GPIB激光自动测径系统及逻辑分析仪的应用

激光测径仪可以对被测的直径进行精确地测量，但被测物所处的环境条件如灰尘、蒸汽等都会影响测量的精确性。本文介绍了一种基于GHB接口的激光测径自动测试系统，用于采集激光测径仪在各种干扰条件下的测量信号，并利用计算机对获得的数据进行处理，从而消除环境对测量结果精确性的影响，另外重点介绍了系统中逻辑分析仪的使用。     

Laser surface coating of Mo–WC metal matrix composite on Ti6Al4V alloy

Laser surface alloying of Mo, WC and Mo–WC powders on the surface of Ti6Al4V alloys using a 2 kW Nd-YAG laser was performed. The dilution effect upon the microstructure, microhardness and wear resistance of the surface metal matrix composite (MMC) coating was investigated. With a constant thickness of pre-placed powder, the dilution levels of the alloyed layers were found to increase with the incident laser power. The fabricated surface MMC layer was metallurgically bonded to the Ti6Al4V substrate. The microhardness of the fabricated surface layer was found to be inversely proportional to the dilution level. The EDAX and XRD spectra results show that new intermetallic compounds and alloy phases were formed in the MMC layer. With the existence of Mo content in the pre-placed powder, the β-phase of Ti in the MMC coating can be retained at the quenching process. With increasing weight percentage content of WC particles in the Mo–WC pre-pasted powder, the microhardness and sliding wear resistance of the laser surface coating were increased by 87% and 150 times, respectively, as compared with the Ti6Al4V alloy. The surface friction of the laser-fabricated MMC coatings was also decreased as compared with the worn Ti6Al4V substrate.     

The effects of laser-induced modification of surface roughness of Al2O3-based ceramics on fluid contact angle

Laser surface treatment of Al₂O₃-based refractory ceramics, by melting and re-solidification, can be successfully applied to producing surfaces that are pore-free, homogeneous and crack-free. Such treated surfaces can lead to an increase in the corrosion and erosion resistances of the materials, due to lower permeability to corrosive species and higher surface hardness, respectively. Furthermore, the corrosion resistance can be influenced by the wetting characteristics of the treated surfaces in service environment. Therefore, it is important to investigate the effect of laser treatment of ceramic materials on the interaction of the surface with the various environmental elements. This work is concerned with an experimental investigation of the effects of laser surface treatment, by melting and re-solidification, on the fluid contact angles of Al₂O₃-based refractory ceramics. These effects are examined by the modification of the surface roughness characteristics induced by laser treatment. Laser-treated surfaces, both containing cracks and crack-free, are compared with untreated surfaces and the results are reported. The untreated surfaces demonstrated considerable non-uniformity in wetting, in contrast to the treated surfaces. The extent of wetting of the laser-treated surfaces containing cracks was proportional to laser power density. This is due to wetting being enhanced, among other factors, by surface roughness, which increased with power density. The crack-free surfaces were the most smooth and, thereby, exhibited the smallest extent of wettability variations. The reduction in wettability after the laser treatment (crack-free) may have an advantage for corrosion resistance.     

Effects of various environments on fatigue crack growth in Laser formed and IM Ti–6Al–4V alloys

The fatigue crack growth behaviors of Laser formed and ingot metallurgy (IM) Ti–6Al–4V alloys were studied in three environments: vacuum, air and 3.5% NaCl solution. Taking the Unified Fatigue Damage Approach, the fatigue crack growth data were analyzed with two intrinsic parameters, stress intensity amplitude ΔK and maximum stress intensity K_max, and their limiting values ΔK^* and . Fatigue crack growth rates da/dN were found increase with stress ratio R, highest in 3.5% NaCl solution, somewhat less in air and lowest in vacuum, and higher in IM alloy than in Laser formed one. In 3.5% NaCl solution, stress corrosion cracking (SCC) was superimposed on fatigue at R=0.9 for where K_max>K_ISCC, the threshold stress intensity for SCC. This and environment-assisted fatigue crack growth were evidenced by the deviation in fatigue crack growth trajectory (ΔK^* vs. curve) from the pure fatigue line where . Furthermore, the fractographic features, identified along the trajectory path, reflected the fatigue crack growth behaviors of both alloys in a given environment.     

激光技术在微细加工中的应用

本文介绍了用于微细加工的激光器的种类和特点，阐述了激光技术在微细加工中的应用、国外的研制情况及其发展前景。     

高精度七米激光测长机的误差补偿技术

简要介绍一笔者研制的大型计量测试仪器－“高精度七米激光测长机及其计量管理系统”的工作原理，详细地介绍了其测量过程中采用的误差补偿技术并进行实验验证。     

Error Analysis for High-precision 7m Laser Measuring Machine

This paper introduces a high precision 7m laser measuring instrument developedby the anthors and its operating principle,and systematically analyses the errors havinginfluence on the performance of the measuring instrument.Error analysis and actualverification indicate that all the characteristics reached or exceeded the original designspecifications.     

求激光漫反射中心新算法

分析激光在作为测量光源的特点，提出使用三角形法进行快速尺寸测量时求激光漫 反射中心的新算法。     

身管内壁形貌检测技术研究

本文总结了国内外的身管检测技术 ,阐述了这些技术的测量原理及其优缺点。通过比较 ,指出激光投影法在身管内壁形貌检测方面有着良好的应用前景。     

用于100nm节点ArF准分子激光光刻的相移掩模技术

用于100nm节点ArF准分子激光光刻的相移掩模(PSM)技术主要有无铬相移掩模(CPM),交替相移掩模(APSM)、衰减相移掩模(AttPSM)和混合相移掩模技术。对这些掩模的基本原理、制作方法及性能比较进行了分析研究。研究表明,无铬相位光刻(CPL)PSM和高透AttPSM 相结合构成的混合掩模最适合用于193nmArF光刻,以产生100nm节点抗蚀剂图形。