scholarly journals Tool wear and spring back analysis in orthogonal machining unidirectional CFRP with respect to tool geometry and fibre orientation

2021 ◽  
Author(s):  
Lukas Seeholzer ◽  
Fabian Kneubühler ◽  
Frank Grossenbacher ◽  
Konrad Wegener
Keyword(s):  
Tool Wear ◽  
Contact Region ◽  
Cutting Edge ◽  
Wear Behaviour ◽  
Tool Geometry ◽  
Spring Back ◽  
Clearance Angle ◽  
Orthogonal Machining ◽  
Process Forces ◽  
Elastic Spring

AbstractMachining abrasive carbon fibre reinforced polymers (CFRP) is characterised by extensive mechanical wear. In consequence, the cutting edge micro-geometry and thus the tool/material contact situation are continuously changing, which affects process forces and machining quality. As a conclusion, a fundamental understanding of the tool wear behaviour and its influencing factors is crucial in order to improve performance and lifetime of cutting tools. This paper focuses on a fundamental tool wear analysis of uncoated tungsten carbide cutting inserts with different combinations of fibre cutting angles and tool geometries. For this purpose, orthogonal machining experiments with unidirectional CFRP material are conducted, where the wear progression of the micro-geometry is investigated by means of five wear parameters lα, lγ, γ*, α*, and bc. For detecting the actual contact zone of the cutting edge and to measure the elastic spring back of the material, the flank face is marked via short pulsed laser processing. Furthermore, the process forces and the wear rate are measured. It is shown that the material loss due to wear clearly varies along the tool’s contact region and is highly dependent on the clearance angle and the fibre cutting angle Φ, while the influence of the tested rake angles is mostly negligible. Especially in machining Φ=30° and Φ=60°, a strong elastic spring back is identified, which is more intense for smaller clearance angles. For all tested configurations, the material’s elastic spring back increases in intensity as wear progresses which, in combination with the decreasing clearance angle, is the main reason for high thrust forces.

Effect of Micro-Textured Tool Parameters on Forces, Stresses, Wear Rate, and Variable Friction in Titanium Alloy Machining

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Kaushalandra Patel ◽  
Guoliang Liu ◽  
Suril R. Shah ◽  
Tuğrul Özel
Keyword(s):  
Titanium Alloy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Edge ◽  
Tool Geometry ◽  
Texture Parameters ◽  
Variable Nature ◽  
Variable Friction

Abstract Micro-textures applied to cutting tool surfaces provide certain advantages such as reducing tool forces, stresses, and temperature hence overall friction between the tool–chip contact and improving chip adherence and associated tool wear. This study explores the effect of micro-texture geometry parameters fabricated on the rake face of tungsten carbide inserts that were tested in dry turning titanium alloy Ti-6Al-4V. The effects of micro-texture geometry on the cutting forces, tool stresses, tool temperatures, tool wear rate, and variable friction coefficient were studied with 3D finite element (FE) simulations. The simulation model was validated comparing cutting forces predicted and measured. The results indicated some effects of micro-textured tool geometry parameters being significant and others are not as significant. The experiments reveal that the effects of micro-groove width, depth, and distance from cutting edge are found to be significant on cutting forces, but the spacing is not as much. The effect of increasing feed rate on cutting force and tool wear was significant and suppressed the advantages offered by micro-grooved texture tool geometry. The simulation results indicate that the effect of micro-texture parameters such as groove depth and distance from cutting edge is significant on tool temperature and wear rate. The variable nature of friction coefficient was emphasized and represented as functions of state variables such as normal stress and local temperature as well as micro-texture parameters.

THEORETICAL ANALYSIS OF PRODUCTIVITY IN DIFFERENT VARIANTS OF OPTIMIZATION OF CUTTING SPEED IN TURNING

2020 ◽  
pp. 7-13
Author(s):  
V. F. Bezyazychzny ◽  
A. V. Kordyukov
Keyword(s):  
Tool Wear ◽  
Production Cost ◽  
Cutting Tool ◽  
Operating Cost ◽  
Cutting Speed ◽  
Labor Cost ◽  
Cutting Edge ◽  
Tool Geometry ◽  
Work Piece ◽  
Cutting Tool Wear

Analysis and comparison is presented as to processing performance levels with cutting speeds providing various optimization criteria: minimal cutting tool wear, minimal production cost and maximal cutting performance. It has been established that during machining at the cutting speed corresponding to the minimal cutting tool wear performance is close to the level of productivity when machining at the cutting speed corresponding to the minimal production cost. Results of calculations allow estimating both the performance value and the machinability level of different materials in terms of strength, not only in quality, but also in quantity. This assessment is made subject to the physical and mechanical properties of the work piece and the tool materials, the cutting mode (cutting speed and depth, feed), the tool geometry (cutter tip radius in the plan, cutting edge corner radius, face and clearance angles, major and minor cutting edge angles), as well as the economic performance of cutting (cutting time, cost of machine operation and labor cost, cutting tool operating cost).

The Role of Tool Geometry and Process Parameters during Fly Shearing in Hot Rolling of Steel

2014 ◽  
Vol 966-967 ◽  
pp. 184-195
Author(s):  
Hector Torres ◽  
Markus Varga ◽  
Dieter Horwatitsch ◽  
Karl Adam ◽  
Manel Rodríguez Ripoll
Keyword(s):  
Tool Wear ◽  
Process Parameters ◽  
Hot Rolling ◽  
Metal Forming ◽  
Element Model ◽  
Operating Conditions ◽  
Cutting Edge ◽  
Tool Geometry ◽  
Optimum Process

Sheet metal shearing takes place immediately after hot rolling of steel. Due to the extreme operating conditions, flying shear blades suffer from severe wear and need frequent repair, significantly increasing the maintenance costs for steel producers. In order to optimise the shearing process and increase the tool lifetime, a finite element model was applied for performing a systematic variation of the blade geometry and process parameters. In the model, friction is taken into account by implementing a hybrid friction equation, which is suitable for the simulation of metal forming processes. Tool geometry and process parameters such as the vertical overlapping between the two shearing blades were varied in the simulation, in order to identify optimum process parameters. The results obtained show in particular that the variation of the vertical overlapping between both blades has a limited influence on the maximum calculated stresses, leading to the assumption that no significant changes in tool wear may be achieved by modifying it. On the other hand, it was found that higher cutting edge radii lead to significantly lower stresses for both flying shear blades, thus suggesting the possibility of decreasing tool wear through increasing values of the cutting edge radius.

Influence of Cutting Parameters and Tool Geometry on Thrust Force Behavior in Drilling Ti6Al4V

2016 ◽  
Vol 862 ◽  
pp. 3-10
Author(s):  
Marek Vrabeľ ◽  
Ildikó Maňková ◽  
Peter Ižol ◽  
Mária Franková ◽  
Miroslav Paľo
Keyword(s):  
Thrust Force ◽  
Influencing Factor ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Cutting Edge ◽  
Tool Geometry ◽  
Clearance Angle ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Titanium Alloy Ti6al4v

Titanium alloy Ti6Al4V represents one of the most frequently used alloys in medical as well as in aerospace industry and is considered as a difficult to cut material. In this paper, cutting experiments within throughput drilling were carried out under the varying cutting speed, feed and tool geometry (cutting edge radius and clearance angle). The effects of cutting speed feed and tool geometry on thrust force in drilling Ti6Al4V alloy were investigated applying design of experiment (DoE) according to Taguchi plan L16. The effect of above mentioned parameters was investigated through analysis of the S/N ratios (smaller is better) and ANOVA analysis. All analyses were performed using statistical software Minitab and Matlab. In the case of thrust force, the feed is the main influencing factor, followed by cutting speed, cutting edge radius and clearance angle.

scholarly journals Experimental Study of tool Wear Mechanisms in Conventional and High Pressure Coolant Assisted Machining of Titanium Alloy Ti17

2013 ◽  
Vol 554-557 ◽  
pp. 1961-1966 ◽  
Author(s):  
Yessine Ayed ◽  
Guenael Germain ◽  
Amine Ammar ◽  
Benoit Furet
Keyword(s):  
High Pressure ◽  
Titanium Alloy ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
Wear Mechanisms ◽  
Cutting Forces ◽  
Cutting Edge ◽  
Rake Face ◽  
High Pressure Coolant

Titanium alloys are known for their excellent mechanical properties, especially at high temperature. But this specificity of titanium alloys can cause high cutting forces as well as a significant release of heat that may entail a rapid wear of the cutting tool. To cope with these problems, research has been taken in several directions. One of these is the development of assistances for machining. In this study, we investigate the high pressure coolant assisted machining of titanium alloy Ti17. High pressure coolant consists of projecting a jet of water between the rake face of the tool and the chip. The efficiency of the process depends on the choice of the operating parameters of machining and the parameters of the water jet such as its pressure and its diameter. The use of this type of assistance improves chip breaking and increases tool life. Indeed, the machining of titanium alloys is generally accompanied by rapid wear of cutting tools, especially in rough machining. The work done focuses on the wear of uncoated tungsten carbide tools during machining of Ti17. Rough and finish machining in conventional and in high pressure coolant assistance conditions were tested. Different techniques were used in order to explain the mechanisms of wear. These tests are accompanied by measurement of cutting forces, surface roughness and tool wear. The Energy-dispersive X-ray spectroscopy (EDS) analysis technique made it possible to draw the distribution maps of alloying elements on the tool rake face. An area of material deposition on the rake face, characterized by a high concentration of titanium, was noticed. The width of this area and the concentration of titanium decreases in proportion with the increasing pressure of the coolant. The study showed that the wear mechanisms with and without high pressure coolant assistance are different. In fact, in the condition of conventional machining, temperature in the cutting zone becomes very high and, with lack of lubrication, the cutting edge deforms plastically and eventually collapses quickly. By contrast, in high pressure coolant assisted machining, this problem disappears and flank wear (VB) is stabilized at high pressure. The sudden rupture of the cutting edge observed under these conditions is due to the propagation of a notch and to the crater wear that appears at high pressure. Moreover, in rough condition, high pressure assistance made it possible to increase tool life by up to 400%.

Detektion von Schneidkantenversatz und Rautiefe/Surface quality and cutting edge offset detection

2021 ◽  
Vol 111 (11-12) ◽  
pp. 803-806
Author(s):  
Dominik Hasselder ◽  
Eckart Uhlmann
Keyword(s):  
Tool Wear ◽  
Austenitic Steel ◽  
Surface Topography ◽  
Surface Quality ◽  
Academic Research ◽  
Cutting Edge ◽  
Geometrical Parameters ◽  
Dry Turning ◽  
Nominal Diameter

Bei Drehbearbeitung auftretender Verschleiß am Werkzeug ist seit Jahrzehnten Gegenstand der Forschung, denn er beeinflusst die Oberflächengüte und den resultierenden Durchmesser des Werkstücks. Durch die gezielte Platzierung eines Triangulationssensors lassen sich Einflüsse dieser Art detektieren. In Zerspanungsuntersuchungen bei der Bearbeitung des austenitischen Stahls 1.4301 ohne Kühlmedium konnte gezeigt werden, dass der verschleißbedingte Durchmesserfehler und die hergestellte Oberflächentopografie prozesssicher messbar sind.   Tool wear and its detection has been part of academic research for decades. It may result in varying surface quality and is a potential cause of insufficient nominal diameter in turning. Mounting a triangulation laser on a turning tool allows for detecting variations in geometrical parameters of the workpiece. Also, when dry turning the austenitic steel 1.4301 it is possible to continuously detect the resulting surface topography and the discrepancy in the manufactured diameter.

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