材料期刊网

STRAIN RATE SENSITIVTTY OF POLYCRYSTALLINE AND SINGLE CRYSTAL NiAl

HSU Shuen , YANG Sycherng , HON Weipirn , WANG Chienyi LEE Tsangsheau (Chung-Shan Institute of Science and Technology , Lung-Tan , Taiwan , China) HSU Ichung(National Taiwan University , Taipei , Taiwan , China) CHIN Stephen , ANTON Donald L.(United Technologies Research Center , East Hartford. CT , USA)

金属学报(英文版)

The compressive and tensile strain rate sensitivities of polycrystalline and single crystal NiAl have been evaluated at 877 ℃ which is well above DBTT. Samples were prepared to specific sizes by hot press consolidation of appropriate powder sizes and minimizing past consolidation thermal exposures. NiAl single crystals were grown in the [100]orientation using a modified Bridgeman technique. The yield and tensile strength of polycrystalline NiAl as a function of grain size generally follows a Hall-Petch type relationship . A tensile strain rate effect was found at strain rate of 1 to 10-4 sec-1. The strain rate sensitivity coefficient, m,in the equation of σ = Kε is in the range of 0. 10 to 0. 13. The highest strain rate (1 sec-1) resulted in significantly higher strengths and little or no observed ductility. Compressive strain rate testing al strain rate of 10-5to 10-2 sec-1 and at temperature of 1050°to 1250°K was conducted both for polycrystalline and for single crystal NiAl. The calculated stress exponents and the activation energy for creep were compared with the reference data.

关键词: :strain rate sensitivity polycrystalline NiAl , null

立方 TaN纳米粉的制备

类伟巍 , 沈龙海 , 刘丹 , 李雪飞 , 彭刚 , 崔启良 , 邹广田

无机材料学报 doi:10.3724/SP.J.1077.2007.00400

采用直流电弧法使金属钽和氮气直接反应制备出了TaN纳米粉．利用XRD、XPS、TEM等测试方法对所制备的TaN纳米粉进行了表征．结果表明: 所制备的纳米粉为单一的立方相TaN, 纳米颗粒的平均粒度为5~10nm．实验中还发现氮气的气压对制备纯立方相TaN具有关键性作用, 并讨论了立方相TaN的形成机理．

关键词: 立方相TaN , nanocrystallites , dc arc discharge method

立方TaN纳米粉的制备

类伟巍 , 沈龙海 , 刘丹 , 李雪飞 , 彭刚 , 崔启良 , 邹广田

无机材料学报 doi:10.3321/j.issn:1000-324X.2007.03.004

采用直流电弧法使金属钽和氮气直接反应制备出了TaN纳米粉.利用XRD、XPS、TEM等测试方法对所制备的TaN纳米粉进行了表征.结果表明:所制备的纳米粉为单一的立方相TaN,纳米颗粒的平均粒度为5～10nm.实验中还发现氮气的气压对制备纯立方相TaN具有关键性作用,并讨论了立方相TaN的形成机理.

关键词: 立方相TaN , 纳米粉 , 直流电弧法

Microstructural study on multilayer FeTaN/TaN (5) films

Materials Letters

The microstructure of [FeTaN/TaN](5) multilayer films has been investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM) in cross section and plan view. Each layer shows a small surface roughening less than 1 nm. The FeTaN layers are composed of b.c.c. Fe with Ta incorporated substitutionally and N interstitially, denoted as Fe(Ta,N); while the TaN layers mainly consist of f.c.c. TaN phase. A [110] texture of Fe(Ta,N) has been formed in the FeTaN layers. The columnar grain structure is a typical feature in FeTaN layers. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词: microstructure;thin films;magnetic materials;transmission electron;microscopy (TEM);sputtering;fetan thin-films;magnetic-properties;recording-heads;tantalum;nitride;temperature

High temperature naphthenic acid corrosion of steel in high TAN refining media

Anti-Corrosion Methods and Materials

Purpose - This paper aims to study the corrosion behavior of carbon steel and stainless steel in white oil with naphthenic acid under high temperature. Design/methodology/approach - The weight-loss method and surface analysis were used to study the corrosion behavior of steel in white oil with naphthenic acid. Findings - Naphthenic acids corrosion rates were directly related to experimental temperature, immersion time and total acid number (TAN). The activation energy was calculated and the process kinetics could be represented by Arrhenius-type equation. The relationship between the isothermal line in liquid phase and that in vapor phase at different TAN values had a significant distinction with the change of temperature. Originality/value - The findings have important implications for assessing the corrosivity of crude oils with high TAN value from various resources.

关键词: Corrosion;Stainless steel;Oils;Acids;refineries

TaN薄膜局部腐蚀早期过程的ECAFM原位研究

俞春福 , 徐久军 , 黑祖昆

腐蚀与防护 doi:10.3969/j.issn.1005-748X.2004.03.005

电化学原子力显微镜(ECAFM)可以在液体环境下工作,能原位观察电极反应过程中的腐蚀界面形貌.文章介绍利用ECAFM从纳米空间分辨度上原位研究离子束增强沉积TaN膜在0.4mol/L HCl溶液中的局部腐蚀早期过程,结果发现,表面形貌为颗粒状结构的TaN膜在0.4mol/L HCl中进行阳极极化时,颗粒结构的微观顶峰优先溶解,导致颗粒高度降低,边界扩大蔓延,使膜层表面趋于平整化.

关键词: 电化学原子力显微镜 , TaN , 原位 , 腐蚀

不同调制周期Cu/TaN多层膜的微结构与表面形貌

赵海阔 , 雒向东

量子电子学报 doi:10.3969/j.issn.1007-5461.2009.01.018

采用磁控溅射方法在Si(111)基底上沉积不同调制周期的Cu/TaN多层膜,用X射线衍射仪(XRD)与原子力显微镜(AFM)表征薄膜微结构与表面形貌,研究了不同调制周期L薄膜的微结构与表面形貌.结果表明:不同L的TaN调制层均为非晶结构,多晶Cu调制层的晶粒取向组成随着L改变而变化; Cu调制层的表面粗糙度Rrms.大于TaN调制层的Rrms;与Cu单层膜相比,最外层为Cu调制层的Cu/TaN多层膜的Rrms较小;与TaN单层膜相比,最外层为TaN调制层的Cu/TaN多层膜的/Rrms较大;随着L增加,多层膜与对应的单层膜之间的兄Rrms差值逐渐减小.

关键词: 光电子学 , Cu/TaN , 多层膜 , 调制周期 , 表面形貌

沉积法制备TaN薄膜的研究现状及其应用

高亮 , 杨建广 , 陈胜龙 , 杨济豪 , 吴玉山

材料导报

TaN薄膜是一种重要的高新技术材料,主要介绍了物理气相沉积法(PVD)、金属有机化学气相沉积法(MOCVD)和原子层沉积法(ALD)制备TaN薄膜的工艺技术,评述了它们各自的优缺点.从前驱体的选择方面详细评述了MOCVD法和ALD法制备TaN薄膜的研究进展,比较和评述了各类前驱体的优缺点.总结了TaN薄膜的应用现状以及薄膜制备过程中的主要影响因素,并简要展望了其发展方向.

关键词: PVD , MOCVD , ALD , TaN薄膜 , 前驱体

热处理对TaN薄膜微结构及电性能的影响

蒋洪川 , 向阳 , 王超杰 , 莫绍毅 , 雷云 , 张万里

材料导报

采用直流磁控溅射制备TaN薄膜,研究了热处理对TaN薄膜微结构及电性能的影响.结果表明,退火温度及退火时间都将影响薄膜的微结构及方阻.随退火温度的升高和时间的延长,TaN薄膜的方阻逐渐增大,但当退火温度高于800℃时,由于氧化严重导致薄膜的方阻异常增大.退火可显著改善薄膜的TCR,制备态TaN薄膜的TCR值为-1.2X10-3,薄膜经800℃退火30min后,其TCR可降低到-7.0x10-4.

关键词: TaN薄膜 , 退火 , 微结构 , 方阻

NbN/TaN纳米多层膜的微结构及超高硬度效应

许俊华 , 李戈扬 , 顾明元

无机材料学报 doi:10.3321/j.issn:1000-324X.2000.03.033

用磁控反应溅射的方法在不锈钢基片上制备了NbN/TaN纳米多层薄膜,试验采用X射线衍射仪(XRD)、透射电子显微镜(TEM)及显微硬度仪对薄膜的微结构和硬度进行分析,结果表明:在NbN/TaN多层膜中,NbN层为面心晶体结构,TaN层为六方晶体结构;NbN/TaN纳米多层膜存在超硬效应,在调制周期2.317.0nm这一较宽的范围内保持超高硬度,硬度最大值HK达51.0GPa.

关键词: NbN/TaN纳米多层膜 , 微结构 , 超硬效应