送粉激光熔覆WC陶瓷层的高温组织与性能

实验研究了Co基自熔合金、Ni基自熔合金+WC、Co基自熔合金+WC激光熔覆层在不同温度下的显微组织和各种化合物的硬度,结果表明三种材料在相同激光熔覆工艺参数下获得的熔覆层的高温显微组织、性能存在很大的差异,Ni基自熔合金+WC在700℃时硬度开始显著降低且显微组织发生很大变化,而Co基自熔合金和Co基自熔合金+WC在700℃时才开始发生变化且变化幅度较小。同时证明WC在加热过程中硬度没有显著降低。实验结果对获得具有抗高温粘着磨损的激光熔覆层有重要的理论和实际意义。     

激光熔覆技术在减速器轴表面再制造中的应用

针对减速器轴表面的磨损失效,为解决检修过程中表面磨损严重难以维修的问题,采用激光熔覆技术对磨损的减速器轴表面进行再制造,研究了激光熔覆对减速器轴表面金相显微组织、硬度、耐磨性、耐腐蚀性的影响。结果表明：磨损的减速器轴经激光熔覆再制造后,表面熔覆层组织细小致密,熔覆层性能明显提升,耐磨性、耐蚀性分别约为减速器轴基材的2.5倍、2倍,激光熔覆技术在减速器轴再制造中具有广阔的应用前景。     

多道搭接钛合金激光熔覆层组织与耐磨性研究

在钛合金表面进行了激光搭结熔覆WC-12Co涂层的试验,结果表明激光熔覆区在微观结构上分为熔覆层、熔化区和热影响区.在搭接熔覆层出现了较为粗大的组织特征,主要是固溶多种元素的Ti基固溶体;熔化区是熔覆材料与基体钛合金的混熔区,为大小不等的颗粒晶.激光熔覆层的耐磨性比时效处理的钛合金显著提高,磨损机制是剥层磨损和磨粒磨损.     

激光熔覆技术在轧机牌坊修复中的应用

轧机牌坊长期在酸性水、油氛围下使用后窗口和凹槽面均出现了较严重的磨损、腐蚀问题,影响钢材的质量使钢材成品率降低。文章采用堆积焊接与机加工的方式对轧机牌坊各工作面进行预处理,再选择以C-Cr-Ni-W-Fe复合材料在双面胶上设置金属粉末预制层,双面胶的另一面附于工作面上,对金属粉末预制层进行激光熔覆,最后对熔覆层打磨、抛光达到对轧机牌坊的修复目的。对最终的熔覆层进行现场性能检测,其熔覆层厚度、焊后硬度、粗糙度、水平度均达到标准值,轧机修复效果良好。     

激光熔覆钴基合金组织及其抗腐蚀性能

采用CO2 激光在 2Cr13不锈钢表面熔覆Co基合金 ,对熔覆层的组织结构及腐蚀性能进行了研究。结果表明 ,选择合适的激光辐照工艺参数 ,可获得性能优异的Co基合金熔覆层。熔覆层的组织为极其细密的枝晶组织 ,由于熔覆层富含Co ,Cr等合金元素 ,因而与 2Cr13不锈钢相比 ,同一电位下Co基合金在 2 3℃ 3 5 %NaCl盐溶液中腐蚀电流密度减小一个数量级。PbSO4盐热腐蚀试验结果表明 ,大量的Co ,Cr促进了CoO ,CoO·Cr2 O3致密保护膜的形成 ,因而熔覆层表现出优异的高温腐蚀性能。     

飞机起落架轴颈模拟试样的激光熔覆

采用三种不同的合金粉末对制造飞机起落架的常用材料30CrMnSiNi2A进行了激光熔覆处理。并与对磨的高频淬火试样进行了环与环的接触疲劳磨损试验,用失重法比较了三种粉末激光熔覆后的耐磨性。并且对其中Ni基试样的熔覆层及过渡层进行了硬度分析、金相组织及性能分析。结果表明:采用激光熔覆工艺能显着提高试样的耐磨性,其中又以含有30%WC的Ni基粉末为最好。     

曲轴轴颈损伤表面的激光熔覆再制造修复

为了实现发动机曲轴的激光熔覆再制造修复,采用激光熔覆技术在曲轴材料45#钢样板表面制备铁基激光熔覆层,研究了熔覆层的性能,利用光学显微镜和显微硬度计进行了熔覆层金相组织观察和硬度测试。试验结果表明,熔覆层与基体结合良好,且熔覆层硬度为基体硬度的2~3倍;为了使曲轴在绕主轴颈旋转情况下对多拐曲轴连杆轴颈进行激光熔覆,提出了在连杆轴颈表面获得连续均匀熔覆层应满足的条件,并在满足这些条件的前提下,推导出了激光熔覆曲轴连杆轴颈过程中激光束与转动轴颈的运动轨迹和相对速度之间的关系模型,通过试验,验证了轨迹模型的可行性。     

AA7075铝合金表面激光熔覆Zr基复合涂层的组织与磨损行为

为了提高铝合金的磨损性能,采用激光熔覆技术在AA7075铝合金表面熔覆了Zr-Cu-Ni-Al-TiC复合粉末,制备出Zr基复合涂层。采用SEM和XRD技术研究了熔覆层的组织；采用干滑动磨损方法评价了涂层的耐磨性。研究结果表明：熔覆层组织主要由非晶和金属间化合物组成。在非晶相和金属间化合物复合作用下,熔覆层表现出优异的耐磨性,尤其是随着熔覆层中TiC含量的增加,耐磨性得到显著的提高。     

高温合金K403的激光熔覆研究

研究了高温合金K403基体上商用镍基自熔合金和自配无硼、硅元素镍基合金的激光同步送粉熔覆过程,分析了基体组织状态、熔覆层材料和熔覆工艺参数对熔覆层裂纹倾向的影响,探讨了激光熔覆技术强化和修复高温合金叶片的可行性。研究发现,激光熔覆时大多数裂纹是从基体侧形成后深入到熔覆层中,而基体组织中缩松等铸造缺陷及晶界低熔点共晶的存在是熔覆层开裂的重要原因。采用无硼、硅元素合金熔覆改善了结合区性能,与自熔合金相比,有助于改善熔覆层裂纹倾向。加入适量稀土氧化物有助于减少或消除裂纹。熔覆工艺参数对裂纹产生的影响较大,存在一个无裂纹参数选择范围。研究证明,高温合金基体上熔覆无硼、硅元素合金更易于消除熔覆层裂纹,实现强化与修复更具优势。     

激光熔覆高温合金及其应用

高温工模具的失效方式主要为工作面的热磨损和氧化热疲劳。针对这一特点，选用镍基高温合金＋ＷＣ和ＭＣｒＡＩＹ合金（Ｍ＝Ｎｉ，Ｃｏ）＋ＷＣ进行激光熔覆试验，并对激光熔覆层进行组织性能测试。结果表明，镍基高温合金＋ＷＣ有较高的热强性，而ＭＣｒＡＩＹ＋ＷＣ则有较佳的抗氧化性。将两类合金激光熔覆层应用于无缝钢管顶头上提高使用寿命１～４倍。其中以ＭＣｒＡＩＹ合金＋１０％ＷＣ激光熔覆顶头寿命最长。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.