金属加工机械制造业关键技术分析——超精密加工技术

１．技术概要机械制造技术在提高精度方面，从精密加工发展到超精密加工，其精度从微米级提高到亚微米级，乃至纳米级。就目前的加工技术而言，超精密加工技术是为了获得零件加工的尺寸精度、形状精度和表面粗糙度均优于亚微米级的综合技术措施，并向纳米级加工发展。纳米级加工是指零件加工的尺寸精度、形状精度和表面粗糙均为纳米级（＜１０nm，即＜０．０１μm）。超精密加工主要包括超精密切削（车、铣）、超精密磨削、超精密研磨（机械研磨、机械化学研磨、研抛、非接触式浮动研磨、弹性发射加工等）以及超精密特种加工（电子束、离子…     

国内纳米级超精密磨床研制成功

洛阳传顺机械设备有限公司研制成功国内首台纳米级超精密磨床——超精密气静压轴承套圈沟道磨床,并获得国家发明专利。该机采用了具有自主知识产权的三轴气浮技术(工件轴、砂轮轴、修整器回转轴),其加工圆度精度达到了0.1μm以内,跨入了纳米级超精密加工领域。可广泛用于航空航天、半导体、光学部件、超精密轴承(P2级)等领域里的加工。     

精密超精密加工及现代精密测量技术

论述精密超精密加工的技术内涵和范畴，分析影响精密超精密加工的主要因索．并指出当前国内外精密超精密加工技术研究中的一些关键技术和重点．此外对精密超精密加工中的微／纳米级精密测量技术、误差建模和补偿技术进行介绍。     

用于超精表面分析的宽范围扫描隧道显微镜

本文描述了一种能检测超精密度表面纳米级超微观形貌的扫描隧道显微镜，该装置可测到高定向石墨表面原子图象和精密光栅，金刚石切削表面和精密磨削表面的纳米级形貌。     

我国超精密光学零件加工技术跨入世界领先行列

<正>由国防科技大学机电工程与自动化学院自主研制的新一代超精密光学零件加工设备,日前通过相关单位组织的工艺考核。结果表明,该套设备加工精度实现亚纳米级重大突破,其典型试验件的光学零件面形精度RMS(均方根)值达到0.361纳米,标志我国超精密光学零件加工技术跨入世界领先行列。超精密加工技术是先进装备制造的关键性瓶颈技术,纳米精度被誉为超精密加工技术"皇冠上的明珠"。过去,由于我国光学零件加工技术落后,无法进行大口径、高精     

超精密加工的发展状况及影响表面质量若干因素的分析

文章就超精密加工的应用领域进行了简述,介绍了超精密制造技术的发展状况及其发展方向,对影响超精密加工表面质量的因素进行了理论分析.指出超精密加工表面质量是由于多种因素影响形成的,提高加工表面质量的核心是降低各子集的分维数.分维数越高振动规律越复杂,其微细结构越复杂,对纳米级超精密加工表面质量影响越大.     

《2018-2019机械工程学科发展报告(机械制造)》——机械制造学科标志性研究进展

正在精密与超精密加工领域,清华大学路新春等建立了大尺寸表面纳米级平坦化的加工原理与方法,发明了系列大尺寸超薄硅片纳米级无损伤抛光关键技术,研制开发出12英寸"干进干出"化学机械抛光(CMP)装备与成套工艺,实现了IC制造大尺寸晶圆表面的纳米级平坦化及纳米级缺陷控制。整体技术达到国际先进水平,已在中芯国际等企业实现批量应用,打破了国外高端微电子超精密抛光装备长期垄断的局面。     

国内外超精密加工技术与机床的发展状况

1 前言 超精密加工是指亚微米级和纳米级精度的加工.超精密加工主要包括3个领域:(1)超精密切削加工,如金刚石刀具的超精密切削,各种镜面及激光核聚变系统和天体望远镜的大型抛物面镜的加工.     

MoS2/Zr复合涂层高速钢刀具的切削性能研究

综合考虑了工件表面原子的微观状态,利用纳米颗粒特殊的高比表面能和高吸附特性,提出了一种可实现工件表面原子级去除的纳米胶体射流抛光方法。利用碱性胶体中纳米颗粒与工件的表面反应,设计了可实现超精密表面加工的纳米胶体射流抛光系统,并利用该系统对K9玻璃进行抛光。试验结果表明,纳米胶体射流抛光可实现超精密光学表面的抛光,抛光后表面粗糙度Ra小于1nm。      

超精密纳米胶体射流抛光试验研究

综合考虑了工件表面原子的微观状态,利用纳米颗粒特殊的高比表面能和高吸附特性,提出了一种可实现工件表面原子级去除的纳米胶体射流抛光方法.利用碱性胶体中纳米颗粒与工件的表面反应,设计了可实现超精密表面加工的纳米胶体射流抛光系统,并利用该系统对K9玻璃进行抛光.试验结果表明,纳米胶体射流抛光可实现超精密光学表面的抛光,抛光后表面粗糙度Ra小于1nm.     

高增益PID控制器实现纳米定位

建立了高增益PID闭环控制系统,在"直流伺服电机＋滚珠丝杠"驱动机构上实现了大范围的纳米定位。对于"伺服电机＋滚珠丝杠"驱动系统来说,摩擦是实现纳米定位精度的主要障碍,它影响着系统微动特性并导致稳态误差。针对这种驱动系统,在根据标定参数计算得到的线性传递函数的基础上,设计高增益不完全微分、比例反馈PID控制器,配置闭环控制系统的极点为负实轴上的多重极点,避免了摩擦力建模和补偿。实验结果表明,该高增益闭环控制系统有效地抑制了摩擦等非线性因素的影响,在系统的宏动和微动特性阶段都可以实现单步的纳米定位并取得了一致的响应,10 nm~10 mm阶跃响应的稳态误差不超过±2 nm。     

精密定位平台的系统误差分析及螺距误差补偿方法的实现

简要地介绍了研制的大行程纳米定位系统宏动工作台的组成,详细地分析了其系统误差特性及几种误差补偿方法。实验表明,通过双向螺距误差补偿法可使其定位精度得到较大的改善。     

Simple positioner with nanometer reproducibility of the focused light beam position on an object

A simple positioner, which allows one to ensure the position of a focused light beam on an object with nanometer precision and reproducibility, is proposed and studied. It can be used for positioning of focused beams (in particular, laser beams) on surfaces of optical fibers, biological objects, optical disks, thin film modulators, and holographic memory systems in the micrometer and nanometer ranges.     

一种毫微米级进给机构几个问题的研究

通过建模的方法对所研制的一种毫微米级微进给机构的原理进行了分析,结合实验结果提出了有关结构参数的设计要点。并从动静态的角度分析了其定位精度的影响因素,提出了减少误差、提高系统稳定性的措施。     

基于自校正的纳米工作台控制

利用在线参数估计和自校正控制算法设计一个自校正控制器,以解决纳米工作台因各参数变化而其精确的数学模型难以确定,因而影响定位精度的问题。Matlab仿真结果表明该算法能够克服由扰动引起的系统参数变化对系统精度的影响,其控制性能优良。     

Development of a novel 3-degrees of freedom flexure based positioning system

Flexure mechanisms have been widely used for nanometer positioning systems. This article presents a novel conceptual design of an ultra-precision 3-degrees of freedom (XYθ(Z)) positioning system with nanometer precision. The main purpose of this novel stage design is for the application of measurement equipment, in particular biological specimens. The stage was designed as a hollow type and with a compact size for the inverted microscope. This stage includes piezoelectric transducer actuators, double compound amplification mechanisms, moving plate, and capacitor sensors. The double compound amplification mechanism was designed using a mathematical model and analyzed by the finite element method. Since the relationship between the variables of the hinge parameters and system performances are complicated, an optimization procedure was used to obtain the optimal design parameters, which maximized the system bandwidth. Based on the solution of the optimization problem, the design of the stage and FEM simulation results are presented. Finally, the stage was manufactured and tested.     

Submicrometer overshoot control of rapid and precise positioning

Precise-positioning technique is relatively well developed. However, it is still difficult to avoid an overshoot or to limit the overshoot within a submicrometer in a rapid and precise positioning. Inspired by recent studies on microdynamics, a control algorithm based on the variable structure control (VSC) method is proposed to achieve an overshoot smaller than 0.2 μm and rapid, precise positioning (a 0.5 mm 1 cm positioning with a steady-state error smaller than 30 nanometer in 0.5 s) with a linear motor drive stage. The stage is guided by a rolling ball guide and with a 10 nm resolution laser interferometer as its position sensor. Some characteristic values in the friction model of microdynamics are included to design the controller. Therefore, we found a way to achieve rapid, precise, and Small overshoot positioning by combining mechanism design system identification, lubrication, and controller design techniques.     

Nano positioning control for dual stage using minimum order observer

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE.     

Dynamic responses of a precision positioning table impacted by a soft-mounted piezoelectric actuator

The piezoelectric actuator, lead zirconate titanate (PZT) actuator, has been used for precision positioning from micrometer down to nanometer scale. In this paper, a soft-mounted PZT actuator is designed with a low-stiffness spring element to achieve a high-accuracy and large-displacement characteristic in precision positioning motion. The motion of the sliding table, the contact force between the hammer and the sliding table, and the stick-slip frictional force caused by the grinded groove are investigated. The governing equations of the distributed and lumped parameter systems are formulated to obtain the dynamic responses, which agree well with the experimental results.     

Dynamic adhesive force measurements under vertical and horizontal motions of interacting rough surfaces

An instrument to measure dynamic adhesive forces between interacting rough surfaces has been developed. It consists of four parts, namely, main instrument body, vertical positioning system with both micrometer and nanometer positioning accuracies, horizontal positioning system with nanometer positioning accuracy, and custom-built high-resolution, and high dynamic bandwidth capacitive force transducer. The vertical piezoelectric actuator (PZT) controls the vertical (approaching and retracting) motion of the upper specimen, while the horizontal PZT controls the horizontal (reciprocal) motion of the lower specimen. The force transducer is placed in line with the upper specimen and vertical PZT, and directly measures the adhesive forces with a root-mean-square load resolution of 1.7 microN and a dynamic bandwidth of 1.7 kHz. The newly developed instrument enables reliable measurements of near-contact and contact adhesive forces for microscale devices under different dynamic conditions. Using the developed instrument, dynamic pull-in and pull-off force measurements were performed between an aluminum-titanium-carbide sphere and a 10 nm thick carbon film disk sample. Three different levels of contact force were investigated; where for each contact force level the vertical velocity of the upper sample was varied from 0.074 to 5.922 microms, while the lower sample was stationary. It was found that slower approaching and retracting velocities result in higher pull-in and pull-off forces. The noncontact attractive force was also measured during horizontal movement of the lower sample, and it was found that the periodic movements of the lower disk sample also affect the noncontact surface interactions.