Prediction of Chip Back-Flow Angle in Machining With Restricted Contact Grooved Tools

2000 ◽  
Author(s):  
N. Fang ◽  
I. S. Jawahir
Keyword(s):  
Predictive Model ◽  
High Speed ◽  
Experimental Validation ◽  
Chip Thickness ◽  
Interfacial Stress ◽  
Tool Geometry ◽  
Flow Angle ◽  
Back Flow ◽  
Definition Of ◽  
The Given

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

Analytical Prediction of the Chip Back-Flow Angle in Machining With Restricted Contact Grooved Tools

2003 ◽  
Vol 125 (2) ◽  
pp. 210-219 ◽  
Author(s):  
N. Fang ◽  
I. S. Jawahir
Keyword(s):  
High Speed ◽  
Experimental Validation ◽  
Chip Thickness ◽  
Interfacial Stress ◽  
Tool Geometry ◽  
Analytical Prediction ◽  
Flow Angle ◽  
Back Flow ◽  
Definition Of ◽  
The Given

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.

Size Effects in Cutting With a Diamond-Coated Tool

2011 ◽  
Author(s):  
Feng Qin ◽  
Xibing Gong ◽  
Kevin Chou
Keyword(s):  
Residual Stresses ◽  
Size Effect ◽  
Normal Stress ◽  
High Speed ◽  
Chip Thickness ◽  
Tool Geometry ◽  
Uncut Chip Thickness ◽  
Edge Radius ◽  
Coated Tool ◽  
Tool Stresses

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.

scholarly journals Technology improvement of ultrasonic refinement of machinery work surfaces based on phenomenological investigation of cavity formations

2017 ◽  
Vol 2 (1) ◽  
pp. 16-21
Author(s):  
Сергей Сундуков ◽  
Sergey Sundukov ◽  
Равиль Нигметзянов ◽  
Ravil Nigmetzyanov ◽  
Дмитрий Фатюхин ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Acoustic Pressure ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Technology Improvement ◽  
Depth Study ◽  
Definition Of ◽  
The Given ◽  
Small Bubbles

The study of processes based on cavitation use required a clear definition of phenomena arising in liquid at high-frequency oscillation impact upon it. For the in-depth study of the phenomena under investigation in the given work there was used a high-speed video filming. As the analysis of high-speed filming has shown after closing a bubble is divided into many pieces which, in their turn, pulse in-phase. At the same time there is observed a formation of complex bubble formations which are offered to be called clusters (Fig. 3). Bubbles formed under the influence of variable acoustic pressure and located at a small distance from each other combine. Two processes take place simultaneously – bubbles combining (coalescence) and the integration of small bubbles in larger ones under the influence of cohesion forces with the formation of general structures (coagulation). The coalescence is followed with the transition of a system in a state with lower free energy.

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

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Tristan Régnier ◽  
Guillaume Fromentin ◽  
Alain D'Acunto ◽  
José Outeiro ◽  
Bertrand Marcon ◽  
...  
Keyword(s):  
High Speed ◽  
Laser Scanning ◽  
Phenomenological Study ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Experimental Methodology ◽  
Burr Formation ◽  
Tool Geometry ◽  
Exit Burr

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.

scholarly journals Analysis of the hydraulic conditions of the downhole spillway to possibility of the cavitation

2016 ◽  
Vol 4 ◽  
pp. 9-15
Author(s):  
Zimniukov V.A. ◽  
Zborovskaia M.I. ◽  
Zaitsev A.I.
Keyword(s):  
Working Conditions ◽  
High Speed ◽  
High Water ◽  
Safe Operation ◽  
Hydraulic Conditions ◽  
Definition Of ◽  
Speed Mode ◽  
The Given ◽  
Piezometric Pressure

Studying the work of the deep spillway with segment gate, the presence threshold and asymmetric diffuser outlet part with the determination of possibility appearance of cavitation. As a working case is regarded a pass a high water. Identified the causes of occurrence of cavitation in the offtake spillway tract with the definition of high-speed mode, and the study of piezometric pressure in the calculated alignments, based on data obtained by the model scale 1:50 M spillway. As a result of analysis of the data revealed that under the given working conditions cavitation will occur in the presence of any potential exciter in the pressureless part of the spillway. To ensure safe operation of the spillway is necessary to change the construction of the outlet or change the characteristics of the water flow (for example, use aerators).

Influence of Cutting Conditions on Chip Formation in High Speed Milling of Brittle Graphite

2014 ◽  
Vol 633-634 ◽  
pp. 769-772
Author(s):  
Li Zhou ◽  
Cheng Yong Wang ◽  
Wen Hong Li ◽  
Bai Xi Zhu ◽  
Yu Jia Zhai
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Cutting Conditions ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Undeformed Chip Thickness ◽  
Radial Depth

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.

Analytical Predictive Modeling of Serrated Chip Formation in High Speed Machining of 7075-T6 Aluminum Alloy

2004 ◽  
Author(s):  
Ning Fang ◽  
Juhchin Yang ◽  
Nan Liu
Keyword(s):  
Aluminum Alloy ◽  
Chip Formation ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Shear Plane ◽  
Tool Geometry ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Serrated Chip Formation

High speed machining has received increasingly broad applications in various industries, especially in the aircraft and aerospace industry, where a large number of structural frames are machined. Based on Manyindo and Oxley’s descriptive model of serrated chip formation, this paper proposes a new mathematical model for high speed machining of 7075-T6 aluminum alloy. The new model integrates Johnson-Cook’s material model with Oxley’s machining theory and is validated by using the published experimental data. A good agreement between the predicted and experimental degree of chip segmentation is reached. The effects of cutting conditions and tool geometry on the serrated chip geometry, the cutting forces, and the shear-plane angles are quantitatively investigated. The analysis shows that a large undeformed chip thickness, a negative tool rake angle, and a high cutting speed strengthen the degree of chip segmentation in high speed machining.

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