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1.
通过比较Al-Zn合金和Al_2O_(3p)/Al-Zn复合材料的激光重熔组织。分析Al_2O_3颗粒对Al-Zn合金激光快凝组织的影响规律。实验结果表明,Al_2O_3颗粒可以显著细化激光熔区的晶粒。基于凝固界面与颗粒交互作用的理论分析,给出了晶粒细化的临界条件。  相似文献   

2.
使用配备EDS的SEM,研究了MmNi5-基储氢合金的微观组织和微区成分。研究的合金中稀土元素含量低于化学比,晶界有Co,Mn和Al富集相析出。分别使用ReB6、ReP5O和纯稀土金属作为分析稀土元素的标样进行定量分析。结果表明,全部采用纯金属标样(包括纯稀土金属标样)分析结果最好;采用ReB6和ReP5O14作为分析稀土的标样时,分析误差较大。文章对误差较大的产生原因进行了讨论。  相似文献   

3.
激光表面快速熔凝过程中熔区组织重构   总被引:8,自引:0,他引:8  
利用晶体生长的最小过冷度判据,对单晶合金激光重熔区组织的生长速度进行了分析,建立了枝晶尖端生长速度与激光束扫描速度和固液界面前进速度的关系.根据此分析对熔池进行了重构和预测,发现激光熔池中枝晶组织的生长方向强烈地受基材晶粒取向和激光束扫描方向的影响.枝晶生长条件下,择优取向对枝晶生长方向的影响要较热流的影响大.理论预测与实验结果相吻合.  相似文献   

4.
钛合金的激光气体氮化研究   总被引:6,自引:1,他引:5  
本研究了Ti-6Al-4V合金的激光气体氮化,试验结果表明在激光功率密度大于5.0×10^4W/cm^2,氮气压力为0.4MPa,通过激光辐射可在Ti-6Al-4V合金表面形成氮化钛。其氮化层的厚度为400μm。在氮化层中存在大量氮化钛枝晶。其平均二次枝晶间距为1.77μm。细小的氮化钛枝晶均匀地分布在氮化层中。最后测定和分析了氮化层的显微组织、相成份和显微硬度,并讨论了氮化钛的形成过程。  相似文献   

5.
类氖离子AlⅣ-XVI2s~2p~54f,5f能级跃迁的理论研究陈宏善,赵仪,董晨钟(西北师范大学物理系,兰州730070)最近,我们用相对论组态相互作用方法详细分析了类氖离子AlⅣ-MnXV2s2p~63l与2s~22p~5nl(n=4,5,6)之间的?..  相似文献   

6.
RuO_2-Ag低阻浆料中掺入MnO_2、V_2O_5杂质改善电阻特性宋兴义(昆明贵金属研究所昆明650221)为了改善RuO2-Ag系低阻浆料的电阻温度系数,大多采用在电阻浆料中掺入表1掺MnO2的RuO2-Ag电阻浆料配方MnO2、V2O5、Nb2O...  相似文献   

7.
采用类金属透明模型合金SCN-Eth合金, 在自主搭建的激光熔池凝固过程宏微观实时观察平台上, 研究了激光重熔过程中熔池宏微观形态演化规律。研究发现, 随着激光束扫描的进行, 熔池及其热影响区的宏观形态都先从圆形变为椭圆形, 最后演化为尾部呈“V”形的泪滴状。随着激光功率的增加, 稳态熔池长度L、宽度W、尾部夹角α均增加; 随着扫描速度的增大, 稳态熔池长度L、宽度W、夹角α均减小; 熔池长宽比随功率的增加而增大, 随扫描速度的增加先增大后减小。从熔池中部到熔池尾部液固界面形貌依次呈平面→胞晶→枝晶演化, 胞晶和枝晶一次间距不同, 浅胞间距约为28 μm, 深胞间距约为42 μm, 枝晶间距约为65 μm, 胞枝晶一次间距沿固液界面增大。  相似文献   

8.
在焊点与铜基之间形成的Cu-Sn合金成分对表面安装器件的疲劳寿命起着关键性的作用。本文着重研究了93.5Sn3.5Ag(简写为Sn-Ag)焊料与Cu基界面间形成的合金层,通过电子扫描显微镜(SEM),X衍射(XDA)及能谱X射线(EDX)等分析发现,在Sn-Ag与Cu基界面上存在Cu6Sn5及Cu3Sn两种合金成分,且随着热处理时间增加,Cu6Sn5合金层增厚,并在该处容易出现裂纹而导致焊点强度减弱,从而使焊点产生疲劳失效。  相似文献   

9.
激光表面熔覆SiCp/Ni-Cr-B-Si-C涂层的组织演化及其相确定   总被引:3,自引:0,他引:3  
运用激光熔覆技术在AISI1045钢表面制备了30vol-%SiCp/Ni-Cr-B-Si-C涂层。SEM和TEM观察分析表明:SiCp在熔覆过程中完全溶解;涂层结合区组织为共晶结构;涂层组织由初生石墨球G,分布在γ-Ni固溶体枝晶中的M23(C,B)6细小网状树枝晶以及少量Ni+Ni3(B,Si)层片状共晶组成;Si在Ni固溶体中的固溶度显著增大,高达14.41wt-%;M23(C,B)6含有高密度堆垛层错;Ni3(B,Si)相具有长周期结构。  相似文献   

10.
ZnO导电陶瓷的制备及其性能表征   总被引:7,自引:0,他引:7  
本文利用化学共沉淀法分别制得Zn5(CO3)2(OH)6掺杂Al(OH)3、Mg(OH)2以及Zn5(CO3)2(OH)6掺杂Sb(OH)3、Bi(OH)3、Sn(OH)4、Co(OH)3、MnO(OH)2两种复合粉体,利用高频等离子体焙解新工艺,制得了纳米ZnO及相应的添加剂陶瓷复合粉体.TEM分析结果表明:两种陶瓷复合粉体的粒径均小于100nm.利用前者,通过添加适当的Al2O3和MgO,制备出了电阻率约10~2000Ω·cm,V-I特性较好的ZnO线性陶瓷电阻.利用后者,通过适当的杂质配比,在100  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

13.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

14.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

17.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

18.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

19.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

20.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

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