Study on micro cutting fundamentals considering the cutting edge radius and the workpiece material in micro end milling

2020 ◽  
pp. 095440892094602
Author(s):  
Yang Li ◽  
Xiang Cheng ◽  
Siying Ling ◽  
Guangming Zheng ◽  
Huanbao Liu ◽  
...  
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Workpiece Material ◽  
Micro Cutting ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Micro End Milling

Previous studies found that the peripheral cutting edge and end cutting edge in micro end milling had different cutting phenomena considering the size effect in micro cutting processes. This paper is a further study on this point considering different workpiece materials and cutting edge radii. Finite element simulations have been conducted to determine the minimum undeformed chip thickness (MUCT) by the chip morphology and the results are verified by micromilling experiments. Both the simulations and experiments show that the MUCT of the peripheral cutting edge and the end cutting edge are different even if the cutting edge radii remain unchanged. The MUCT is directly proportional to the cutting edge radius. Material properties also have some effects on the MUCT of the peripheral cutting edge. But it has limited effects on that of the end cutting edge. The results indicate that the feed engagement other than the axial depth of cut should be carefully selected in micro end milling when considering different workpiece materials.

scholarly journals Reliability of Cutting Edge Radius Estimator Based on Chip Production Rate for Micro End Milling

2019 ◽  
Vol 3 (1) ◽  
pp. 25 ◽  
Author(s):  
Jue-Hyun Lee ◽  
Angela Sodemann
Keyword(s):  
Production Rate ◽  
End Milling ◽  
Detection Threshold ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Training Data ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Micro End Milling ◽  
Two Parameters

In this paper, the reliability of a new online cutting edge radius estimator for micro end milling is evaluated. This estimator predicts the cutting edge radius by detecting the drop in the chip production rate as the cutting edge of a micro end mill slips over the workpiece when the minimum chip thickness (MCT) becomes larger than the uncut chip thickness (UCT), thus transitioning from the shearing to the ploughing dominant regime. This study proposes a method of calibrating the cutting edge radius estimator by determining two parameters from training data: a ‘size filtering threshold’ that specifies the smallest-size chip that should be counted, and a ‘drop detection threshold’ that distinguishes the drop in the number of chips at the actual critical feedrate from the number drops at the other feedrates. This study then evaluates the accuracy of the calibrated estimator from testing data for determining the ‘critical feedrate’—the feedrate at which the MCT and UCT will be equal. It is found that the estimator is successful in determining the critical feedrate to within 1 mm/s in 84% of trials.

Investigation on Mechanism of Ultra-Smoothed Surface with a Micro Slot on the Flank Face in Micro Cutting

2014 ◽  
Vol 651-653 ◽  
pp. 764-767
Author(s):  
Tao Zhang ◽  
Hou Jun Qi ◽  
Gen Li
Keyword(s):  
Surface Roughness ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Back Side ◽  
Uncut Chip Thickness ◽  
Micro Cutting ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Flank Face ◽  
Side Flow

Micro cutting is a promising manufacturing method to obtain good surface integrity. Surface roughness shows size effect when the uncut chip thickness is smaller than the cutting edge radius. A special micro slot on the flank face of cutting tools was manufactured with discharge. Two groups of micro orthogonal cutting were conducted. The surface roughness of machined surface was measured and compared to each other. The results show that surface roughness decreases first and then increases with the ratio of uncut chip thickness to cutting edge radius. The surface machined with micro slot is better than that of without micro slot due to the micro slot restrain the back side flow of work piece based on the finite element model.

FE analysis of the effects of process representations on the prediction of residual stresses and chip morphology in the down-milling of Ti6Al4V

2021 ◽  
pp. 1-40
Author(s):  
Nejah Tounsi ◽  
Tahany El-Wardany
Keyword(s):  
Residual Stresses ◽  
Flank Wear ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Milling Process ◽  
Cutting Edge ◽  
Uncut Chip Thickness ◽  
Cutting Edge Radius ◽  
Edge Radius

Abstract In part II of these two-part papers, the effects of four FEM representations of the milling process on the prediction of chip morphology and residual stresses (RS) are investigated. Part II focuses on the milling of conventional uncut chip thickness h with finite cutting edge radius and flank wear, while part I of these two-part papers has reported on the results in the case of milling small uncut chip thickness in the micrometre range with finite cutting edge radius. Two geometric models of the flank-wear land composed of flat and curved wear land are proposed and assessed. The four process representations are: i) orthogonal cutting with flat wear land and with the mean uncut chip thickness h ¯; ii) orthogonal cutting with flat wear land and with variable h, which characterises the down-milling process and which is imposed on a flat surface of the final workpiece; iii) modelling the true kinematics of the down milling process with flat wear land and iv) modelling the true kinematics of the down milling process with curved wear land. They are designated as Cte-h, Var-h, True-h and True-h*. The effectiveness of these representations is assessed when milling Ti6Al4V with a flank-wear land of VB = 200µm.

scholarly journals Numerical Investigation on Effect of Rounded Cutting-Edge Radius and Machining Parameters in End Milling of AISI H13 Tool Steel

2018 ◽  
Vol 7 (4.30) ◽  
pp. 53
Author(s):  
Husni Nazra Abu Bakar ◽  
Jaharah A. Ghani ◽  
Che Hassan Che Haron
Keyword(s):  
Feed Rate ◽  
Cutting Tool ◽  
End Milling ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Aisi H13

Rounded cutting-edge radius is commonly applied to finish and semi-finish cutting, precision machining and micro-machining. The optimum effect is closely related to the work and tool material as well as machining parameters. However, for numerous cutting process, the optimal radius of rounded cutting-edge radius and machining parameters applied in the AISI H13 of end-milling is yet unknown Therefore, in improving tool life and cutting tool performance, a suitable design of cutting edge geometry regarding cutting edge-radius and machining parameters need to be examined and properly selected. In this regard, the paper deals to examine the effect of cutting edge-radius in rounded form and machining parameters of cutting force, cutting temperature and chip formation through the end-milling process of AISI H13 using uncoated cemented carbide cutting tool through finite element simulation of Thirdwave AdvantEdge 7.2 software. The machining parameters applied in the simulation setup were 200 and 240m/min of cutting speed, 0.03 and 0.06mm/tooth of feed-rate and axial depth of cut of 0.1 and 0.2mm while width of cut in radial direction was kept constant at 6.0mm. The cutting geometries includes the cutting-edge radius of 0.03 and 0.05mm and 10° of rake angle. The obtained results revealed that cutting forces and cutting temperature is increase as depth of cut in axial direction and cutting-edge radius increases while increasing value of speed and feed-rate of cutting resulted in decreasing cutting forces but increasing cutting temperature. The maximum cutting temperature is 674.91℃. The value obtained is lesser than the AISI H13 austenitizing temperature, therefore a layer known as white layer is supposedly hard to be created based on the cutting geometry and machining parameters applied.  

Investigation of Size Effect on Micro Hardness of Machined Surface in Micro Cutting

2014 ◽  
Vol 602-605 ◽  
pp. 443-446
Author(s):  
Tao Zhang ◽  
Zhen Yu Shi ◽  
Bing Yan ◽  
Hou Jun Qi
Keyword(s):  
Size Effect ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Three Dimension ◽  
Micro Hardness ◽  
Uncut Chip Thickness ◽  
Machined Surface ◽  
Micro Cutting ◽  
Cutting Edge Radius ◽  
Edge Radius

Micro cutting is a promising way for manufacturing micro parts, especially micro three dimension parts. Micro hardness is an important character to evaluate surface integrity of machined surface. Micro cutting is different from macro cutting due to size effect of specific cutting energy because of the influence of the ratio of uncut chip thickness to cutting edge radius. A group of micro cutting experiments were conducted to investigate the cutting parameters on the micro hardness of machined surface. The micro hardness of machines surface decreases with the ratio of uncut chip thickness to cutting edge radius first, and then increase when the uncut chip thickness is smaller than the cutting edge radius. The micro hardness shows size effect due to the machined surface compressed twice with the round cutting edge. The micro hardness decreases with the distance increasing far away from the machined surface.

Influence of Cutting Edge Radius in Micromachining AISI D2

2013 ◽  
Vol 393 ◽  
pp. 253-258 ◽  
Author(s):  
J.B. Saedon ◽  
A. Hakim A. Halim ◽  
H. Husain ◽  
M.S. Meon ◽  
Muhamad Fauzi Othman
Keyword(s):  
Chip Formation ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Element Analysis ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Material Deformation ◽  
Aisi D2 ◽  
Aisi D2 Tool Steel

Chip formation is a dynamic process that is often non linear in nature. A chip may not form when the depth of cut is less than a minimum chip thickness. This paper presents an investigation of cutting edge radius effect on micromachining AISI D2 tool steel via simulation. The chip growth, chip formation and material deformation mechanism was investigated using commercial finite element analysis software. A model is developed with consideration of the arbitrary LagrangianEulerian (ALE) method. The chip growth, chip formation and material deformation was investigate under three criteria such as a/r<1, a/r>1 and a/r=1. The model showed that the chip is formed at a/r >1 while material extrusion performed under a/r<1.

scholarly journals Investigation on the size effect in micro end milling considering the cutting edge radius and the workpiece material

2021 ◽  
Vol 12 (1) ◽  
pp. 487-499
Author(s):  
Yang Li ◽  
Xiang Cheng ◽  
Guangming Zheng ◽  
Huanbao Liu
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Chip Morphology ◽  
Cutting Edge ◽  
Workpiece Material ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Element Simulation ◽  
Cutting Experiment ◽  
Cutting Mechanisms

Abstract. Previous research has found that the peripheral and end cutting edges of the cutter had different cutting mechanisms in the micro end cutting process considering the size effect. This investigation is a further study on this point considering the cutting edge radius of the cutter and the material of the workpiece based on the methods of finite element simulation and the micro end cutting experiment. This study adopts a combination of simulation and experiment research methods and the cutting edge radius and the workpiece material as two variables. Considering the cutting mechanisms of the peripheral cutting edge and the end cutting edge are different, the peripheral cutting edge and the end cutting edge are studied respectively. Meanwhile, the minimum undeformed chip thickness (MUCT) value is determined in three ways, chip morphology, cutting force, and surface roughness, so the final result obtained by comparing three kinds of results has a very important reference value. Not only are the chip morphology obtained by finite element simulation and the surface roughness obtained by the micro end cutting experiment used to identify the MUCT value, but also the cutting force. The simulation and experimental results show that the cutting force can be used to identify the MUCT value for the peripheral cutting edge, but it cannot be used for the end cutting edge. The MUCT value increases with the increase of the cutting edge radius, no matter which process it is. The material property has some effects on the MUCT value; even the cutting parameters and the cutting edge radius remain unchanged for the peripheral cutting edge. However, the material property has no effect on the MUCT value for the end cutting edge. In this study, the influence of important variables on MUCT is studied as much as possible to reflect a real application situation.

Quantitative Microstructural Analysis of Nanocrystalline Surface Layer Induced by a Modified Cutting Process

2013 ◽  
Vol 769 ◽  
pp. 109-115 ◽  
Author(s):  
Volker Schulze ◽  
Frederik Zanger ◽  
Florian Ambrosy
Keyword(s):  
Surface Layer ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Microstructural Analysis ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Surface Layers ◽  
Workpiece Material ◽  
Cutting Edge Radius ◽  
Edge Radius

Present work analyzes the influence of process and modified geometry parameters of an orthogonal final machining process (finishing) on the nanocrystalline surface layers generation by quantitative microstructural analysis. Thereby, AISI 4140 (German Steel 42CrMo4) in a state quenched and tempered at 450°C is used as workpiece material. Metallic materials used in technical applications are polycrystalline in nature and are composed of a large number of grains which are separated by grain boundaries. The grain size has a strong influence on the mechanical material properties. Metallic parts with a severe nanocrystalline grain refinement in the near-surface area show many beneficial properties. Such surface layers considerably influence the friction and wear characteristics of the workpiece in a subsequent usage as design elements working under tribological loads due to their extreme superplastic properties. The tribologically induced surface layers formation already starts during the manufacturing of the components, by leading to a change of workpiece material near the surface. Particularly when the depth of cut h becomes of the same order as the cutting edge radius rß, the ploughing process becomes increasingly important and strongly influences the chip formation process. The plastic zone depth within the surface layer is especially influenced by the design of the microgeometry of the cutting tools and increases almost linearly with the ratio of cutting edge radius rß to depth of cut h. The plastic zone is hereby approximately of the same order of magnitude as the cutting edge radius rß. Parameters that are studied and taken into account in the manufacturing process are cutting edge radius rß, depth of cut h and cutting velocity vc. Variations of cutting depth h are performed in a range of 30 to 100 µm and variations of cutting edge radius rß are executed in a range of 30 to 150 µm. The microgeometries of the tools are preconditioned by abrasive grinding with a drag finishing machine and observed by a confocal light microscope. A cutting velocity vc of 25 and 150 m/min is applied. The evaluation of the manufacturing process is carried out by detailed analyses of the microstructural conditions in the surface layer after processing using a Focused Ion Beam system. These material characterizations provide information about the surface engineering concerning the microstructural changes in the workpiece surface layer due to machining. Hereby, the grain size analysis is investigated by a line method based on the characterization of portions of several test-lines positioned across the two dimensional Focused Ion Beam images.

Micro Flat End Milling Simulation Model With Instantaneous Plowing Area Prediction

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Abdolreza Bayesteh ◽  
Junghyuk Ko ◽  
Martin Byung-Guk Jun
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
End Milling ◽  
Chip Thickness ◽  
Depth Of Cut ◽  
Uncut Chip Thickness ◽  
Chip Area ◽  
Edge Radius ◽  
Wide Range ◽  
Radial Depth

There is an increasing demand for product miniaturization and parts with features as low as few microns. Micromilling is one of the promising methods to fabricate miniature parts in a wide range of sectors including biomedical, electronic, and aerospace. Due to the large edge radius relative to uncut chip thickness, plowing is a dominant cutting mechanism in micromilling for low feed rates and has adverse effects on the surface quality, and thus, for a given tool path, it is important to be able to predict the amount of plowing. This paper presents a new method to calculate plowing volume for a given tool path in micromilling. For an incremental feed rate movement of a micro end mill along a given tool path, the uncut chip thickness at a given feed rate is determined, and based on the minimum chip thickness value compared to the uncut chip thickness, the areas of plowing and shearing are calculated. The workpiece is represented by a dual-Dexel model, and the simulation properties are initialized with real cutting parameters. During real-time simulation, the plowed volume is calculated using the algorithm developed. The simulated chip area results are qualitatively compared with measured resultant forces for verification of the model and using the model, effects of cutting conditions such as feed rate, edge radius, and radial depth of cut on the amount of shearing and plowing are investigated.

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