Y.D. Yu
,
K.F. Zhang
,
H.R. Zheng
,
D.M. Jiang
金属学报(英文版)
Numerical simulation and experimental studies on cavity growth were carried out during the bulging process of superplastic magnesium Alloy. A three-dimensional rigid-
viscoplastic finite element program has been developed and applied to predict the cavity radiusand volume fraction of cavity growth. The final prediction on the cavity
radius and volume fraction distribution was exhibited as colorful shade pictures. The
experimental studies wereperformed under similar conditions to the numerical one
and provided for quantitativecomparison. According to the metallography observation,
the radius and volume fraction of cavity growth was quantitative achieved by using
Profound-Iron & steel software. The numerical results were in reasonable quantitative agreement with the experiment.
关键词:
magnesium alloy
,
null
,
null
,
null
俞善庆
,
张小平
,
马敏伟
材料研究学报
透明薄膜是一种光谱选择性材料,探明该膜系的光谱选择度,对于开发新型能源材料具有重要意义。作者研究了在Al 和Ag 基膜上分别沉积SiO,SnO_2,CeO_2,ZnS 和CdS 介质膜,组成D/M 非对称膜系,测定了它们在320—1000nm 波长范围内的光谱透过率。证明各种介质膜对于金属基膜光谱选择度的影响基本相似,但对于透过率峰值的影响却明显不同;一般说来,介质膜对于Ag 膜的光谱透过率会产生较大的增益,而且介质膜愈厚,增透性愈好。实验结果表明,采用D/M 非对称膜系,有可能研制出光谱选择度满意的透明热反射镜材料。
关键词:
光谱透光性
,
transparent heat-mirror films
,
unsym-metrical optical systems
孙瑶
,
汪洪
航空材料学报
doi:10.11868/j.issn.1005-5053.2015.4.005
采用射频反应溅射制备SiNx薄膜,作为以Ag膜为功能层的D/M/D结构透明导电膜中的电介质膜,并研究射频功率、气压以及N2流量对SiNx薄膜光学常数的影响.结果表明,SiNx薄膜具有非晶态结构,光学常数在300～ 2500nm波长范围内符合正常色散关系.椭偏测试及Cauchy模型拟合结果表明,折射率随功率、气压以及N2流量升高而降低,SiNx光学常数最佳的工艺条件为功率300W,气压0.16Pa,N2与Ar流量比例1∶1,此时薄膜折射率为2.02,消光系数为0,最接近具有化学计量比的Si3N4薄膜的光学常数.按此工艺制备的SiNx膜在优化厚度为44nm的条件下作为20nm厚度Ag膜的电介质膜,当只有表面SiNx膜时,Ag膜透光率由29.17％提高至55.01％,当Ag膜上下均制备SiNx膜时,透光率进一步提高至66.12％.
关键词:
SiNx膜
,
Ag膜
,
折射率
,
椭偏仪
,
透光率
Yong LIU
,
Baiyun HUANG
,
Kechao ZHOU
,
Hongwu OUYANG
,
Yuehui HE
材料科学技术（英）
In order to overcome the shortcomings of conventional hot pressing, a novel near net-shape technique, called radial hot pressing, for P/M parts with large height-to-diameter (H/D) ratio was introduced. Effects of processing parameters on the microstructures and density of P/M TiAl base alloy valves were studied. Results show that the radial hot pressing is an effective technique for manufacturing valves with a H/D ratio of about 10:1, and the perfect joint interface between the Mo sheet and the parts is helpful for subsequent HIPing.
关键词:
Near net-shape technique
,
null
,
null
赵德文
,
郭长武
,
刘相华
,
王国栋
,
徐辉
,
戴建明
钢铁
开展了在空气和氮气两种气氛下，采用Gleeble-1500热模拟机与普通电炉两种加热方式、不同加热温度、加热时间对D2、M2、S5钢脱碳层深度影响的试验研究。依据试验结果，结合现场实际制定了较为合理的生产工艺并在现场成功应用，使上述模具扁钢脱碳层指标达到了美国ASTM-A681技术标准。
关键词:
脱碳层深度
,
模具扁钢
,
ASTM-A681
楼永通
,
宋伟华
,
罗菊芬
,
吕海峰
,
王寿根
,
徐荣安
,
贺持缓
,
李国良
,
陶维正
膜科学与技术
doi:10.3969/j.issn.1007-8924.2004.05.010
在中试基础上建立1200 m3/d电镀镍漂洗水膜法回收工程,采用三级膜分离技术浓缩电镀废水并回收水和镍.一级处理量50 m3/h,浓缩10倍;二级处理量5 m3/h,浓缩5倍;三级处理量1m3/h,浓缩2倍以上,共浓缩100倍以上.一级膜分离系统对镍的截留率为98%;二级、三级膜分离系统对镍截留率均在99%以上.从2001年1月至2002年12月,共运行了2年.三级膜分离系统的通量均有不同程度的下降,一级下降约20%,二级下降约25%,三级下降约40%.整个系统运行良好,基本上实现了电镀废水的资源化.
关键词:
电镀废水
,
膜分离技术
,
截留率
,
通量
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
Physical Review B
In the investigation of the optical and magnetic properties of the semiconductors containing transition-metal ions, the one-electron orbital cannot be treated with a pure d orbital because of a strong covalence. This paper presents the energy matrix of the d*(8) and d*(2) (d* means a modified d function) system, in which the covalence is described by two covalent factors. The differences between the matrix diagonal elements of the t(2)(m)e(n) term of the d*(8) system and the t(2)(6-m)e(4-n) term of the d*(2) system vary with m and n. The d(N) electron system can be explained with the d(10-N) hole system because the difference between the energy matrix of the d(N) and d(10-N) systems has a fixed value. However, this kind of simple relation does not exist for the d*(N) and d*(10-N) systems when the covalence is considered. A numerical calculation shows that the variation of the energy levels with the covalence for Ni2+ in the d*(8) electron system is larger than that in the d*(2) hole system. The calculated energy levels obtained from the d*(8) matrix are in good agreement with the experimental data of the Ni2+ ion for ZnS:Ni and ZnSe:Ni. This suggests that the d*(8) electron system instead of the d*(2) hole system should be used in the investigation of optical and magnetic properties of semiconductor containing Ni2+ ions.
关键词:
zns-ni;absorption;vanadium;impurities;spectra;ions
