金刚石刀具刀尖圆弧波纹度的测量及评价

为实现金刚石刀具刀尖圆弧波纹度超精密测量,构建了基于原子力显微镜(AFM)和精密回转轴系的刀尖圆弧轮廓测量系统,研究了刀尖圆弧波纹度评价方法和控制测量系统引入误差的策略。提出了评价刀尖圆弧波纹度时截止波长的确定原则和方法,并介绍了刀尖圆弧波纹度测量原理及评价流程。讨论了精密回转轴系径向回转误差的测量和评定、刀具安装偏心和偏角误差的控制和原子力扫描系统Z向非线性误差的校准方法。最后,在构建的测量系统上测量了了金刚石刀具刀尖圆弧波纹度并对测量不确定度进行了分析。实验测量显示:所评价金刚石刀具的刀尖圆弧波纹度为0.106μm,测量不确定度为23.8nm,表明所构建的测量系统基本满足金刚石刀具刀尖圆弧波纹度纳米级测量及评价的需求,测量结果稳定可靠、精度高。     

SiCp/Al复合材料超精密车削表面质量的影响因素

选择天然单晶金刚石和聚晶金刚石刀具,研究了增强颗粒质量分数(0～20%)、进给量(1～10 μm/r)、刀尖圆弧半径(0.4～1.6 mm)和刀具材料等因素对SiCp/Al复合材料超精密车削表面质量的影响.结果表明:在试验条件下,加工表面粗糙度Ra随SiC含量的增加而显著增大,且加工表面的微坑洞、微裂纹和划痕等缺陷也显著增多;增大进给量,刀具-工件相对振动幅度增大,且加工表面的增强颗粒拔出、破碎现象增多;刀尖圆弧半径减小,表面粗糙度轮廓波动幅值增大,频谱图中进给分量对应的峰值更为显著;虽然单晶金刚石和聚晶金刚石刀具可获得相同或相近的Ra,但后者获得的表面含有更多的加工缺陷.     

微圆弧金刚石刀具刃磨关键技术及应用

微圆弧金刚石刀具是实现微结构功能表面机械加工的必备工具之一,高性能刀具可提高微结构表面精度和质量一致性。针对机械刃磨技术,研究微圆弧金刚石刀具的定向设计、制造工艺和装备,分析不同定向刀具的切削刃强度与其刀刃圆弧波纹度、锋利度和耐用度的关系。结果表明,微圆弧金刚石刀具的使用性能与其定向方案有关;针对不同定向的刀具,采用专门的刃磨工艺参数可减小因定向不同导致的刀具质量差异。采用最新研制的金刚石刀具专用刃磨机床,可以获得刀刃圆弧波纹度优于30 nm/60°包角、锋利度优于50 nm的微圆弧金刚石刀具。     

SiCp／AI复合材料超精密车削表面质量的影响因素

选择天然单晶金刚石和聚晶金刚石刀具，研究了增强颗粒质量分数（0-20％）、进给量（1～10μm／r）、刀尖圆弧半径（0．4～1．6mm）和刀具材料等因素对SiCp／A1复合材料超精密车削表面质量的影响。结果表明：在试验条件下，加工表面粗糙度R。随SiC含量的增加而显著增大，且加工表面的微坑洞、微裂纹和划痕等缺陷也显著增多；增大进给量，刀具一工件相对振动幅度增大，且加工表面的增强颗粒拔出、破碎现象增多；刀尖圆弧半径减小，表面粗糙度轮廓波动幅值增大，频谱图中进给分量对应的峰值更为显著；虽然单晶金刚石和聚晶金刚石刀具可获得相同或相近的Ra，但后者获得的表面含有更多的加工缺陷。     

一种新型稳健样条轮廓滤波器

在表面计量学中,通常利用轮廓滤波器提取轮廓中线作为表面评定的基准线。由于传统轮廓滤波器极易受到划痕和深谷等奇异信号影响而产生失真甚至错误的中线,为了增强其稳健性并保证评定精度,国际标准中给出了两种替代滤波器,即稳健型样条滤波器和高斯回归滤波器。然而,这两种滤波器的构造原理和实现算法迥异,其滤波特性差异较大,从而导致对同一表面具有不同的评定结果。为解决这一问题,提出将M估计权函数与样条滤波器相结合构造了一种新型稳健样条滤波器。该滤波器不但具有更强的抗差能力,其计算效率也远高于国际标准推荐的稳健滤波器。更重要的是,大量实验表明,其滤波特性与高斯回归滤波器接近,该滤波器的应用有助于表面评定标准的传递和测量结果比对。     

单点金刚石切削加工表面粗糙度的影响因素分析

本文研究了单点金刚石切削加工表面微观形貌形成机理,建立了圆弧刃金刚石刀具超精密加工表面微观形貌的理论模型,重点分析了主轴转速、进给量、刀尖圆弧半径和振动等因素对超精密加工表面粗糙度的影响。     

刀尖圆弧半径对金刚石薄膜涂层刀具耐冲击性的影响

通过断续车削试验研究了刀尖圆弧半径对金刚石薄膜涂层刀具耐冲击性的影响,指出适当增大刀尖圆弧半径可有效提高金刚石薄膜涂层刀具的耐冲击性。     

正弦波微结构的超精密加工技术研究

阐述了同轴调制正弦波微结构的加工原理。结合试验分析讨论了刀具刀尖圆弧半径、被加工材料、切削液等切削条件与主轴转速和刀具进给速度等切削用量对金刚石超精密切削加工后的微结构功能表面的影响。为复杂微结构的金刚石超精密加X-技术研究积累了一定经验。     

圆弧刃金刚石刀具研抛新方法及微摆幅机构设计

圆弧刃金刚石刀具制造的目标是获得刃口锋利、刀尖圆弧轮廓精度高和刃口表面质量高的金刚石刀头,其研抛工艺一直是国内外研究的热点。为提高圆弧刃金刚石刀具研抛效率和研抛质量,提出了微摆辅助机械研抛方法,理论分析表明该方法能有效提高金刚石刀具的研抛效率和研抛质量。对实现该方法的微摆幅机构进行设计和有限元模态分析,研究结果对微摆幅机构微摆频率的选择具有重要指导意义,为微摆幅机构的结构改进提供了依据。     

高斯滤波技术提取表面粗糙度信息

在传统高斯滤波理论的基础上,提出稳健高斯滤波算法,引入M估计中的权函数对高斯滤波进行稳健处理,并结合高斯滤波逼近理论,在高斯滤波稳健算法基础上,构建高斯滤波的算法模型和零件表面形貌特征模型。利用MALTAB软件编程和仿真模拟系统,模拟出零件表面原始轮廓信号,并采用simulink系统仿真设计出FIR型数字高斯滤波器。将原始轮廓信号通过高斯滤波器,通过一次有效滤波分离提取出零件表面的粗糙度信号和滤波中线,实现高斯滤波的过程,提取粗糙度信息来评定零件表面质量。     

An integrated method for measurement of diamond tools based on AFM

The measurement and evaluation technology of high precision diamond tools is critically important for supporting the ultra-precision machining. In practical cutting process, the edge profile quality of the diamond tool, including sharpness, micro defects, roughness and tip arc waviness, greatly affects the cutting quality. It is very difficult to measure and evaluate the diamond tool edge profile due to the high precision of tool edge profile and complexity of various measurement parameters. In this paper, an integrated method for measurement and characterization of diamond tools is proposed, which is based on an Atomic Force Microscope (AFM) module. Multiple technical indexes of diamond tools are obtained and validated based on the presented research and cutting experiments, and the evaluation model for each technical index is also proposed. The integrated measurement equipment, including an AFM, precision adjustment device and aerostatic bearings, has been established based on the accuracy requirement of measurement parameters. The edge sharpness, micro defects, surface roughness and tip arc waviness have been obtained based on the evaluation model and experimental data. The experimental results show that the measurement accuracy meets the requirements of the comprehensive evaluation of the diamond tool edge profile. The research work will also contribute to the development of ultra-precision machine.     

High-order spline filter: Design and application to surface metrology

The differences between the transmission characteristics of the standard cubic spline filter and the Gaussian filter lead to different evaluation results even for the same profile. There is indeed an adverse impact on the comparison of measurement results and the applications of the related international standards. A novel high-order spline filter is proposed to resolve this practical problem of approximating the Gaussian filtering characteristic. The design of the new filter is based on an improved variational approach by adding the high order derivative terms to the bending energy part whose structural parameters are determined by the aid of the universal Taylor series, so as to realize the convergence to the function of the Gaussian filter. In addition, a cascade algorithm in terms of the low-order filters is also developed in order to ensure stable performance of the high-order filter. Its effectiveness and application were verified by the experiments.     

Fitting of robust reference surface based on least absolute deviations

Engineering surfaces comprise shape deviations namely form, waviness and roughness. For characterization of roughness, form and waviness are separated from the measured surface by establishing a reference surface that represents these deviations. This paper presents a new approach of simultaneously separating form and waviness deviations by fitting a reference surface that remains robust against the outliers such as deep grooves. A second degree polynomial and a set of sinusoidal functions are taken as basis functions to represent form and waviness respectively. A criterion of minimization of sum of absolute deviations (L₁-norm) is considered as against the commonly used least squares (L₂-norm) criterion and the reference surface obtained is found to be robust against outliers such as deep valleys in the measured surface. The superiority of the proposed fitting scheme is brought out by testing on different surfaces and comparing with the least squares method of fitting and the robust Gaussian regression filtering.     

超精铣削转鼓六面体反射镜面的金刚石铣刀头

简要介绍超精铣削转鼓六面体反射镜面的金刚石铣刀头的结构、几何参数和主要工艺。通过详细计算和比较阐明了具有凸圆弧前刀面的金刚石铣刀头能铣削粗糙度Ra值达到几个纳米,反射镜面的波纹度P-V值达亚微米级的理论依据。     

An edge reversal method for precision measurement of cutting edge radius of single point diamond tools

A method, which is referred to as the edge reversal method, is proposed for precision measurement of the cutting edge radius of single point diamond tools. An indentation mark of the cutting edge which replicates the cutting edge geometry is firstly made on a soft metal substrate surface. The cutting edge of the diamond tool and its indentation mark, which is regarded as the reversal cutting edge, are then measured by utilizing an atomic force microscopy (AFM), respectively. The cutting edge radius can be accurately evaluated through removing the influence of the AFM probe tip radius, which is comparable to the cutting edge radius, based on the two measured data without characterization of the AFM probe tip radius. The results of measurement experiments and uncertainty analysis are presented to demonstrate the feasibility of the proposed method.     

磨损表面的稳健高斯滤波评定方法研究

磨损表面形貌的评定方法,对于磨损表面状态评定、摩擦特性的分析有着重要的作用,而表面形貌数据的滤波方法,是评定方法中的关键组成之一。采用Tukey、Hampel、IGGI和QC 4种典型稳健权函数分别与高斯滤波结合组成的稳健高斯滤波方法,对由实验得到的黏着磨损和磨料磨损盘表面采集的数据进行稳健滤波分离;通过由稳健高斯滤波与标准高斯滤波得到的三维磨损表面低频基准面的对比分析,以及从磨损表面滤波分离出的高频评定参数的影响分析,研究稳健高斯滤波的滤波稳健性和滤波效率;从滤波后的高频功率谱密度分布特性方面,进一步探讨滤波的稳健性;讨论磨损表面形貌数据中特异值与磨损特征的关系。研究表明：Tukey和Hampel稳健高斯滤波具有良好的滤波稳健性,能有效地分离磨损表面的低频评定基准和包含磨损特征的高频信息;而磨损特征主要分布在高频信息的低频段区间,其功率谱密度函数与表面磨损状态及其摩擦学特性相关。     

车削加工陶瓷材料时刀具磨损表面形态的研究

分别使用硬质合金刀具、金刚石刀具、立方氮化硼刀具对氟金云母陶瓷及二硅酸锂玻璃陶瓷材料进行车削试验。利用显微镜观察刀具磨损形貌,通过能谱分析研究了刀具的磨损机理。试验结果表明,刀具磨损部位主要集中在刀尖和后刀面,刀具磨损形式主要为磨料磨损和粘结磨损。用硬质合金刀具车削氟金云母陶瓷时,切削深度越小,磨料磨损越严重。     

凸圆弧前刀面铣刀头超精铣削时主要参数对粗糙度及残留面积的影响

通过详细推算,给出凸圆弧前刀面金刚石铣刀头超精铣削平面时的理论表面粗糙度和切削残留面积的计算公式.利用所得的公式,进一步分析了凸圆弧半径、走刀、后角及安装误差角等主要参数对它们的影响.其Ra值可达几个纳米、P-V值达亚微米级.