt-% Si ALLOY SURFACE

CHEN Niug , YU Zongsen University of Science and Technology Beijing , Beijing , China professor , Department of Materials Physics , University of Science and Technology Beijing , Beijing 100083 , China

金属学报(英文版)

Si segregation was observed in the vacancy condensation pits,formed by supersaturated vacancies beneath the oxidation layer of Al-0.35wt-%Si alloy,by optical microscopy,X- ray photoelectron spectroscopy and microhardness tests.This phenomenon could only be explained by vacancy-Si complex inducing no...

关键词: non-equilibrium segregation , null , null , null , null

Alkali-metal Na Adsorption and Promoted Oxidation on Si(100)2×1 Surface

Shihong XU Pengshou XU Mingrong JI Xianming LIU Maosheng MA Jingsheng ZHU Yuheng ZHANG Structure Research Laboratory , University of Science and Technology of China , Hefei , 230026 , ChinaZhenjia XU Institute of Semiconductor , Academia Sinica , Beijing , 100083 , China

材料科学技术（英文）

The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemission electron spectroscopy.The experimental data showed that there was a new state,interfac...

关键词: adsorption , null , null , null

OBSERVATION ON DEFECTS IN POLYCRYSTALLINE SILICON THIN FILMS

Y.F.Hu

金属学报(英文版)

Polycrystalline silicon thin films were prepared by RTCVD (rapid thermal chemical vapor deposition) method on several substrates such as SSP (silicon sheet from powder) ribbon, poly-Si wafer and mono-Si wafer, lntra-granular defects such as stacking faults, twins and microstructure defects were inve...

关键词: poly-Si thin film , null , null