丁杰
,
张本革
,
闫明珍
,
刘佳
中国腐蚀与防护学报
在化学镀Ni-P/PVDF合金镀液中添加稀土元素Y3+和La3+制备Ni-P/PVDF(RE)复合镀层,用电化学腐蚀测试系统测试复合镀层的耐蚀性,研究了稀土元素的添加量对镀层耐蚀性能的影响。结果表明,在基础镀液中加入适量稀土元素后,所获得的Ni-P/PVDF(RE)复合镀层的晶粒较Ni-P/PVDF镀层更为细小,表面更加均匀和致密;镀层的耐蚀性随着稀土元素加入量的增加呈现先增强后减弱的趋势;在稀土元素的添加量为0.1g/L时,复合镀层的耐蚀性最好。在PVDF微粒和稀土元素的共同影响下,进一步提高Ni-P/PVDF(RE)镀层的耐蚀性。
关键词:
化学镀
,
Ni-P/PVDF coating
,
rare earth
,
corrosion resistance
江静华
,
蒋建清
,
杨长勇
中国腐蚀与防护学报
借助稀土优良的物化特性改善低温熔融渗硫层的抗蚀性。考察了稀土添加剂的类别和加入量对渗层腐蚀行为的影响规律,基于孔蚀理论揭示了微量稀土的作用机理,确定了稀土添加剂的优选方案。研究表明:采用稀土催渗的渗硫试样抗大气和电解液腐蚀性能均明显改善,其在5 wt % NaCl溶液中的稳定电位升高,失重率仅为非稀土催渗试样的1/2左右;改善效果取决于稀土元素及其阴离子种类,其中CeCl3效果最佳,其次为LaF3、La2O3、LaCl3和YF3;综合稀土的催渗效果以及渗层耐蚀性要求,宜采用适量的LaF3(催渗效果最好)与CeCl3共同配制渗硫剂,合适的添加比约为4:1。
关键词:
低温渗硫
,
rare earth
,
anti-corrosive
,
catalyz
Rongjun XIE
,
Tianliang ZHOU
,
Kohei TAKAHAHIS
,
Naoto HIROSAKI
应用化学
doi:10.11944/j.issn.1000-0518.2016.08.160240
GaN-based white light-emitting diode(LED) is now an emerging backlight technology for large color gamut and high efficiency liquid crystal displays. In this technology, phosphors are key materials to control the color-space coverage, luminous efficiency, and lifetime of the backlight units, which are required to have a desired emission and a narrow emission band. β-Sialon:Eu2+(sialon:silicon aluminum oxynitride, Si6-zAlzOzN8-z) is such a green phosphor because it has an emission band centered at 525~545 nm and a small band width(~55 nm). This contribution overviews the synthesis, luminescence, electronic and crystal structure, reliability and applications of β-sialon:Eu2+. From both structure calculations and experimental observations, Eu2+ is seen to be accommodated into a large void along the c-axis, and coordinated to six nitrogen/oxygen atoms at an equivalent distance. The narrow emission band is thus ascribed to the high symmetry of the local structure of Eu2+. Both of the emission band and the band width of β-sialon:Eu2+ can be tuned by tailoring the composition(e.g., the z value), and β-sialon:Eu2+ with shorter wavelengths and narrower bands can be achieved at lower z values. Combined with other red phosphors, β-sialon:Eu2+ enables to produce wider color gamut backlights(15% up) than the conventional yttrium aluminum garnet(YAG)-based ones. Both the excellent luminescence properties and reliability make β-sialon:Eu2+ to be an extremely important green phosphor for use in advanced displays.
关键词:
rare earth
,
nitride
,
beta-sialon:Eu2+
,
phosphor
,
electronic structure
,
light-emitting diode
,
backlighting
赵宇光
,
李道韫
,
王守实
,
何镇明
金属学报
采用电子探针、二次离子质谱、无汞真空套管测氢仪等检测手段,并配合金相分析及试样孔隙度的测定,鉴定出含稀土的Al-Si合金中有稀土氢化物的存在,确认在多元稀土金属间化合物中氢的富集,提出稀土具有较强固氢作用的观点。对加稀土前后Al-Si合金中各形态氢的相对含量变化作了定性分析,对稀土净化Al合金的原因进行了探讨,指出固氢是降低游离氢含量、减少氢致缺陷的重要原因。
关键词:
Al-Si合金
,
rare earth
,
hydrogen
赵高敏
,
王昆林
,
刘家浚
金属学报
通过扫描电镜(SEM)研究了稀土氧化物La2O3对铁基合金激光熔覆层组织形貌的影响,用纳米硬度探针测定了熔覆层与基体界面附近和搭接区的硬度和弹性模量,并用MT--3型显微硬度计测试了多道熔覆层硬度的面分布。结果表明,稀土的加入细化了晶粒,减小了二次枝晶间距;近界面和搭接区的纳米硬度和弹性模量有不同程度的提高。硬度面分布测量结果表明,加入稀土后熔覆层的平均硬度(HV)约为500,比未加稀土的提高约50。本文还讨论了稀土作用的机理。
关键词:
激光熔覆
,
rare earth
,
elastic modulus