scholarly journals Phenomenological Study of Multivariable Effects on Exit Burr Criteria During Orthogonal Cutting of AlSi Alloys Using Principal Components Analysis

Author(s):  
Tristan Régnier ◽  
Guillaume Fromentin ◽  
Alain D'Acunto ◽  
José Outeiro ◽  
Bertrand Marcon ◽  
...  

During machining, burrs are produced along a part's edges, which can affect a final product lifetime or its efficiency. Moreover, time-consuming and expensive techniques are needed to be applied to remove such burrs. Therefore, companies attempt to reduce burrs formation during machining by manipulating the cutting conditions. This study aims to analyze and quantify the effect of a wide number of parameters on burr formation, resulting from different mechanisms, during orthogonal cutting of AlSi alloys. A highly developed experimental methodology combining high-speed camera recording, laser scanning, and in situ deburring system is used for this study. A statistical analysis is then applied to evaluate relations between controlled parameters and the occurrence of exit burrs morphologies. The results show that the uncut chip thickness influences burr types distribution along the exit edge and chamfer geometry. Among the cutting parameters and tool geometry, tool rake angle is the main parameter affecting burr height. Finally, it is found that none of the burrs geometrical characteristics ranges are piloted by cutting parameters or tool geometry. The assumption of a possible microstructural influence on these outputs is made.

Author(s):  
Seyed Ali Niknam ◽  
Rene Kamguem ◽  
Victor Songmene

The burr formation mechanism and surface quality highly depend on machining conditions. Improper selection of cutting parameters may cause tremendous manufacturing cost and low product quality. Proper selection of cutting parameters which simultaneously minimize burr size and surface roughness is therefore very important, as that would reduce the part finishing cost. This article aims to present an experimental study to evaluate parameters affecting the exit burr size (thickness and height) and surface roughness during milling of 6601-T6 aluminum alloy. Desirability function, Di(x), is then proposed for multiple response optimization. Optimum setting levels of process parameters are determined for simultaneous minimization of surface roughness and exit burr thickness and height. It was found that the changes in feed per tooth and tool geometry and coating have significant effects on variation of Di(x).


Author(s):  
Keith A. Bourne ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor

In an earlier paper, a high-speed microgroove cutting process that makes use of a flexible single-point cutting tool was presented. In this paper, 3D finite element modeling of this cutting process is used to better understand process mechanics. The development of the model, including parameter estimation and validation, is described. Validation experiments show that on average the model predicts side burr height to within 2.8%, chip curl radius to within 4.1%, and chip thickness to within 25.4%. The model is used to examine chip formation, side burr formation, and exit burr formation. Side burr formation is shown to primarily occur ahead of a tool and is caused by expansion of material compressed after starting to flow around a tool rather than becoming part of a chip. Exit burr formation is shown to occur when a thin membrane of material forms ahead of a tool and splits into two side segments and one bottom segment as the tool exits a workpiece.


Author(s):  
Keith A. Bourne ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor

In an earlier paper, a high-speed micro-groove cutting process that makes use of a flexible single-point cutting tool was presented. In this paper, 3D finite element modeling of this cutting process is used to better understand process mechanics. The development of the model, including parameter estimation and validation, is described. Validation experiments show that on average the model predicts side burr height to within 2.8%, chip curl radius to within 4.1%, and chip thickness to within 25.4%. The model is used to examine chip formation, side burr formation, exit burr formation, and the potential for delamination of a workpiece consisting of a thin film on a substrate. Side burr formation is shown to primarily occur ahead of a tool and is caused by expansion of material compressed after starting to flow around a tool rather than becoming part of a chip. Exit burr formation is shown to occur when a thin membrane of material forms ahead of a tool and splits into two side segments and one bottom segment as the tool exits a workpiece. Lastly, examination of the stresses below a workpiece surface shows that film delamination can occur when the depth of a groove cut into a thin film is large relative to the film thickness.


2014 ◽  
Vol 633-634 ◽  
pp. 769-772
Author(s):  
Li Zhou ◽  
Cheng Yong Wang ◽  
Wen Hong Li ◽  
Bai Xi Zhu ◽  
Yu Jia Zhai

Graphite chip formation is important for the understanding of high speed milling of brittle graphite. This paper is aimed to reveal the influence of cutting conditions on the graphite chip formation in high speed milling. The relationship between the maximum undeformed chip thickness and cutting parameters was analyzed, and the influence of cutting parameters, tool geometry and milling patterns on the chip formation of brittle graphite was studied. It is concluded that the transitions of graphite chip formations were highly dependent on the undeformed chip thickness which is decided by the combination setting of feed per tooth and radial depth of cut. Big fractured block chip occurs more easily in up milling than down milling. Tool rake angle influences the chip formation according to the maximum undeformed chip thickness.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


Author(s):  
Felicia Stan ◽  
Daniel Vlad ◽  
Catalin Fetecau

This paper presents an experimental investigation of the cutting forces response during the orthogonal cutting of polytetrafluoroethylene (PTFE) and PTFE-based composites using the Taguchi method. Cutting experiments were conducted using the L27 orthogonal array and the effects of the cutting parameters (feed rate, cutting speed and rake angle) on the cutting force were analyzed using the S/N ratio response and the analysis of variance (ANOVA). Statistical models that correlate the cutting force with process variables were developed using ANOVA and polynomial regression. The variation of the apparent friction coefficient was analyzed with respect to tool geometry and the cutting process. The results indicated that cutting and thrust forces increase with increasing feed rate, and decrease with increasing rake angles from negative to positive values and increasing cutting speed. A power law relationship between the apparent friction coefficient and the normal force exerted by the chip on the tool-rake face was identified, the former decreasing with an increasing normal force.


1999 ◽  
Author(s):  
A. K. Balaji ◽  
I. S. Jawahir

Abstract This paper presents the results of an investigative study on the chip side-curling mechanism and the associated variable tool-chip contact in turning operations. The effect of various cutting and tool geometry parameters such as depth of cut-nose radius ratio, feed, inclination angle, etc. on chip side-curling are established in a hierarchical manner. The importance of variable friction at the tool-chip interface along the developed length of the cutting edge is shown from the experimental observations of the tool-chip contact area using a SEM analysis. The significant influence of the radial cutting force component on the resultant chip side-curl is established using a high speed-filming analysis of comparative experiments in tube and bar turning operations.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 276 ◽  
Author(s):  
Muhammad Asad ◽  
Hassan Ijaz ◽  
Waqas Saleem ◽  
Abdullah Mahfouz ◽  
Zeshan Ahmad ◽  
...  

This contribution presents three-dimensional turning operation simulations exploiting the capabilities of finite element (FE) based software Abaqus/Explicit. Coupled temperature-displacement simulations for orthogonal cutting on an aerospace grade aluminum alloy AA2024-T351 with the conceived numerical model have been performed. Numerically computed results of cutting forces have been substantiated with the experimental data. Research work aims to contribute in comprehension of the end-burr formation process in orthogonal cutting. Multi-physical phenomena like crack propagation, evolution of shear zones (positive and negative), pivot-point appearance, thermal softening, etc., effecting burr formation for varying cutting parameters have been highlighted. Additionally, quantitative predictions of end burr lengths with foot type chip formation on the exit edge of the machined workpiece for various cutting parameters including cutting speed, feed rate, and tool rake angles have been made. Onwards, to investigate the influence of each cutting parameter on burr lengths and to find optimum values of cutting parameters statistical analyses using Taguchi’s design of experiment (DOE) technique and response surface methodology (RSM) have been performed. Investigations show that feed has a major impact, while cutting speed has the least impact in burr formation. Furthermore, it has been found that the early appearance of the pivot-point on the exit edge of the workpiece surface results in larger end-burr lengths. Results of statistical analyses have been successfully correlated with experimental findings in published literature.


Author(s):  
Feng Qin ◽  
Xibing Gong ◽  
Kevin Chou

In machining using a diamond-coated tool, the tool geometry and process parameters have compound effects on the thermal and mechanical states in the tools. For example, decreasing the edge radius tends to increase deposition-induced residual stresses at the tool edge interface. Moreover, changing the uncut chip thickness to a small-value range, comparable or smaller than the edge radius, will involve the so-called size effect. In this study, a developed 2D cutting simulation that incorporates deposition residual stresses was applied to evaluate the size effect, at different cutting speeds, on the tool stresses, tool temperatures, specific cutting energy as well as the interface stresses around a cutting edge. The size effect on the radial normal stress is more noticeable at a low speed. In particular, a large uncut chip thickness has a substantially lower stress. On the other hand, the size effect on the circumferential normal stress is more noticeable at a high speed. At a small uncut chip thickness, the stress is largely compressive.


2003 ◽  
Vol 125 (2) ◽  
pp. 210-219 ◽  
Author(s):  
N. Fang ◽  
I. S. Jawahir

This paper develops a new analytical model to predict the chip back-flow angle in machining with restricted contact grooved tools. The model is derived from a recently established universal slip-line model for machining with restricted contact cutaway tools. A comprehensive definition of the chip back-flow angle is presented first, and based on this, a quantitative analysis of the chip back-flow effect is established for a given set of cutting conditions, tool geometry, and variable tool-chip interfacial stress state. The model also predicts the cutting forces, the chip thickness, and the chip up-curl radius. A full experimental validation of the analytical predictive model involving the use of high speed filming technique is then presented for the chip back-flow angle. This validation provides a range of feasible/prevalent tool-chip interfacial frictional conditions for the given set of input conditions.


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