固着磨料加工工艺对磷酸盐钕玻璃亚表面缺陷的影响

散粒磨料研磨与固着磨料研磨是光学研磨加工过程中的两种主要手段,但两者材料去除的机制不同。目前针对高功率固体激光装置中的主要工作物质——磷酸盐激光钕玻璃的亚表面缺陷(SSD)研究相对较少,因此在实验的基础上,通过系统地研究固着磨料对磷酸盐激光钕玻璃的研磨工艺过程,分析了多种因素,如磨料粒径、载荷大小、机床转速,以及结合剂材料与冷却液等对钕玻璃亚表面缺陷形成的影响,并与散粒磨料研磨工艺所产生的亚表面缺陷进行了比较,对关键工艺参数进行定量,为高质量钕玻璃制造工艺的选型以及进一步优化亚表面缺陷提供了重要的参考数据。

Subsurface damage of Nd-doped phosphate glasses in optical fabrication

We present a destructive method for detecting and measuring subsurface damage of Nd-doped phosphate glasses. An instrument based on the dimple method - a destructive method - was developed. Subsurface damage depth produced in each fabrication procedure was obtained. We extend the surface roughness-subsurface damage relation to Nd-doped phosphate glasses. The constant ratio of subsurface damage and surface roughness was obtained as well. We also analyse the relation of abrasive size and subsurface damage experimentally. From a measurement of the surface roughness or abrasive size, one can obtain an accurate estimate of the damage layer thickness that must be eliminated by polishing or subsequent grinding operations. (C) 2007 Elsevier GmbH. All rights reserved.

磷酸盐钕玻璃表面/亚表面损伤特性实验研究

系统地研究了光学研磨过程中,磨料粒径、载荷大小以及机床转速对钕玻璃表面及亚表面损伤的影响。结果表明,机床转速和载荷基本不改变材料表面粗糙度,而较大载荷或较低机床转速产生较大的亚表面缺陷,表面粗糙度和亚表面缺陷缺陷深度基本与最大磨料粒径呈正比,载荷增倍使亚表面缺陷与表面粗糙度的常数比值增加0.05。研究结果为钕玻璃加工工艺改进提供了参考依据。

The effects of sapphire substrates processes to the LED efficiency - art. no. 68410M

We investigate the relation between the thickness of sapphire substrates and the extraction efficiency of LED. The increasing about 5% was observed in the simulations and experiments when the sapphire thickness changed from 100um to 200um. But the output power increasing is inconspicuous when the thickness is more than 200um. The structure on bottom face of sapphire substrates can enhance the extraction efficiency of GaN-based LED, too. The difference of output power between the flip-chip LED with smooth bottom surface and the LED with roughness bottom surface is about 50%, where only a common sapphire grinding process is used. But for those LEDs grown on patterned sapphire substrate the difference is only about 10%. Another kind of periodic pattern on the bottom of sapphire is fabricated by the dry etch method, and the output of the back-etched LEDs is improved about 50% than a common. case.

ELECTRICAL CHARACTERS OF OXYGEN DEFECTS IN SILICON SUBJECTED TO INTRINSIC GETTERING TREATMENT

The influence of oxygen defects on the resistivity and mobility of silicon wafers is discussed. Grinding processes were performed on the surfaces of samples in order to obtain the information on interior defects of the samples. Spreading resistivity and Hall measurements prove that SiO(x) complexes alone result in resistivity increase and mobility decrease. Deep level transient spectroscopy experiments prove that SiO(x) complexes alone are electrically active. A mechanism of carrier scattering by electrically active SiO(x) complex is proposed to explain the changes of resistivity and mobility.

Fractal roughness characterization of super-ground Mn-Zn ferrite single crystals

The surface of superground Mn-Zn ferrite single crystal may be identified as a self-affine fractal in the stochastic sense. The rms roughness increased as a power of the scale from 10(2) nm to 10(6) nm with the roughness exponent alpha = 0.17 +/- 0.04, and 0.11 +/- 0.06, for grinding feed rate of 15 and 10 mu m/rev, respectively. The scaling behavior coincided with the theory prediction well used for growing self-affine surfaces in the interested region for magnetic heads performance. The rms roughnesses increased with increase in the feed rate, implying that the feed rate is a crucial grinding parameter affecting the supersmooth surface roughness in the machining process.

机器人研磨抛光工艺研究与实现

机器人研磨抛光工艺研究建立在大量机器人磨抛试验的基础上。本文针对加工对象——有机玻璃,在满足被加工工件质量的前提下,确定了机器人研磨抛光加工时磨片的合理使用顺序、规划加工路径和安排正交试验,以获得机器人磨抛加工的最优工艺参数组合,并制定机器人磨抛的加工策略。最后通过机器人研磨抛光加工实例,进一步验证了机器人的研磨抛光工艺知识有其合理性。

五轴磨抛机器人补偿算法研究与实现

通过分析基于模型的补偿方法和非模型补偿方法的优缺点,结合一个五轴磨抛机器人的结构特点,提出了两种补偿方法相结合的混合补偿算法.针对平移关节误差的主要来源难于建模的特点,采用非模型的方法进行补偿;针对转动关节误差主要来源为几何参数误差,能够建模,但有些参数随机器人末端位置不同而变化的特点,采用二者相结合的混合方法进行补偿.通过对该机器人系统的实验,验证了方法的有效性和可行性.

研磨抛光机器人运动控制器设计与研究

本文设计了研磨抛光机器人运动控制器的核心硬件结构和软件模块,采用了参数模糊自整定PID机器人关节位置控制策略,通过实验表明该运动控制器可以大大降低研磨抛光机器人的位置跟踪误差。建立的模块化的软件体系,便于运动控制器的维护和扩展,并可将其应用到其它工业机器人上。

基于ARM的研磨抛光机器人运动控制器的设计

本文设计了研磨抛光机器人分布式控制系统中的一种运动控制器,并对运动控制器基于AT91M40800微控制器的硬件结构、基于μC/OS-Ⅱ实时操作系统的软件模块和采用的参数模糊自整定PID机器人关节位置控制策略进行了详细介绍。实验表明该控制器可以大大降低研磨抛光机器人的位置跟踪误差。提高了关节控制的计算及处理能力,易于扩展和维护。

机器人研磨抛光工艺研究

以有机玻璃为研究对象,介绍了机器人研磨抛光工艺,讨论了研磨抛光参数优化设计方法,并进行了研磨抛光试验。试验结果表明,研磨抛光后的工件,能够达到产品外形和表面质量的要求,且提高了磨抛效率。

基于PSO的球磨机粉磨系统自适应模糊控制

提出了一种基于粒子群算法优化(PSO)的模糊控制器,对模糊控制器参数进行全局优化,以弥补模糊控制器参数在线调节方面的不足,并应用于球磨机粉磨系统的控制中。控制系统采用粒子群优化模糊控制器作为双闭环控制中的成品流量控制器,并在Matlab/Simulink进行的仿真分析中实现模糊控制器参数的在线调节。仿真结果表明,系统较好地实现了给定参考轨迹自适应跟踪,具有鲁棒性强、控制精度高等优点。

机器人化三腿磨削机床的研制

以钢坯修磨为实用目的研制的一台机器人化三腿机床，具有刚度大、负载能力强、机构简单、工作空间大、无运动耦合及奇异位形等优点，首次解决了钢坯局部修磨自动化问题，配以其它加工执行器还可实现多种工艺要求。建立了该机床的运动学逆、正解方程，对其工作空间和受力分析进行了介绍，并介绍了局部修磨自动化控制系统