X.G
,
Yang
,
Q.A. Zhang
,
K. Y Shu
,
YL. Du
,
YQ. Lei and Q.D. Wang (Department of Materials Science and Engineering
,
Zhejiang University
,
Hangzhou 310027
,
China )W.K. Zhang(Department of Applied Chemistry
,
Zhejiang University of Technology
,
Hangzhou 3100l4
,
China )G.L. Lu(Central Lab
,
Zhejiang University
,
Hangzhou 310028
,
China)
金属学报(英文版)
The annealing treatment was found to improve the cyclic stability but to degmde discharpe capacity, activation and high-rate discharpeability for the Ti-substituted AB2type alloy electrode. A larper polarization was found in the annealed alloy because of its poor discharpe kinetics resulted hem the structural homogeneity. At larae discharpe cumnts, the hydmpen dchsion in the bulk of the alloy was mpaofed as the mte-determining step. Based on the P ressure-composition isotherm measurement, we concluded that the decrease in discharpeability of the annealed alloy is owing to the low and flat pressure plateau, as well as the large hysteresis, but the hydrgen stomge density almost remains unchangeable after annealing.
关键词:
AB_2
,
null
,
null
,
null
,
null
,
null
于萍
,
王亚权
腐蚀科学与防护技术
研究了添加0.1mass%稀土Y的铸造K38G高温合金在1000℃的恒温氧化行为.结果表明,较之不含Y的合金，含Y铸态K38G合金的氧化速率显著降低； 氧化时形成双层的外氧化膜，表层为以Cr2O3和TiO.2为主的混合氧化物层，内层为连续的Al2O3层；没有内氧化和内氮化，没有氧化膜的剥落，加入稀土Y有效地提高了氧化膜的粘附性能.
关键词:
高温氧化
,
null
,
null
,
null
于萍
,
王亚权
腐蚀科学与防护技术
doi:10.3969/j.issn.1002-6495.2007.03.010
研究了添加0.1 mass%稀土Y的铸造K38G高温合金在1000℃的恒温氧化行为.结果表明,较之不含Y的合金,含Y铸态K38G合金的氧化速率显著降低;氧化时形成双层的外氧化膜,表层为以Cr2O3和TiO2为主的混合氧化物层,内层为连续的Al2O3层;没有内氧化和内氮化,没有氧化膜的剥落,加入稀土Y有效地提高了氧化膜的粘附性能.
关键词:
高温氧化
,
K38G
,
高温合金
,
稀土元素
,
Y
于萍
,
王亚权
,
王文
腐蚀科学与防护技术
对加入0.05mass%～0.5mass%稀土Y铸造的K38G高温合金800 ℃恒温的氧化行为进行了研究.结果表明,含Y铸态K38G合金的氧化动力学曲线偏离了抛物线规律，接近于立方规律；Y有效抑制了该合金的内氧化；当Y含量达0.5mass%时，该合金中析出富Y相，降低了其氧化抗力.
关键词:
高温氧化
,
null
,
null
金玉花
,
韩萍花
,
李常锋
,
寇生中
材料工程
doi:10.11868/j.issn.1001-4381.2016.03.008
采用高真空电弧熔炼炉熔炼,制备了K418镍基高温合金.借助SEM对合金的组织进行观察,用EDS对合金中的相成分进行分析,研究了稀土元素Y,Ce对合金中气孔缺陷、γ'相以及(γ+γ')共晶相等的影响.结果表明:添加稀土元素明显减少了合金中的气孔缺陷,提高了合金的致密度,细化了合金枝晶组织.组织中碳化物的形态由大块状变为链状和小块状,γ'相尺寸变小且颗粒数目增多.Y元素的加入能使合金中的(γ+γ')共晶相数目增加.但同时加入Y,Ce两种稀土元素后共晶相数目的增加更为显著.
关键词:
K418合金
,
稀土元素
,
γ'相
,
共晶相
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
沈雅明
,
刘正堂
,
冯丽萍
,
刘璐
,
许冰
稀有金属材料与工程
采用射频磁控溅射法制备HfSi_xO_y薄膜,系统研究工艺参数对HfSi_xO_y薄膜沉积速率的影响规律.对沉积态和退火HfO_2和HfSi_xO_y薄膜的结构进行了对比分析.结果表明:HfSi_xO_y薄膜的沉积速率随射频功率、Ar气体流量和粘贴Si面积的增大而增大,随溅射气压的增大而减小.衬底未加热时,制备的HfSi_xO_y和HfO_2薄膜均呈非晶态,随着衬底加热温度的上升,HfO_2薄膜呈多晶态,而HfSi_xO_y薄膜呈非晶态.HfSi_xO_y薄膜在800℃退火后仍呈非晶态,而HfO_2薄膜在400℃退火后已明显晶化,这表明HfSi_xO_y薄膜具有较高的热稳定性.
关键词:
高K栅介质
,
HfSi_xO_y薄膜
,
射频磁控反应溅射
,
沉积速率
Journal of the American Ceramic Society
Combining Clarke's model with first-principles calculation of average sound velocity, the minimum lattice thermal conductivities (kappa(min)) of Y3Al5O12 (YAG), YAlO3 (YAP) and Y4Al2O9 (YAM) are predicted to be 1.59, 1.61, and 1.10 W.(m.K)(-1), respectively. The weak Y-O polyhedra provide "weak zones" that scattering phonons and lead to the low kappa(min) of ternary Y-Al-O compounds. In addition, the extremely low kappa(min) of YAM is attributed to its higher levels of local disorder of crystal structure and weaker chemical bonding compared with those of YAG and YAP. Inspired by theoretical predictions, dense and phase-pure YAM is synthesized and the experimental thermal conductivity is only 1.56 W.(m.K)(-1) at 1273 K. Finally, YAM is highlighted as a potential thermal barrier material for its low thermal conductivities at temperatures from 473 to 1273 K.
关键词:
barrier coatings;single-crystal;gas;stability
