共查询到20条相似文献,搜索用时 0 毫秒
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Y. -C. Yen J. S hner H. Weule J. Schmidt T. Altan 《Machining Science and Technology》2002,6(3):467-486
In metal cutting, tool wear on the tool-chip and tool-workpiece interfaces (i.e. flank wear and crater wear) is strongly influenced by the cutting temperature, contact stresses, and relative sliding velocity at the interface. These process variables depend on tool and workpiece materials, tool geometry and coatings, cutting conditions, and use of coolant for the given application. Based on the predicted temperatures and stresses on the tool face from the finite element analysis (FEA) simulation, tool wear may be estimated with acceptable accuracy by incorporating an empirical wear model.
The overall objective of this study is to develop a methodology to predict the tool wear evolution and tool life in orthogonal cutting using FEM simulations. To approach this goal, the methodology is proposed with three different parts. In the first part, a tool wear model for the specified tool-workpiece pair is developed via a calibration set of tool wear cutting tests in conjunction with cutting simulations. In the second part, modifications are made to the commercial FEM code used to allow for tool wear calculation and tool geometry updating. The last part includes the validation of the developed methodology. This paper is mainly focused on the modifications made to the commercial FEM code in order to make reasonable tool wear estimates (the second part). 相似文献
The overall objective of this study is to develop a methodology to predict the tool wear evolution and tool life in orthogonal cutting using FEM simulations. To approach this goal, the methodology is proposed with three different parts. In the first part, a tool wear model for the specified tool-workpiece pair is developed via a calibration set of tool wear cutting tests in conjunction with cutting simulations. In the second part, modifications are made to the commercial FEM code used to allow for tool wear calculation and tool geometry updating. The last part includes the validation of the developed methodology. This paper is mainly focused on the modifications made to the commercial FEM code in order to make reasonable tool wear estimates (the second part). 相似文献
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《Machining Science and Technology》2013,17(3):467-486
In metal cutting, tool wear on the tool-chip and tool-workpiece interfaces (i.e. flank wear and crater wear) is strongly influenced by the cutting temperature, contact stresses, and relative sliding velocity at the interface. These process variables depend on tool and workpiece materials, tool geometry and coatings, cutting conditions, and use of coolant for the given application. Based on the predicted temperatures and stresses on the tool face from the finite element analysis (FEA) simulation, tool wear may be estimated with acceptable accuracy by incorporating an empirical wear model. The overall objective of this study is to develop a methodology to predict the tool wear evolution and tool life in orthogonal cutting using FEM simulations. To approach this goal, the methodology is proposed with three different parts. In the first part, a tool wear model for the specified tool-workpiece pair is developed via a calibration set of tool wear cutting tests in conjunction with cutting simulations. In the second part, modifications are made to the commercial FEM code used to allow for tool wear calculation and tool geometry updating. The last part includes the validation of the developed methodology. This paper is mainly focused on the modifications made to the commercial FEM code in order to make reasonable tool wear estimates (the second part). 相似文献
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Raja Kountanya 《Machining Science and Technology》2013,17(4):429-452
The development of a general 3D model for a corner-radiused, chamfered, edge-honed cutting worn tool is elaborated. The surface of the cutting tool was constructed using one angular scalar specifying location on the corner radius and leading/trailing edges and another non-dimensional scalar for specifying location on the relief, edge-hone, chamfer and tool-top. Then, for given geometric parameters and cutting conditions, the angular extremities of contact on the corner radius and leading/trailing edges was obtained and validated. The kinematic surface finish on the workpiece surface including the Brammertz and sideflow effects was then simulated in typical hard turning. The model was expanded to allow wiper edges and flank wear. A simplified crater wear model was adopted for continuous hard turning to allow virtual cross-sectioning. Accurate estimation of flank and crater wear volume was also enabled. The model results for the fresh tool agreed with well-known trends from 2D modeling. Preliminary results indicate that there exists a geometric basis for higher Ra and Rt for a worn tool. The Brammertz effect simulation, though not in agreement with the data of Knuefermann (2003) corroborated the modification proposed therein. 相似文献
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This paper presents a discriminant feature selection approach for hidden Markov model (HMM) modeling of micro-milling tool conditions. The approach is compared with other popular feature selection methods such as principal component analysis (PCA) and automatic relevance determination (ARD) according to their HMM classification rate. In tool condition monitoring (TCM), there are a lot of features that contain redundant information or less sensitive to tool state discrimination. These features are expected to be deleted for less computation and more robust modeling of tool conditions. Fisher's linear discriminant analysis (FDA) is modified for this purpose. The FDA is generally used for classification, and the features are mapped to another space and lose their physical meanings. In the modified discriminant feature selection, the features are selected in the original feature space by maximizing tool state separation and ranked by their separation ability between different tool states. Experimental results from both micro-milling of copper and steel under different working conditions indicate that the FDA is superior to both PCA and ARD for feature selection in HMM's classification. The reasons behind these differences are also discussed. 相似文献
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为研究刀具磨损的微观机理,以单晶铝为例,采用分子动力学方法对纳米切削中刀具失效的原子级物理本质进行研究。模拟结果显示,随着切削深度的增加,能够形成化学键的配对原子数也急剧增加,导致刀具的扩散磨损加剧;晶体的各向异性对刀具扩散磨损影响很小,说明扩散磨损主要是一种化学过程;扩散磨损生成的积屑瘤代替刀具进行切削,使得超精密加工的表面质量恶化,切削区域温度上升,进一步加剧扩散磨损过程。 相似文献
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以小波分析理论为基础,提出了以对数熵理论确定最佳小波包分解树结构的方法,提出了基于声发射信号最佳小波基最佳小波分量频段能量的声发射信号小波特征,开发了基于最佳小波基小波特征的神经网络刀具磨损状态在线监测系统,实验结果表明,该系统具有较高的监测精度,能满足工业现场对刀具磨损状态实时在线监测的要求. 相似文献
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Bin Zou Chuanzhen Huang Jinpeng Song Hanlian Liu Hongtao Zhu 《Machining Science and Technology》2013,17(2):192-205
A type of Si3N4-based nanocomposites ceramic cutting tool material was prepared by the addition of nano-scale Si3N4W whisker and nano-scale TiN particle. Cutting performance of the Si3N4/Si3N4W/TiN nanocomposite ceramic tool in machining of cast iron was investigated in comparison with a commercial sialon ceramic tool, and the tool wear mechanism was studied. The two types of cutting tools have similar cutting performance at relatively low cutting parameters, while Si3N4/Si3N4W/TiN nanocomposite tool exhibits a better wear resistance than sialon tool at the relatively high cutting parameters. The wear of sialon ceramic cutting tool is dominated by the plastic deformation, abrasive action, microcracking, pullout of grains and chemical action at the higher cutting parameters. The higher mechanical properties, and the refined matrix grains, intragranular TiN grains and dislocation in the microstructure improve the resistances to plastic deformation, microcracking, and pullout of grains for Si3N4/Si3N4W/TiN nanocomposite ceramic cutting tool. The wear of Si3N4/Si3N4W/TiN nanocomposite ceramic cutting tool is dominated by the abrasive and chemical actions at the higher cutting parameters. 相似文献
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This paper examines the performance of AlN/TiN coated carbide tool during milling of STAVAX® (modified AISI 420 stainless steel) at a low speed of 50 m/min under conventional flood and mist lubrication. Abrasion, chipping, fracture resulting in the formation of crater and catastrophic failure are the wear mechanisms encountered during machining under flood lubrication. The flank wear, and the likeliness of the cutting tool to fracture, chip and fail prematurely increased with an increase in the hardness of the workpiece and a reduction in the helix angle of the tool. Small quantity of mineral oil sprayed in mist form was effective in reducing the flank wear and severity of abrasion wear, and preventing the formation of crater and the occurrence of catastrophic failure. In milling 35 and 55 HRC-STAVAX® using a feed rate of 0.4 mm/tooth and a depth of cut of 0.2 mm under mist lubrication, the cutting edge of the 25° and 40° helix angle tools only suffered small-scale edge chipping and abrasive wear throughout the entire duration of testing. The influence of the ductility of the workpiece on the surface finish and the effectiveness of mist lubricant in improving the surface finish are also discussed. 相似文献
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A NEW CONCEPT FOR DECOUPLING THE CUTTING FORCES DUE TO TOOL FLANK WEAR AND CHIP FORMATION IN HARD TURNING 总被引:1,自引:0,他引:1
Determining the temperature field in metal cutting when the tool flank is progressively worn requires the knowledge of the forces due to tool flank wear and that due to chip formation. In the past, these forces have been computed from data experimentally measured with a dynamometer, under the assumption that the chip formation configuration remained unaltered when the tool flank is progressively worn. This approach has been used in the literature even though there has been evidence that it is not correct. The error introduced by this doubtful assumption in computing the maximum surface temperature in the work-piece can be significant.
Of late there has been considerable interest in employing hard turning as the final finishing process in place of grinding and superfinishing. Consequently, the ability to accurately predict the maximum surface temperature and its distribution in the workpiece is now most desirable, for avoiding thermal damage to the machined surface. This paper discusses a new method based on the thickness of the microstructural change in chips to decouple the tool-flank forces for predicting the maximum surface temperature and its distribution in the workpiece. 相似文献
Of late there has been considerable interest in employing hard turning as the final finishing process in place of grinding and superfinishing. Consequently, the ability to accurately predict the maximum surface temperature and its distribution in the workpiece is now most desirable, for avoiding thermal damage to the machined surface. This paper discusses a new method based on the thickness of the microstructural change in chips to decouple the tool-flank forces for predicting the maximum surface temperature and its distribution in the workpiece. 相似文献
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Chongyang Gao 《Machining Science and Technology》2013,17(1):26-40
Titanium alloy Ti6A14V has been widely used in many engineering fields due to its attractive specific strength and corrosion resistance. A deep understanding of the material's machinability is of primary importance. This article investigates the serrated chip formation mechanism of Ti6Al4V alloy under high-speed cutting by finite element analysis. The effect of the cutting conditions on the serrated chip formation is analyzed comprehensively. The study found that when the initial chip thickness becomes small or when the rake angle becomes large, the size of sawtooth decreases and the number of sawtooth increases. The serrated chip morphology is more sensitive to the initial chip thickness. The severe fluctuation of cutting forces is caused by the formation of sawtooth in chipping. To minimize the serrated chipping in high-speed machining, the initial chip thickness is the most important factor to consider. 相似文献