软X射线投影光刻的关键技术

1．多层膜反射镜是投影光刻得以实现的前提．必须解决多层膜的高反射率、带宽匹配、应力，曲面基板上膜厚随入射角变化而变化等关键问题．目前，Mo／Be和Mo／Si多层膜在11～14mm波段得到了接近70％的反射率。2．光学元件超精密加工与检测是投影光刻得以实现的另一大基础。软X射线投影光刻所用的光学元件不仅要有较高的面形精度，而且要有较低的表面粗糙度。美国Tinsley公司现在能加工面形误差精度达0．6nm的元件，这是目前世界上最高的光学加工水平。为检测所加工元件的面形误差，该公司采用了精密干涉测量法、STM和AFM技术等当今最先…     

大口径光学元件的精密磨抛与检测装备开发及应用

大口径光学元件超精密加工是一个复杂的系统性工程,涉及精密机床、数控、加工技术与工艺、精密检测和补偿控制等机电控各领域的专业知识,其发展与一个国家的高端制造技术及装备发展能力息息相关,也是一个国家综合国力的集中体现。主要介绍了厦门大学微纳米加工与检测联合实验室在大口径光学元件超精密加工技术及装备方面取得的研究进展,针对大口径光学元件磨削和抛光两个加工流程及其配套的精密检测技术,详细阐述了磨削装备及单元技术、可控气囊抛光机床及相关单元技术、精密检测装备及相关单元技术等的研究应用情况。这些技术研究从超精密加工的需求出发,借鉴国内外的研究经验和成果,通过对装备、工艺、检测等各方面整合,形成了具有自主知识产权的集磨削、抛光和检测装备及工艺技术的大口径光学元件超精密加工体系,这些技术与装备确保了大口径光学元件的高质量超精密加工。     

复杂曲面铝反射镜磁流变抛光工艺优化

采用超精密车削加工的复杂曲面铝反射镜只能满足红外光学系统的应用需求,若要满足更高需求的应用场合,需要进一步提升反射镜面形精度。磁流变抛光能够进行确定性修形,在复杂曲面加工中具有独特优势,但是复杂曲面连续变化的面形特征,在磁流变抛光时会导致去除函数不稳定,影响误差收敛效率和加工精度。从高精度复杂曲面铝反射镜的应用需求出发,提出了复杂曲面局部区域磁流变抛光去除函数的动态建模方法,给出了驻留时间求解算法,以平均曲率变化最小为原则,设计了抛光路径优化算法,针对该算法计算速度慢的问题,提出了优化策略,并通过试验进行了验证,最终加工的复杂曲面铝反射镜的面形误差为0.216λ PV、0.033λ RMS （λ=632.8 nm）。     

Zernike自由曲面加工轨迹规划研究

Zernike自由曲面光学元件加工复杂,采用单点金刚石慢刀伺服车削方法可以实现自由曲面光学元件的高效、高精度制造。本文针对慢刀伺服车削Zernike自由曲面刀具等角度法和等弧长法两种车削轨迹划分方法进行研究,并选择等角度法轨迹划分进行车削工艺实验,获得了口径50mm的Zernike自由曲面光学元件,面形精度PV0.9506μm。     

国内首台工程实用化超精密非球面加工机床

非球面曲面超精密复合加工系统是具备金刚石车削、铣削和磨削功能的CNC超精密加工系统,用于平面、球面及非球面光学零件的超精密加工。加工面形精度PV=0.228μm,表面粗糙度Ra=0.0078μm。该系统的研制成功,标志着我国在本领域的研究已跨入实用化、工程化的阶段,研究项目进入国际先进行列。国内首台工程实用化超精密非球面加工机床     

科技成果

我国先进制造技术取得新突破 日前,由中国航空精密机械研究所研制的非球面曲面超精密加工机床成功交付用户。 非球面曲面超精密加工机床具备超精密金刚石车削、铣削功能和超精密金刚石砂轮磨削功能及其他相应辅助功能,主要用于完成超精密平面、球面以及包括非球面曲面等在内的复杂面形光学零件的超精密加工。     

实现太赫兹波高透射率的微结构超精密加工技术

为针对提高太赫兹波透射率的需求,开展基于离子注入表面改性的脆性材料微结构超精密加工技术的研究,并将其应用于太赫兹波产生用磷化镓微棱锥结构的应用中。通过蒙特卡洛模拟指导注入参数,对比脆塑转变深度验证机械加工效果,成功加工出符合应用要求的微结构。通过光学测试,该方法能够有效提高加工效率,改善加工质量,实现对脆性光学材料的一次成型加工。     

《航空精密制造技术》2003年总目录

◇精密加工基于超声研磨的超精密加工………………………………(1)精密加工中非球面工件面形精度的在机测量……………(1)基于小型三坐标测量机的机械研究………………………(1)超光滑表面清洗技术现状及其发展趋势…………………(2)激光陀螺超光滑反射镜基片的光学加工和检测技术……(2)光纤连接器超精密加工技术的研究………………………(3)智能材料在微机械中的应用及发展………………………(3)超精密车削表面三维微观形貌仿真及特征分析…………(4)卫星轴承钢珠精化技术研究………………………………(4)基于AFM电场诱导氧化的纳米加工…     

非球面模芯ELID磨削技术研究

采用铸铁结合剂、CBN砂轮,利用ELID磨削加工技术,对GCr15轴承钢的磨削性能进行实验研究;并利用自行开发的非球面数控磨削系统,对GCr15材料非球面模芯进行超精密数控磨削加工,加工后工件表面粗糙度Ra36nm,面形精度小于5μm。     

超精密加工技术的发展

以单点金刚石车削和超精密金刚石磨削为基础的超精密加工能够经济地制造光学、机械和电子部件,或生产在微米和毫微米范围内的成形精度和表面粗糙度的产品。辅助成形精度和表面粗糙度测量技术在评估超精密加工表面质量中也起着重要作用。在香港建立了超精密加工中心,用各种设备和技术服务帮助当地企业对高质量超精密产品进行快速研制和试验超精密加工技术的发展     

有翼高超声速再入飞行器气动设计难点问题

有翼高超声速再入飞行器是近年来的研究热点,气动设计是飞行器设计的关键。为了更清楚地认识有翼高超声速再入飞行器气动设计的难点问题,对有翼高超声速再入飞行器的发展、优势及总体任务剖面进行了介绍,从5个方面详细介绍了该类飞行器气动设计的难点问题,包括多约束复杂面对称气动布局设计、高温真实气体效应对气动特性影响、天地差异与天地换算方法、反作用控制系统(RCS)喷流干扰对气动特性的影响以及气动数据不确定度等,简要阐明了这些难点问题对总体设计的重要性以及初步的解决思路,为有翼高超声速再入飞行器气动设计提供了一些参考。     

Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters

Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks.     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

突破技术趋同，波音再现竞争优势

 波音公司面临着来自空客公司的巨大挑战,企业战略性创新才是公司成功的关键。为此波音公司的全部战略性研究集中在扩大产品的差异性上,体现在3个方面：电子化（e-Enabled）运营环境、整体复合材料机身部件的制造技术和支持波音787客机的全球协同环境（GCE）。     

临近空间飞行器测控与信息传输系统频段选择

 临近空间飞行器是高性能信息化武器平台,测控（TT&;C）与信息传输系统是其信息保障的核心,而选择合理、可行的频段是展开系统设计的前提和基础。频段选择影响到整个技术方案的制定,是一个需综合考虑、影响深远并具有战略意义的关键问题,从国际电联（ITU）国际标准、高速数传、接收信噪比（SNR）、“三抗”、超视距中继、黑障、雨衰以及设备研制成熟度8个方面全面、细致论证了近空间平台测控系统的频段选择问题,最终得出在视距链路中以Ka频段为宜,在超视距链路中以Ku/Ka双频段为宜的结论。     

基于弯曲激波压缩系统的高超声速进气道反设计研究进展

总结了近十年来弯曲激波压缩研究的主要成果。提出了弯曲激波压缩系统的新概念,即利用特殊设计的楔形弯曲压缩面或空间弯曲压缩面,产生一系列与前缘弱激波相互交汇或叠加的压缩波系,从而使前缘激波弯曲,形成特殊的弯曲激波,它与波后的等熵压缩波来共同完成对气流的压缩。在此基础上,实现了由给定出口气动参数的超声速内流道反设计,实现了由给定压缩面压力分布和给定压缩面马赫数分布要求的型面反设计,实现了由给定激波波面的压缩型面反设计。研究证明,弯曲压缩面-弯曲激波压缩系统具有良好的综合气动性能,为高性能高超声速进气系统的气动设计提供了一种全新的设计方法。     

Experimental Study on Effects of Fuel Injection on Scramjet Combustor Performance

In order to investigate the effects of fuel injection distribution on the scramjet combustor performance, there are conducted three sets of test on a hydrocarbon fueled direct-connect scramjet test facility. The results of Test A, whose fuel injection is carried out with injectors located on the top-wall and the bottom-wall, show that the fuel injection with an appropriate close-front and centralized distribution would be of much help to optimize combustor performances. The results of Test B, whose fuel injection is performed at the optimal injection locations found in Test A, with a given equivalence ratio and different injection proportions for each injector, show that this injection mode is of little benefit to improve combustor performances. The results of Test C with a circumferential fuel injection distribution displaies the possibility of ameliorating combustor performance. By analyzing the effects of injection location parameters on combustor performances on the base of the data of Test C, it is clear that the injector location has strong coupled influences on combus- tor performances. In addition, an inner-force synthesis specific impulse is used to reduce the errors caused by the disturbance of fuel supply and working state of air heater while assessing combustor performances.     

(高)超声速流动试验技术及研究进展

近年来,与高速飞行器相关的(高)超声速流动受到了极大的关注。这类流动所具有的非定常性、强梯度和可压缩性对试验方法和风洞设计技术提出了挑战。超声速纳米示踪平面激光散射(NPLS)技术是由作者所在团队研发的非接触光学测试技术。它能够以较高的空间分辨率来揭示超声速三维流场的一个瞬态剖面的时间解析的流动结构。介绍了NPLS技术以及基于NPLS开发的密度场测量、雷诺应力测量和气动光学波前测量等方法,并回顾了这些技术在超声速边界层、超声速混合层、超声速压缩拐角、激波/边界层相互作用和光学头罩绕流等流动中的应用,清晰地再现了边界层、混合层、激波等典型流场结构及其时空演化特性。另外,为了模拟和研究高空大气条件下边界层自然转捩和超声速混合层的转捩特性,介绍了高超声速静风洞、超-超混合层风洞的设计技术以及层流化喷管的设计方法。     

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.