Z.L. Zhan
,
*
,
Y.D. He
,
W. Gao
金属学报(英文版)
Nanocrystal ODS (oxide dispersion strengthening) aluminide coatings were produced on a stainless steel and nickel-based superalloy by the pack aluminizing process assisted by ball peening. Pure Al powders and 1% of ultra-fine Y2O3 powders were mixed by ball milling. The ultra-fine Y2O3 powders were dispersed in Al particles. Ball peening welded the Al particles onto the substrate and accelerated the formation of aluminide coating. Nanocrystal ODS aluminide coatings were produced by the outward growth at a much low temperature (below 600℃) in a short treatment time. The effects of the operation temperature and treatment time on the formation of the coatings were analyzed. SEM (scanning electron microscope), AFM (atomic force microscope), EDS (energy dispersive X-ray spectroscopy), XRF (X-ray fluorescence spectrometer) and XRD (X-ray diffraction) methods were applied to investigate the microstructure of the coatings. High-temperature oxidation tests were carried out to evaluate the oxidation resistance of the ODS aluminide coatings.
关键词:
nano-coating
,
微米/纳米晶涂层
,
球击处理过
董艳春
,
阎殿然
,
张建新
,
杨勇
,
何继宁
,
陈学广
稀有金属材料与工程
为了提高反应等离子喷涂纳米TiN涂层的致密性、消除涂层内的微观缺陷,在大气、氩气氛和真空中对其进行了热处理.用XRD、SEM、TEM分析了纳米TiN涂层热处理后相组成及组织结构的变化,测试了处理后涂层的结合强度和孔隙率.结果表明:纳米TiN涂层在大气和氩气氛中,于600℃开始发生分解和氧化；真空环境下加热,涂层相组成不发生变化.在大气中600℃加热处理后,TiN涂层中微裂纹愈合,孔隙率降到原来的70％,结合强度基本不变.大气中1000℃热处理后,晶粒尺寸仍为100～200 nm.
关键词:
热处理
,
TiN
,
纳米涂层
,
显微组织
刁彦华
,
王瑞
,
刘岩
,
赵耀华
,
郭磊
,
汪顺
工程热物理学报
本研究以微槽道结构蒸发器为研究对象,以TiO2/R141b纳米流体为工作介质,在不同运行压力条件、不同纳米流体体积分数下对蒸发器的传热特性进行了实验研究.运行压力为0.86×105 Pa、1.0×105 Pa,纳米颗粒的体积分数范围为0.001％～0.1％.运行压力为0.86× 105 Pa时,体积分数为0.001％、0.01％纳米流体会具有明显的强化换热的效果;体积分数为0.1％的纳米流体在高热流密度时出现传热恶化的状况.在运行压力为1.0×105 Pa时,体积分数为0.001％、0.01％的强化效果不明显,而体积分数为0.1％的纳米流体随着压力的增加,传热恶化程度加剧.本研究还对纯工质在微槽道结构表面纳米颗粒沉积层的蒸发/沸腾传热特性进行了实验研究,实验结果表明;纳米粒子沉积层的存在对纳米流体在微槽道结构内蒸发/传热特性具有重要的影响.
关键词:
蒸发/沸腾换热
,
纳米流体
,
微槽道
,
强化换热
,
纳米沉积层
杨建桥
,
霍苗
材料导报
介绍了热喷涂制备纳米涂层的方法,主要是间接喷涂法和直接喷涂法.并简要介绍了国内外研究动态和水平,分析了热喷涂制备纳米涂层所面临的一些难题及现有的解决方法和措施,展望了热喷涂技术在未来制备纳米涂层方面的发展.
关键词:
热喷涂
,
纳米涂层
,
研究进展
