Whirling Vibration in Drilling. Part 3: Vibration Analysis in Drilling Workpiece with a Pilot Hole

1988 ◽  
Vol 110 (4) ◽  
pp. 315-321 ◽  
Author(s):  
S. Ema ◽  
H. Fujii ◽  
E. Marui
Keyword(s):  
Frictional Force ◽  
Vibration Analysis ◽  
Cutting Edge ◽  
Chatter Vibration ◽  
Workpiece Surface ◽  
Pilot Hole ◽  
Regenerative Effect ◽  
Wave Forms ◽  
Vibration Wave ◽  
Flank Surface

The whirling vibration of the drill when beginning the drilling of a workpiece with a pilot hole, is theoretically examined. It becomes clear that the whirling is a regenerative chatter vibration which is caused by the regenerative effect at the major cutting edge and the frictional force occurring due to the interference between the flank surface of the major cutting edge and the workpiece surface. As the amplitude and the vibration speed of the drill are restricted by the characteristic of the frictional force, distinctive vibration wave forms are observed. It is also found that the frequency of the whirling vibration which is decreased by the frictional force, is considerably lower than the natural frequency of the system, and that the odd number polygon is produced by the regenerative effect.

scholarly journals Cutting Performance of Different Coated Micro End Mills in Machining of Ti-6Al-4V

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 568 ◽  
Author(s):  
Zhiqiang Liang ◽  
Peng Gao ◽  
Xibin Wang ◽  
Shidi Li ◽  
Tianfeng Zhou ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Edge ◽  
Micro Milling ◽  
End Mill ◽  
Coating Materials ◽  
Edge Chipping ◽  
Workpiece Surface ◽  
Micro End Mill ◽  
End Mills ◽  
Flank Surface

Tool wear is a significant issue for the application of micro end mills. This can be significantly improved by coating materials on tool surfaces. This paper investigates the effects of different coating materials on tool wear in the micro milling of Ti-6Al-4V. A series of cutting experiments were conducted. The tool wear and workpiece surface morphology were investigated by analyzing the wear of the end flank surface and the total cutting edge. It was found that, without coating, serious tool wear and breakage occurred easily during milling. However, AlTiN-based and AlCrN-based coatings could highly reduce cutting edge chipping and flank wear. Specifically, The AlCrN-based coated mill presented less fracture resistance. For TiN coated micro end mill, only slight cutting edge chipping occurred. Compared with other types of tools, the AlTiN-based coated micro end mill could maximize tool life, bringing about an integrated cutting edges with the smallest surface roughness. In short, the AlTiN-based coating material is recommended for the micro end mill in the machining of Ti-6Al-4V.

Regenerative Chatter Vibration Occurring in Turning With Different Side Cutting Edge Angles

1995 ◽  
Vol 117 (4) ◽  
pp. 551-558 ◽  
Author(s):  
E. Marui ◽  
M. Hashimoto ◽  
S. Kato
Keyword(s):  
Energy Supply ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Edge ◽  
The Other ◽  
Chatter Vibration ◽  
Regenerative Chatter ◽  
Edge Angle ◽  
Regenerative Effect ◽  
Two Factors

This paper deals with the regenerative chatter vibration occurring in cutting tools with different side cutting edge angles. The occurrence of regenerative chatter vibration of the cutting tool is influenced by two factors, which are closely related to the vibratory energy supply or consumption. One factor is the interference effect between the tool flank and the workpiece. Of course, this factor exists in the primary chatter, too. The other is the regenerative effect. The influence of both factors on the regenerative chatter vibration of cutting tools with different side cutting edge angles is examined experimentally. The vibratory energy supply is simulated, considering the dynamic cutting process. As a result, the property of the regenerative chatter vibration and the influence of the side cutting edge angle on the regenerative chatter vibration are clarified.

COMPARISON OF EXPERIMENTALLY MEASURED AND SIMULATED WORKPIECE AND GRINDING WHEEL TOPOGRAPHY USING A NEW DRESSING MODEL

2016 ◽  
Vol 40 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Abdalslam Darafon ◽  
Andrew Warkentin ◽  
Robert Bauer
Keyword(s):  
Surface Finish ◽  
Metal Removal ◽  
Ground Surface ◽  
Cutting Edge ◽  
Edge Density ◽  
Grinding Wheel ◽  
Workpiece Surface ◽  
Wheel Topography ◽  
Grinding Wheel Topography ◽  
Grinding Conditions

This paper presents a new empirical model of the dressing process in grinding which is then incorporated into a 3D metal removal computer simulator to numerically predict the ground surface of a workpiece as well as the dressed surface of the grinding wheel. The proposed model superimposes a ductile cutting dressing model with a grain fracture model to numerically generate the resulting grinding wheel topography and workpiece surface. Grinding experiments were carried out using “fine”, “medium” and “coarse” dressing conditions to validate both the predicted wheel topography as well as the workpiece surface finish. For the grinding conditions used in this research, it was observed that the proposed dressing model is able to accurately predict the resulting workpiece surface finish for all dressing conditions tested. Furthermore, similar trends were observed between the predicted and experimentally-measured grinding wheel topographies when plotting the cutting edge density, average cutting edge width and average cutting edge spacing as a function of depth for all dressing conditions tested.

Influence of customized cutting edge geometries on the workpiece residual stress in hard turning

2017 ◽  
Vol 232 (12) ◽  
pp. 2132-2139 ◽  
Author(s):  
Carlos EH Ventura ◽  
Bernd Breidenstein ◽  
Berend Denkena
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Hard Turning ◽  
Influence Factors ◽  
Contact Length ◽  
Cutting Edge ◽  
Stress Profile ◽  
Workpiece Surface ◽  
Residual Stress Profile ◽  
Initiation And Propagation

Depending on the intensity of mechanical and thermal loads during hard turning, compressive and/or tensile residual stress can be obtained. However, only compressive residual stress contributes to avoid crack initiation and propagation and increase fatigue life. In order to induce compressive residual stress in the workpiece surface and subsurface, cutting edge geometry is one of the most important influence factors. Taking this into account, the influence of new customized cutting edge geometries on the parameters of a hook-shaped residual stress profile (typical of a hard turning process) is investigated and possible causes for the encountered phenomena are explained. It was found that edge geometries, which provide an increase in contact length between tool and workpiece, lead to higher compressive residual stress in the subsurface and deeper affected zones.

An improved semi-analytical approach for modeling of process damping in orthogonal cutting considering cutting edge radius

2019 ◽  
Vol 234 (3) ◽  
pp. 641-653 ◽  
Author(s):  
Chang Cao ◽  
Xiao-Ming Zhang ◽  
Tao Huang ◽  
Han Ding
Keyword(s):  
Computational Efficiency ◽  
Orthogonal Cutting ◽  
Finite Amplitude ◽  
Cutting Edge ◽  
Workpiece Surface ◽  
Process Damping ◽  
Flank Face ◽  
The Stability ◽  
The Time Domain ◽  
Stability Limits

Process damping generated between the tool flank face and the wavy finish workpiece surface has a non-negligible effect on cutting dynamics and chatter stability, especially at low cutting speeds, resulting in higher stability limits. In modeling of process damping, the calculation of extruded volume is one of the most critical challenges, especially in machining with honed tools due to the complex and time-variable contact condition between the arc cutting edge and the finite amplitude wave surface. In this study, a semi-analytical method with high computational efficiency is proposed to calculate the extruded volume in cutting with honed tools. Based on this method, we construct the stability lobes under the condition of finite vibration amplitude accurately and efficiently, which overcomes the limitation of analytical methods based on the assumption of small amplitude vibrations and the low computational efficiency of numerical method. The predicted cutting stability is verified against both the experimental results and the time-domain simulation results.

Machined Surface Roughness Geometry Model Development on Ultrasonic Vibration Assisted Micromilling with End Mill

2020 ◽  
Vol 846 ◽  
pp. 122-127
Author(s):  
Gandjar Kiswanto ◽  
Yolanda Rudy Johan ◽  
Poly ◽  
Tae Jo Ko
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Cutting Tool ◽  
Model Development ◽  
Cutting Edge ◽  
End Mill ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Geometry Model ◽  
Machined Surface Roughness

Micro products or micro components are commonly used in today’s world. Research around micromanufacture technologies to produce a better product quality has been going on extensively. Ultrasonic vibration assisted micromilling (UVAM) is one of the technologies that can give a better machining qualities over the conventional ones. One of the benefits UVAM can give is reducing the machined surface roughness. The purpose of this paper is to give an idea how vibration assisted micromilling can give a better surface roughness quality. The theoritical surface roughness geometry model is made using MATLAB software. The cutting tool used in the simulation is end mill. There is a feature of the cutting tool called bottom cutting edge angle. This feature will be considered on this paper. The effects of the bottom cutting edge on workpiece machined surface can be looked visually from the simulation. Thus, the effects of cutting process using UVAM on the workpiece surface can be looked as well through the simulation.

Chatter Vibration of Lathe Tools. Part 2: On the Mechanism of Exciting Energy Supply

1983 ◽  
Vol 105 (2) ◽  
pp. 107-113 ◽  
Author(s):  
E. Marui ◽  
S. Ema ◽  
S. Kato
Keyword(s):  
Theoretical Result ◽  
Elastic Deformation ◽  
Energy Supply ◽  
Cutting Edge ◽  
Interference Model ◽  
Experimental Result ◽  
Chatter Vibration ◽  
Different Levels

First, the development of the chatter vibration is observed using several turning tools having various cutting edge configurations and in the conditions in which there are different levels of interference between the flank of the tool and the workpiece. Next, the exciting energy provided by the contact of tool flank and workpiece is calculated using an interference model at the tool flank which includes an elastic deformation of workpiece. This theoretical result agrees qualitatively with the experimental result concerning the development of chatter vibration. The energy-supplying mechanism in primary chatter vibration of a turning tool is clarified by examining the foregoing results collectively.

Calculation of Contact Stresses during Titanium Alloy Cutting

2018 ◽  
Vol 769 ◽  
pp. 364-370
Author(s):  
Victor Kozlov ◽  
Jia Yu Zhang ◽  
Ying Bin Guo ◽  
Sai Kiran Sabavath
Keyword(s):  
Titanium Alloy ◽  
Feed Rate ◽  
Cutting Tool ◽  
Contact Stresses ◽  
Cutting Edge ◽  
Initial Time ◽  
Small Magnitude ◽  
Normal Contact Stress ◽  
Normal Contact ◽  
Flank Surface

The paper presents data about distribution of contact stresses on a rake surface and flank-land of a cutter in free orthogonal turning of a disk made from a titanium alloy (Ti-6Al-2Mo-2Cr). On the cutting edge of the bar blade, there is a normal force Nρ, directed perpendicularly to a transient surface, with a large magnitude of specific linear force qN r= 182.6 N/mm, but the tangential force on the cutting edge Fρis equal to zero. On the rake surface, there are uniformly distributed shear contact stresses with very small magnitude of τ ≈ const ≈ 25 MPa, irrespective of feed rate, which speaks about plastic character of the contact on the rake surface. The greatest normal contact stress on the rake surface σmax≈ 1009 MPa, irrespective of feed rate. The greatest magnitude of normal contact stresses on the flank surface chamfer near the cutting edge σh max= 3400-2200 MPa confirms the hypothesis about recovery of a transient surface sag after separation of a formed element of a chip, and explains increased wear of the cutting tool on the flank surface at initial time. Normal σhand shear τhcontact stresses on the flank surface chamfer are essentially diminish with a distance from the cutting edge. It explains working ability of the cutting tool even at very large wear on the flank surface (hf> 3 mm). Our experimental data allows calculating the components of cutting force and contact stresses on the rake and flank surfaces of cutting tools during titanium alloy (Ti-6Al-2Mo-2Cr) machining.

Experimental investigation into the effect of chatter on surface micro-topography of gears in grinding

2016 ◽  
Vol 231 (2) ◽  
pp. 294-308 ◽  
Author(s):  
Yao Liu ◽  
Xiufeng Wang ◽  
Jing Lin ◽  
Wei Zhao
Keyword(s):  
Surface Topography ◽  
Functional Performance ◽  
Low Frequency ◽  
Work Piece ◽  
Chatter Vibration ◽  
Multi Scale ◽  
3D Surface Topography ◽  
Tooth Flank ◽  
Flank Surface ◽  
Micro Topography

Chatter affects the surface topography and functional performance of work pieces significantly. The surface topography of work pieces is multi-scale, and the characteristics of different levels of the surface topography are closely connected to the different functional performance of the work piece. The relationship between chatter vibration and surface micro-topography is complicated and not specified. By investigating and understanding this relationship clearly, the manufacturing process can be directed to be controlled more actively and accurately, which helps complete the product with expected surface topography and functional performance. This paper aims to reveal the effect of chatter on the surface micro-topography of gears in grinding. Grinding processes considering different machining states and surface topographies of gears under each process were analyzed comprehensively. The following findings were observed. First, chatter causes significant increase of the tooth flank surface roughness in low frequency and increase of the profile roughness, whereas in a different manner in the different gear flank directions. Second, the influence of chatter mainly concentrates on certain frequency bands of the surface topography, and the effect of chatter on the 3D surface topography is within a frequency range. Third, chatter vibration with its multi-frequency-band characteristics shows a multi-scale influence on the work piece surface topography. The possible mechanisms for the formation of these effects were also discussed.

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