钢用硬质覆层材料的显微结构分析

用反应烧结法在A3钢表面制备了三元硼化物基硬质覆层材料YF-1，其硬度可达82～90HRA。用扫描电镜（SEM）、X射线衍射（XRD）和电子探针（EPMA）进行的显微结构研究结果表明：YF-1的表面硬质覆层主要是由三元硼化物基硬质相Mo2FeB2和铁基粘结相a-Fe组成，硬质相分散均匀。在硬质覆层和A3钢的界面存在明显的元素扩散，界面结合良好，界面结合强度高。     

激光熔覆多元复合硬质合金覆层的组织结构

试验研究了多元复合硬质涂层ＣｏｉＣ－ＷＣ－ＴａＣ的激光熔覆,分析结果表明：熔覆层中硬质相及其成分、组织结构分布均匀,硬质相和粘结相及其相互间的润湿性良好,涂层无气孔裂纹缺陷。熔覆层中存在梗质相的溶解、扩散及新相形成。多元复合熔覆层硬度达ＨＣ０．２ １２５０～ＨＶ０．２ １３５０,性能优于单一硬质合金涂层Ｃｏ－ＷＣ、Ｎｉ－ＷＣ。     

45钢表面激光熔覆316L涂层显微组织与性能

采用激光熔覆技术在45钢表面制备316L合金涂层,分析了激光熔覆层的微观组织,测试了激光熔覆层的微观显微硬度。结果表明：激光熔覆区显微组织为细小树枝状结晶组织,熔覆区微观组织均匀致密以及存在着硬质点弥散分布,使得表面耐蚀性、硬度和耐磨性大幅度提高。熔覆层中残余应力一般是拉应力,随着熔覆层厚度的增加,应力回落并逐渐稳定下来,且基体残余应力较熔覆层小。     

50#钢表面激光熔覆不锈钢粉的研究

本文研究了在50^#钢表面激光熔覆KF－120不锈钢粉的工艺，得到了无裂纹、无气孔、组织致密的激光熔覆层。显微组织观察和显微硬度测试表明熔覆层具有很好的耐腐蚀性能和高的硬度。当激光功率为1.6和1.8kW时，熔覆层硬度高达730Hv左右，与基体分界面清晰，而当激光功率为2．0和2．2KW时，硬度分别降为680和650Hv左右，与基体之间无明显的分界面。这两种情况分别适用于不同的应用场合。     

304不锈钢表面激光熔覆铁基复合涂层的组织与性能研究

在304不锈钢表面预置不同质量分数的Fe60和WC复合粉末，采用光纤激光加工系统制备金属-陶瓷复合熔覆层。分别从宏观形貌、微观组织、物相分析、硬度分布等角度研究涂层的组织结构及性能。结果表明：复合熔覆层冶金结合良好，过渡区、热影响区生成CrC及WC_x等硬质相，提高了熔覆层的硬度，对复合涂层力学性能有显著影响；当WC的质量分数比例为3%时，熔覆涂层的平均硬度为995 HV,约为304不锈钢基体的5倍，且高于其他质量分数比例的复合熔覆层。     

基体材料对NiCrBSi激光熔覆层组织及硬度的影响

在TC4合金和60^#钢表面进行了激光熔覆NiCrBSi涂层的试验,利用扫描电镜和X射线衍射仪等对激光熔覆层的组织、成分和物查进行了分析,测试了激光熔覆层的显微硬度。结果表明,激光熔覆层在微观结构上存在熔覆区、结合区、基体热影响区三个区域。在TC4合金表面熔覆区中出现了TiB2、TiC等新相,其显微硬度在HV900－1100之间,明显于60^#钢表面熔覆区的显微硬度（HV800－900）。     

NiCrSiB合金高功率激光送粉熔覆裂纹形成的敏感因素

用 4 5k W高功率激光器对 Ni Cr Si B合金在送粉激光熔覆下裂纹形成的材料成分、熔覆工艺、微观组织等因素进行研究。实验表明 ,裂纹是由于熔覆层中大量的多种硬质相以及硬质相的不良分布形态所造成的高脆性 ,难以承受熔覆过程产生的较大拉应力所致。解决激光熔覆层裂纹问题的主要方向应是从工艺上降低熔覆过程的残余拉应力 ,同时从成分搭配和快速凝固特性上使得 Ni Cr Si B熔覆层微观组织中的硬质强化相细小均匀地弥散析出 ,保证熔覆层的高强度和高塑性     

WC对316L钢表面的铁基激光熔覆涂层的性能影响研究

为进一步提高316L钢材的显微硬度，拓宽其使用范围，采用激光熔覆的方法，在316L钢材表面制备出不同比例的Fe60-WC熔覆层。研究不同比例的WC对熔覆层的截面组织、显微硬度、晶相构成的影响及原因。经过试验分析可知，当WC的质量分数为3%时，其与Fe60形成了硬质合金结构，增加了熔覆层的显微硬度。当WC的质量分数提升至5%时，熔覆层的微观结构发生了较大的改变，此时WC的质量分数虽然更多，但是熔覆层的显微硬度有所下降。结果表明，当WC的质量分数为3%时，熔覆层保持树形胞状晶，此时的显微硬度明显高于基体。     

Co/介孔WC激光复合涂层的显微结构与高温磨损性能研究

以H13钢为基体材料,以Co基合金和同粒径范围介孔WC的混合粉末为合金材料,采用半导体激光器在基体表面进行激光熔覆,通过介孔WC的特殊结构,获得均匀的高性能覆层。采用扫描电镜、能谱仪、X-射线衍射分析仪和显微硬度计研究熔覆层的显微组织、元素分布、相组成和显微硬度。利用高温磨损试验机对熔覆层在常温和高温下的磨损性能进行对比分析。结果表明,熔覆层主要由γ-Co以及碳化物硬质相WC、Cr3C2、(Cr,Co)23C6和Cr7C3组成。由于介孔WC颗粒对熔覆层的弥散强化和固溶强化的作用,激光熔覆层显微硬度比基体提高了2倍左右。在600℃高温下,由于碳化物硬质相的作用,熔覆层的高温耐磨性相比H13基体提高了3倍左右,熔覆层的高温磨损形式主要以氧化磨损为主。由于温度的升高,熔覆层表面形成氧化膜,从而对熔覆层进行有效保护,因此熔覆层的耐磨性随着温度的增加而提高。     

45#钢激光熔覆铁基合金组织及磨损性研究

利用CO2激光器在45#钢基体上熔覆Fe基合金,通过改变激光的扫描速度,分析了激光熔覆层的微观组织,测试了其显微硬度及磨损性能.结果表明,激光熔覆区为细小的树枝晶,组织均匀致密,随着扫描速度的增加,熔覆层的宽度呈下降趋势,熔覆层显微硬度是基体3.5倍.随着扫描速度的增加,熔覆层中颗粒相和合金元素的偏析减少,使硬度有所降低.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks