容敏智
,
章明秋
,
梁海春
,
曾汉民
材料研究学报
采用微乳液法结合原位表面修饰合成了纳米尺度的硫化镉粒子, 采用溶液共混和静态铺膜方法制备了纳米粒子/聚合物复合体系, 以研究纳米粒子与聚合物间的界面作用. 结果表明, 经修饰的纳米CdS粒子比较均匀地分散于聚合物基体内, 纳米粒子与聚合物基体间存在较强的相互作用. 根据复合体系的紫外--可见吸收光谱和荧光光谱, 分析了表面修饰(表面修饰剂种类、表面修饰剂用量等)对纳米粒子的分散以及复合体系界面特性的影响,
证实了表面修饰剂具有促进纳米粒子分散和消除粒子表面缺陷的作用.
关键词:
复合材料
,
interface interaction
,
micro-emulsion
,
nano-meter CdS
,
surface modification
刘桂新
,
金宗哲
,
王廷籍
材料研究学报
本文采用热CVD 方法,在ZrB_2-SiC 复合陶瓷基体上制备CVD·SiC-C 梯度涂层。采用XRD,SEM,及X 射线应力分析方法,研究了CVD·SiC-C 梯度涂层的相组成、显微结构、残余应力及弯曲强度等性能。结果表明,CVD·SiC-C 梯度涂层可以缓解SiC 与ZrB_2基体间的热应力及界面应力,涂层中的残余应力得到明显缓解;高温退火处理对CVD·SiC-C 涂层中的残余应力亦有缓解作用;梯度涂层显著改善了基材的弯曲强度。
关键词:
热化学气相沉积
,
gradient coating
,
residual stress
,
surface modification
檀雨默张爱波郑亚萍兰岚陈伟
材料研究学报
Fe3O4纳米粒子与离子型改性剂N, N-二癸基-N-甲基-N-三甲氧基硅正丙基氯化铵进行接枝反应, 再采用反离子脂肪醇聚氧乙烯醚磺酸盐的长链阴离子交换Cl-, 在Fe3O4纳米粒子表面得到具有阴、阳离子双电层结构的表面处理层, 制备出了无溶剂Fe3O4纳米流体。分析结果表明, 表面处理层已成功地接枝在Fe3O4纳米粒子表面, 改性的Fe3O4纳米粒子呈单分散, 其损耗剪切模量G''明显大于储能剪切模量G', 并具有明显的流体行为, 室温下存放一年状态稳定, 流动性良好。
关键词:
无机非金属材料
,
magnetic nanoparticles
,
surface modification
,
solvent–free nanofluids
,
solid–liquid transformation
张锋刚朱小鹏王明阳雷明凯
金属学报
doi:10.3724/SP.J.1037.2011.00228
利用离子能量为300 keV, 束流密度为300 A/cm2, 功率密度为108 W/cm2, 脉冲宽度为70 ns的强流脉冲离子束(HIPIB)对用于核主泵轴密封的WC-Ni硬质合金材料进行了表面辐照处理, 辐照次数分别为 1, 5, 10次. 利用XRD, SEM和EPMA研究了HIPIB辐照前后WC--Ni硬质合金表层相组成、表面形貌和元素分布的变化, 借助显微硬度计和环--块式磨损仪测试了辐照前后硬质合金表层的性能. 结果表明, HIPIB辐照硬质合金表层发生由六方碳化物WC向fcc碳化物β-WC1-x转变, 转变量随着辐照次数的增加而增加. HIPIB辐照引发硬质合金表层快速重熔和Ni黏结相的择优烧蚀, 形成了许多丘状表面凸起, 且随辐照次数的增加, 丘状凸起的尺寸增大, 当辐照次数增加至10次, 形成了网状“峰--谷”起伏结构的重熔烧蚀表面形貌, 且具有微区光滑致密化特征. 由于HIPIB辐照应力波的显著作用, 辐照后硬质合金表层沿深度方向显著硬化, 10次辐照后硬化层深度可达160 μm, 表面摩擦系数降低38\%, 耐磨性提高近3倍.
关键词:
强流脉冲离子束
,
WC-Ni cemented carbide
,
surface modification
,
wear resistance
王旭
,
张俊善
,
雷明凯
金属学报
利用离子能量为300 keV、束流密度为200 A/cm2、脉冲宽度为75 ns的混合离子束(70%H++30%C+)组成的强流脉冲离子束(HIPIB)对316L不锈钢进行了表面辐照处理, 辐照次数分别为1, 5, 10次. 采用SEM, XRD, TEM和EPMA分析辐照后试样表面形貌、表面层相组成和微观结构及元素分布的变化. 结果表明, HIPIB辐照使试样表面光滑化, 表面层晶粒细化、产生择优取向, 杂质元素选择性烧蚀, 电化学腐蚀性能明显提高. 由于HIPIB辐照引起的大应力和冲击波的影响, 辐照后在深度达100μm表层内显微硬度提高, 表面摩擦系数降低, 表面抗磨损性能显著改善.随着辐照次数的增加, 316L疲劳极限和蠕变断裂寿命延长, 稳态蠕变速率降低.
关键词:
强流脉冲离子束
,
316L stainless steel
,
surface modification
Y.J. Ge
,
G.Q. Zhang
,
Y.M. Liu
金属学报(英文版)
The surface modification of nanometer carbon material has been studied by usingan Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimentalresults show that with different work gases and different discharge conditions, thesurface behaviors of carbon black can be changed according to needs, including theuse of different functional groups and the change of the surface roughness of carbonparticles etc., which increased the grinding and dispersion abilities in binder.
关键词:
surface modification
,
null
,
null
,
null
ZHANG Dawei YU Weicheng WANG Zhongguang National Laboratory for Fatigue and Fracture of Materials
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
金属学报(英文版)
Carbon ions with a dose of 3×10~(17) ions/cm~2 was implanted into Ti-6Al-4V alloy at an energy of 80 keV.A 28% increase in edurance limit was found with implantation under stress-controlled fatigue tests(R=O).The surface microstructure changes induced by ion implantation were identified using transmission electron microscopy(TEM).The feature of the fracture surface were observed on scanning electron microscope(SEM).The distribution profile of the implanted ions was measured by secondary ion mass spectroscopy(SIMS).The implanted surface layers contain a high density of irradiation defects and fine TiC precipitates.Subsurface crack origins were found in specimens either with or without implantation.The implanted species diffuse into matrix metal under the action of cyclic load- ing.A possible reason and mechanism for improving fatigue lifetime are also discussed.
关键词:
surface modification
,
null
,
null
C.X. Shi(National Natural Science Foundation of China
,
Beijing 100083
,
China Manuscript received 26 August 1996)
金属学报(英文版)
A comprehensive survey was made of various candidate high temperature materials for gas turbine use, and their relative merits and drawbacks were assessed. It is shown that superalloys, fine-tuned, will be persistent for the next few decades, to be followed up by high temperature intermetallics. For advanced ceramics, the problems of reliability and cost will have to be solved before they can be used in critical parts of engines.So are C/C composites with their oxidation problem. Surface modification and development of thermal barrier coatings can effectively overcome many problems of gas turbine materials and these technologies should be emphasized.
关键词:
:superalloy
,
null
,
null
,
null
,
null
S.D.Yao
,
C.Sun
,
S.Q.Zhou
,
C.C.Sun
金属学报(英文版)
By implanting B+ and O+ ions respectively into polycarbonate (PC) plates, the sur-face mechanical properties of PC have been improved. Measurement by Nano IndenterⅡ showed that the hardness of samples increased 7-25 times than that before implan-tation; and the modulus of elasticity raised 2-5 times. The wear-resistance was testedby ball crusher; the width and depth of the wear-streak decreased by 1/3-1/2 or evenmore. The structure, deformation and appearance were analyzed by using Micro-FTIR Spectra, ESCA method and the steps instrument. These analyses showed thatthe structure of PC had been modified: a series of new cross-linking yielded, it de-pends on the Linear Energy Transition (LET) of implanted ions in the high polymercompounds.
关键词:
polycarbonate
,
null
,
null
