Tool Load Sensitivity Against Multidimensional Process Influences in Microblanking of Copper Foils With Silicon Punches

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Sven Hildering ◽  
Markus Michalski ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Tool Life ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Behavior ◽  
Fe Model ◽  
Transfer Of Knowledge ◽  
Test Rig ◽  
Tensile Stresses ◽  
Copper Foils ◽  
Process Behavior

The continuous trend toward miniaturization of metallic microparts of high quality at low costs results in the need of appropriate production methods. Mechanical manufacturing processes like forming and blanking meet these demands. One major challenge for the application of them are the so-called size effects. Especially, the downsizing of the required manufacturing tools and adequate positioning cause higher effort with increasing miniaturization. One promising approach for downsizing of tools is the transfer of knowledge from microsystems technology. This study shows the process behavior of etched silicon punches in microblanking operations. For the application as tool material especially, the brittle material behavior and sensitivity against tensile stresses have to be considered. These mechanical loads favor wear in form of cracks and breaks at the cutting edge of the punch and thus decreasing tool life. In a special test rig these wear phenomena were observed in microblanking of copper foils. Although, high positioning accuracy between tools and workpiece can be assured within this test rig, scatter of tool life is observable. Therefore, a finite element (FE) analysis of the tool load in the microblanking process with special respect to tensile stresses was performed. Within the 3D FE model multidimensional positioning errors like tilting between punch and die were integrated. Their influence on the tool load in form of increasing tensile stresses is evaluated with respect to the type and magnitude of positioning error and verified by experimental results concerning wear. Furthermore, the effect of small outbreaks at the cutting edge on the process behavior and tool load is analyzed.

Tool Load Sensitivity Against Multidimensional Process Influences in Microblanking of Thin Metal Foils With Silicon Punches

2015 ◽  
Author(s):  
Sven Hildering ◽  
Markus Michalski ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Finite Element ◽  
Tool Life ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Behavior ◽  
Transfer Of Knowledge ◽  
Test Rig ◽  
Element Analysis ◽  
Tensile Stresses ◽  
Process Behavior

The continuous trend towards miniaturization of metallic micro parts of high quality at low costs results in the need of appropriate production methods. Mechanical manufacturing processes like forming and blanking meet these demands. One major challenge for the application of them are so called size effects. Especially the downsizing of the required manufacturing tools and adequate positioning causes higher effort with increasing miniaturization. One promising approach for downsizing of tools is the transfer of knowledge from microsystems technology. This study shows the process behavior of etched silicon punches in microblanking operations. For the application as tool material especially the brittle material behavior and sensitivity against tensile stresses have to be considered. These mechanical loads favor wear in form of cracks and breaks at the cutting edge of the punch and decrease tool life. In a special test rig these wear phenomena were observed in microblanking of copper foils. Although high positioning accuracy between tools and workpiece can be assured within this test rig, scatter of tool life is observable. Therefore, a finite element analysis of the tool load in the microblanking process with special respect to tensile stresses was performed. Within the 3D finite element model multidimensional positioning errors like tilting between punch and die were integrated. Their influence on the tool load in form of increasing tensile stresses is evaluated with respect to the type and magnitude of positioning error. Furthermore, the effects of small outbreaks at the cutting edge on the process behavior and tool load are analyzed.

Development and manufacturing of customized milling cutters for individual tool-making industry

2017 ◽  
Vol 1 (82) ◽  
pp. 26-32
Author(s):  
J. Kopač ◽  
F. Pušavec
Keyword(s):  
Tool Wear ◽  
Tool Life ◽  
End Milling ◽  
Tool Material ◽  
Rake Angle ◽  
Cutting Edge ◽  
Cutting Edge Radius ◽  
Edge Radius ◽  
Milling Tools ◽  
Material Cutting

Purpose: Purpose of this paper is to present results obtained during developing new cutting tools for individual tool industry. The aim of the research was to develop customized ball end milling tools with longer tool-life. Design/methodology/approach: to this study of development of new tools was over four successive sets of experiments, where the tool material, cutting edge preparation (cutting edge radius), rake angle and coating were selected for achieving longer tool-life. Tool-life was monitored over measuring tool wear on the flank face of the tool; maximum allowed tool wear was set to VB = 0.3 mm. Findings: of this study are showing that with right combination of the tool material, cutting edge radius, rake angle and appropriate coating, tool-life can be prolonged significant. Research (and practical) implications: implications are reflected in the substituting of all used milling tools from renowned manufacturers with these newly developed tools in this tool industry. Originality/value: of this paper is visible over significant improvement in tool-life of milling tools, especially for the company who will be using these tools in their production.

Plastic Deformation in Microtomed Sections

1971 ◽  
Vol 29 ◽  
pp. 458-459
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Applied Stress ◽  
Elastic Strain ◽  
High Strain ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Structure ◽  
Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

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%.

Drehen von ausferritischem Gusseisen*/Turning of austempered ductile iron – Impact of inhomogeneous cutting edge geometry on wear mechanism and machining result

2018 ◽  
Vol 108 (10) ◽  
pp. 736-742
Author(s):  
J. Hartig ◽  
B. Kirsch ◽  
J. Aurich
Keyword(s):  
Tungsten Carbide ◽  
Tool Life ◽  
Wear Mechanism ◽  
Ductile Iron ◽  
Cutting Edge ◽  
Machining Process ◽  
Austempered Ductile Iron ◽  
Machining Performance ◽  
Edge Geometry ◽  
Homogeneous Preparation

Mit Schneidkantenpräparation kann das Werkzeug im Zerspanprozess an die Bearbeitungsaufgabe angepasst werden. Homogene Präparationen können dabei entweder auf hohe Belastungen des Werkzeugs oder ein optimiertes Bearbeitungsergebnis im Sinne der Oberfläche ausgelegt werden. In diesem Beitrag wurden die Schneidkanten von Hartmetall-Wendeschneidplatten unterschiedlich inhomogen präpariert, um den unterschiedlichen Anforderungen entlang des Eingriffs Rechnung zu tragen. Neben der Werkzeugstandzeit wurde das Prozessergebnis beim Außenlängs-Runddrehen von ausferritischem Gusseisen (ADI) 900 untersucht.   The preparation of cutting edges allows for tools to be tailored to the machining process. A homogeneous preparation can either be designed for high loads in the machining process or an optimized machining result on the surface. In this article, the cutting edges of tungsten carbide indexable inserts were prepared inhomogeneously and thus individually matched to the machining task. Tool life and machining performance while turning austempered ductile iron (ADI) 900 were investigated.

Kantenpräparation durch Formschleifprozesse*/Cutting edge preparation by form grinding

2017 ◽  
Vol 107 (06) ◽  
pp. 453-460
Author(s):  
E. Prof. Uhlmann ◽  
J. Bruckhoff
Keyword(s):  
Tool Life ◽  
Cutting Tools ◽  
Cutting Edge ◽  
Grinding Processes ◽  
Form Grinding ◽  
Cutting Edge Preparation ◽  
Edge Preparation

Angesichts steigender Anforderungen an Zerspanwerkzeuge nimmt die Schneidkantenpräparation einen immer größer werdenden Stellenwert ein, da sich so die Standzeit von Zerspanwerkzeugen erhöhen lässt. Die bisher eingesetzten Präparationsverfahren eignen sich meist nur für einfache Verrundungen an der Schneidkante. In umfangreichen Untersuchungen wurde die Eignung von Formschleifprozessen zur Herstellung definierter Schneidkantenmikrogeometrien anhand von Arbeitsergebnissen analysiert.   Due to increasing demands on cutting tools cutting edge preparation has a high priority because it influences the tool life. Current cutting edge preparation processes can only generate simple roundings on the cutting edge. By extensive investigations the suitability of form grinding processes for the production of defined microgeometries on the cutting edge was analysed.

Standzeitoptimierung von Kreissägewerkzeugen/Optimization of the tool life of circular saw blades

2021 ◽  
Vol 111 (11-12) ◽  
pp. 833-839
Author(s):  
Kolb Moritz ◽  
Tim Mayer ◽  
Nico Rasenberger
Keyword(s):  
Service Life ◽  
Tool Life ◽  
Model Test ◽  
Wear Behavior ◽  
Cutting Edge ◽  
Circular Saw ◽  
Single Tooth ◽  
Cutting Edge Preparation ◽  
Saw Blade ◽  
Edge Preparation

Dieser Beitrag beschreibt, wie sich die Standzeit von Kreissägeblättern durch Schneidkantenpräparation gezielt beeinflussen lässt. Hierfür wurden zunächst einzelne Segmente aus einem Sägeblatt herausgetrennt und Einzahnproben mit variierenden Schneidenmikrogeometrien mittels Bürstspanen präpariert. Anschließend wurde das Einsatz- und Verschleißverhalten der zuvor hergestellten Proben in einem Kreissäge-Modellversuch untersucht.   This article describes how the service life of circular saw blades can be specifically influenced by cutting edge preparation. For this purpose, individual segments were first cut out of a saw blade. These single-tooth specimens with varying cutting edge microgeometries were prepared by abrasive brushing. Then the usage and wear behavior of the previously produced samples was investigated in a circular saw model test.

scholarly journals Numerical Modeling and Experimental Behavior of Closed-Cell Aluminum Foam Fabricated by the Gas Blowing Method under Compressive Loading

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1582 ◽  
Author(s):  
Varun Sharma ◽  
Fatima Zivic ◽  
Nenad Grujovic ◽  
Norbert Babcsan ◽  
Judith Babcsan
Keyword(s):  
Numerical Modeling ◽  
Compressive Loading ◽  
Material Behavior ◽  
Small Cells ◽  
Uniaxial Compression Test ◽  
Average Cell ◽  
Tensile Stresses ◽  
Closed Cell ◽  
Gas Blowing ◽  
Over The Top

This paper deals with the experimental and numerical study of closed-cell aluminum-based foam under compressive loading. Experimental samples were produced by the gas blowing method. Foam samples had an average cell size of around 1 mm, with sizes in the range 0.5–5 mm, and foam density of 0.6 g/cm3. Foam samples were subjected to a uniaxial compression test, at a displacement rate of 0.001 mm/s. Load and stress were monitored as the functions of extension and strain, respectively. For numerical modeling, CT scan images of experimental samples were used to create a volume model. Solid 3D quadratic tetrahedron mesh with TETRA 10-node elements was applied, with isotropic material behavior. A nonlinear static test with an elasto-plastic model was used in the numerical simulation, with von Mises criteria, and strain was kept below 10% by the software. Uniform compressive loading was set up over the top sample surface, in the y-axis direction only. Experimental tests showed that a 90 kN load produced complete failure of the sample, and three zones were exhibited: an elastic region, a rather uniform plateau region (around 23 MPa) and a densification region that started around 35 MPa. Yielding, or collapse stress, was achieved around 20 MPa. The densification region and a rapid rise in stress began at around 52% of sample deformation. The numerical model showed both compressive and tensile stresses within the complex stress field, indicating that shear also had a prominent role. Mainly compressive stresses were exhibited in the zones of the larger cells, whereas tensile stresses occurred in zones with an increased number of small cells and thin cell walls.

Investigations on Three-Roll Bending of Plain Tubular Components

2009 ◽  
Vol 410-411 ◽  
pp. 325-334 ◽  
Author(s):  
Marion Merklein ◽  
Hinnerk Hagenah ◽  
Massimo Cojutti
Keyword(s):  
Material Behavior ◽  
Fe Model ◽  
Forming Process ◽  
Widespread Application ◽  
Numerical Investigations ◽  
Industrial Sectors ◽  
Roll Bending ◽  
First Results ◽  
Bending Radius ◽  
High Flexibility

Bent metal tubes find a widespread application in many industrial sectors. Among different bending processes developed for the manufacturing of these components, three-roll bending is characterized by a high flexibility, as only one toolkit per tube diameter is necessary to form the required bending radius. In this type of forming process the part geometry is obtained by means of a relative movement of the die (setting roll) towards the fixed tools (bending and holding roll) with simultaneous feeding of the tube. This study describes the FE-model developed for the three-roll bending and presents first results of numerical investigations conducted on steel tubes made of carbon steel St37. By the FE-analysis great attention is paid on the modeling of the stiffness of the tool, on the description of the kinematics of the setting roll as well as on the characterization of the material behavior for the simulation. The results of the numerical investigations are compared with experiments conducted with a CNC-bending machine available at the Chair of Manufacturing Technology of the University of Erlangen. As a main criterion for the validation of the FE-model the radius of the tube at the extrados and the bending angle are chosen. The geometry of the part is measured by means of both optical and tactile measuring devices.

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