天然金刚石刀具的研磨及其刃口半径检测技术

指出了天然金刚石刀具的刃口锋利度对现代超精密切削加工的重要影响,介绍了国内外天然金刚石刀具研磨技术的发展现状,以及我国金刚石刀具刃磨技术中普遍存在的问题。详细叙述了对刃磨后刀具刃口半径检测的几种可行方法,展望了刃口半径检测技术的前景。     

用原子力显微镜扫描测量金刚石刀具刃口半径

介绍了应用原子力显微镜（ＡＦＭ）扫描测量超精密加工用金刚石刀具刃口半径的方法,给出了测量图象和测量结果。该方法可提高金刚石刀具刃口半径的测量精度,对进一步分析刃口参数对超精密加工表面质量的影响具有一定指导意义。     

钝化参数对刀具刃口钝圆半径影响的研究

刀具刃口钝化通过消除刃口上的微观缺口,改变切削刃的微观形貌,实现增加刀具的寿命,提升刀具的切削性能,使已加工零件获得更好地表面质量的目的。基于立式旋转钝化特点,获得了刀具刃口的运行轨迹。对硬质合金刀具采取立式旋转钝化的方式进行钝化,通过刀具钝化实验,并通过扫描电子显微镜对钝化后的刀具刃口钝圆半径进行测量,研究刀具转速和钝化时间对刀具刃口钝圆半径的影响规律,为优化刀具钝化工艺参数和提高刀具刃口钝化效率提供依据。     

硬质合金钻头刃口钝圆及其半径的测量

指出了硬质合金钻头刃口钝圆对切削加工的影响,说明了硬质合金钻头刃口钝圆的重要性,简要介绍了刃口钝圆的方法及常规的测量方法,提出了在Matlab中用最小二乘法拟合的数据处理方法来获得刀口钝圆半径值.与传统测量方法相比,此方法避免了常规测量方法所产生的人为的不确定因素,减少了由于测量系统的精确度引起的误差,可以准确地判断是否达到钝化参数的要求,对优化刀具结构设计、提高切削性能、增加刀具使用寿命有重要的作用和实际意义.     

钝圆半径对镍基高温合金的铣削性能影响

铣削典型的难加工材料镍基高温合金时,刀具刃口直接接触参与切削,对铣削性能起到决定性作用.通过建立刀具精确三维模型和有限元切削仿真模型,对不同钝圆半径的圆角铣刀铣削镍基合金进行仿真,分析钝圆半径对切削性能的影响,开展切削试验进行验证.结果 表明:钝圆半径对刃口附近集中区域的应力和温度以及进给抗力和切深抗力影响较为显著;钝...     

钝圆半径对刀具硬态切削性能的影响研究

为了揭示修圆刃口对刀具硬态切削性能的影响规律,以5种钝圆半径的修圆刃口为研究对象,运用金属切削软件AdvantEdge对淬硬轴承钢进行干式车削仿真。结果表明,主切削力F_c和进给力F_f均随钝圆半径的增加而变大;刀具高温区面积随着钝圆半径的增加而扩大,最高切削温度均位于切削刃附近;钝圆半径对刀具最大应力值的影响较小。研究结果可为刀具刃口形式和参数的合理选择提供理论指导。     

AFM检测金刚石刀具锋利度误差分析研究

金刚石刀具是超精密切削的重要工具,其刃口锋利度的好坏对工件切削质量有着直接影响。基于AFM的金刚石刀具刃口锋利度检测是目前的主要方法,但是由于AFM仪器本身、扫描参数设置以及刀具状况、外界干扰等多种影响因素的作用,将导致金刚石刀具纳米级锋利度的检测产生多种误差。以圆弧刃金刚石刀具为测量对象,深入分析各个因素的影响过程,进行了理论分析和实验过程,提出了抑制和修正方法。研究表明,通过上述研究和措施的实施,可以提高锋利度的检测精度,为金刚石刀具高质量评价体系的建立提供理论和方法支持。     

硬质合金立铣刀刃口钝化参数对钝圆半径的影响

通过立式旋转钝化机对硬质合金立铣刀进行刃口钝化,研究了钝化速度、钝化时间、磨粒粒度、磨粒类型等钝化参数对钝圆半径的影响规律,采用数学回归方法建立钝圆半径的数学模型,并通过方差分析验证了该预测模型的正确性,为刀具钝化刃口优化和实现高速高效切削加工奠定基础。     

硬质合金刀具刃口形状对高温合金切削力的影响

硬质合金刀具是切削高温合金等难加工材料的常用工具，其刃口形状会对加工性能产生重要影响，钝圆半径与形状因子是目前刃口形状的常用特征参数。为研究刃口形状对加工高温合金时切削力的影响，使用硬质合金刀具对Inconel 718高温合金开展侧铣试验。试验结果表明，形状因子相同但钝圆半径不同的刃口所产生的切削力不同，钝圆半径相差越小其产生的切削力偏差越小。当钝圆半径一致且形状因子K>1时，加工所产生的切削力随形状因子的增大而增大。刃口的钝圆半径越小，其形状因子对切削力的影响越显著。本文提出了研究刃口形状时应同时考虑钝圆半径与形状因子的重要性，并研究了形状因子对切削力的影响，对合理选择刃口的形状有重要意义。     

一种基于AFM的金刚石刀具刃口锋利度的检测方法

金刚石刀具刃口纳米级别的锋利度是影响超精密加工表面质量特别是表面微观几何形貌的重要因素.针对目前测量中存在的问题,介绍了一种新的使用原子力显微镜(Atomic Force Microscope,AFM)进行金刚石刀具刃口锋利度检测的方法,该方法首先利用仿射变换进行截面数据提取,然后利用一种基于曲率的算法求出圆弧拟合点,...     

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.     

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.     

A study of the effect of tool cutting edge radius on ductile cutting of silicon wafers

Ductile mode cutting of silicon wafers can be achieved under certain cutting conditions and tool geometry. An experimental investigation of the critical undeformed chip thickness in relation to the tool cutting edge radius for the brittle-ductile transition of chip formation in cutting of silicon wafers is presented in this paper. Experimental tests for cutting of silicon wafers using diamond tools of different cutting edge radii for a range of undeformed chip thickness are conducted on an ultra-precision lathe. Both ductile and brittle mode of chip formation processes are observed in the cutting tests. The results indicate that ductile cutting of silicon can be achieved at certain values of the undeformed chip thickness, which depends on the tool cutting edge radius. It is found that in cutting of silicon wafers with a certain tool cutting edge radius there is a critical value of undeformed chip thickness beyond which the chip formation changes from ductile mode to brittle mode. The ductile-brittle transition of chip formation varies with the tool cutting edge radius. Within the range of cutting conditions in the present study, it has also been found that the larger the cutting edge radius, the larger the critical undeformed chip thickness for the ductile-brittle transition in the chip formation.     

金刚石刀具刀尖几何形状对超精密切削加工质量的影响

指出超精密切削实际上是刀具刀尖部分与工件的相互作用,分析了金刚石刀具刀尖几何形状和切削刃的锋利度对超精密切削加工质量的影响。认为正确地选择刀尖部分几何形状和修光刃钝圆半径是获得高质量加工表面的有力保证。     

Investigation of the effect of cutting tool edge radius on material separation due to ductile fracture in machining

This paper investigates the interaction between cutting tool edge radius and material separation due to ductile fracture based on Atkins’ model of machining. Atkins’ machining model considers the energy needed for material separation in addition to energies required for shearing at the primary shear zone and friction at the secondary shear zone. However, the effect of cutting tool edge radius, which becomes significant at microcutting conditions, was omitted. In this study, the effect of cutting tool edge radius is included in the model and its influence on material separation is investigated. A modification to the solution methodology of Atkins’ machining model is proposed and it is shown that the shear yield stress and the fracture toughness of the work material can be calculated as a function of uncut chip thickness.     

金刚石刀具刃口轮廓新型检测方法与技术

研究了原子力显微镜扫描方式及原子力微探针坐标方式的刃口轮廓测量技术。原子力探针新型检测方法与技术可以在亚微米尺度内很好地克服传统测量方法精确度低的缺点，而且操作简便，为目前超精密加工领域中金刚石刀具研磨技术水平的提高提供了有利的技术手段。     

基于数据拼接的金刚石刀具刃口三维形貌表征技术

原子力显微镜(AFM)是获取金刚石刀具刃口纳米级三维形貌的重要手段,但其存在测量范围小,难以表征参与切削区域整段刃口形貌特征的问题。采用基于迭代最近点法的刃口AFM测量数据拼接算法,获得了由多组数据拼接得到的刃口纳米级三维形貌,并进行了切削实验验证。实验结果表明,采用的数据拼接方法可较好地用于表征刀具刃口三维形貌。     

A study on critical depth of cuts in micro grooving

Ultra precision diamond cutting is a very efficient manufacturing method for optical parts such as HOE, Fresnel lenses, diffraction lenses, and others. During micro cutting, the rake angle is likely to become negative because the tool edge radius is considerably large compared to the sub-micrometer-order depth of cut. Depending on the ratio of the tool edge radius to the depth of cut, different micro-cutting mechanism modes appear. Therefore, the tool edge sharpness is the most important factor which affects the qualities of machined parts. That is why diamond, especially monocrystal diamond which has the sharpest edge among all other materials, is widely used in micro-cutting. The majar issue is regarding the minimum (critical) depth of cut needed to obtain continuous chips during the cutting process. In this paper, the micro machinability near the critical depth of cut is investigated in micro grooving with a diamond tool. The experimental results show the characteristics of micro-cutting in terms of cutting force ratio (Fx/Fy), chip shape, surface roughness, and surface hardening near the critical depth of cut.