| The natural diamond tools is one of important tools for diamond ultra-precision cutting machining and related research work.Research reuult shows that:nanometer-scale sharpness edge has an important impact on surface quality of ultra-precision machining,in particular,the surface morphology of micro-geometry,if it has different sizes of sharpness,it will have a great distinctness on the surface of the workpiece geometry and physical and chemical parameters.Therefore,the edge sharpness of diamond tool is one of the important technical parameters for characterizing its performance.The current study shows that there are two major difficulties on measuring the sharpness of diamond tool:first,conventional contour measure equipment is not able to measure edge profile effectively,and second,evaluation theory for nano-scale edge sharpness of the circular blade diamond tool is not unified.Based on the analysis of key technology for measuring the edge sharpness of the circular blade diamond tool,we propose a method for measuring whole edge sharpness based on atomic force microscopy(AFM) and based a new type measuring system for edge sharpness of the diamond tool.AFM is the main platform of this system,which attached a sophisticated rotary flotation shaft and drive system,to achieve the controllable micro feed of a circular diamond blade in the direction of the edge and multi-point scanning edge parts when the tool is clamped once,to achieve an endirect measurement of the whole edge.This paper analyzes the sources of measurement error and clarifies sources of coupling and decoupling methods for radial rotating error of the flotation shaft and AFM scan error. The tests of the measuring system show that:the radial rotary precision,positioning accuracy and static measurement noise and many other indicators of the measuring system have reached requirements,and effectively suppressing noise on the observation results impact through the calibration of AFM.The evaluation methods of the edge sharpness of diamond tool are still existing deficiencies,the improvements are carried out in this paper.As we know,the section profile of diamond tool edge is from two straight lines and curves of a class composed of circular,generally considered the edge sharpness is characterized by a edge blunt radius.In this paper,we use a method based on the second curvature to separate the front and rear flank point and the arc poing to be fitted,the results show that the method is simple,fast and accurate. While from the actual process of the tool sharpening,we bring forward a point that a perfect blunt round and flank are tangent and based a least squares method model which is constrained by flank line and arc are tangent, this evaluation model of blade with actual income radius value more accord with situation morphology.This article attempts to start form analyzing affection that the whole edge sharpness effects on for surface quality,doing some exploration and research on the whole edge sharpness evaluation methods.Finally we analyze error in the sharpness evaluation process.We have done measurement experiment for the edge sharpness of diamond tool on measuring system.In local sharpness measurement experiment,when the level of sharpness siza is seventy nanometer,the measurement of results is about five nanometer. Several measurings shows that the results have good reproducible. We also have compared the results with other method's and ours'have higher precision and reliability.In whole sharpness mearsurement experiment,we have used statistical methods to token the whole edge sharpness by a lot of measuring times,the resultls coudle reflect the sharp performance of the cutting tool.This paper have researched on the exploration and evaluation of the edge sharpness of the circular arc diamond cutting tool through theoretical analysis and experiment.That results and conclusions obtained coudle provide a reference for evaluating quality of diamond tool and technical support for sharpening diamond tool. |
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