Engineering Metallurgy 1
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Transcript of Engineering Metallurgy 1
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Engineering Metallurgy
Dr.
Mohammed Albaouni
Applied Science Private University
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GaolGaol
The precise discription of the friction in the Finite Element
Simulation of metal forming processes
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1. Some Fundamental Chemistry1. Some Fundamental Chemistry
.
1.1 Atoms, Elements and Compounds
1.2 Chemical Reactions and Equations
1.3 Oxidation and Reduction
1.4 Acids, Bases and Salts
1.5 Atomic Structure
1.6 Chemical Combination and Valence
1.7 Secondary Bonding Forces
1.8 Isotopes1.9 Exercises
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1.1 Atoms, Elements and Compounds1.1 Atoms, Elements and Compounds
Atom:Atom: An atom is the smallest particle of an element that has theAn atom is the smallest particle of an element that has thechemical properties of the element.chemical properties of the element.
Element:Element: pure substances that cannot be decomposed by ordinarypure substances that cannot be decomposed by ordinarymeans to other substancesmeans to other substances
Compound:Compound: are composed of atoms and so can be decomposedare composed of atoms and so can be decomposedto those atoms.to those atoms.
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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ATOMATOM
Atom: An atom is the smallest particle of an element that has the chemical propertiesAtom: An atom is the smallest particle of an element that has the chemical propertiesof the element.of the element.
An atom consists of:An atom consists of:- nucleus (of proton and neutrons)- nucleus (of proton and neutrons)
- electrons in space about the nucleus- electrons in space about the nucleus
the number of electrons is equal to the number of protons.the number of electrons is equal to the number of protons.
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
NucleusNucleus
Electron cloudElectron cloud
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ATOM CompusitionATOM Compusition
Protons (pProtons (p++))
positive electrical chargepositive electrical charge
mass = 1.672623 x 10mass = 1.672623 x 10-24-24 gg
relative mass = 1.007 atomic mass units (amu)relative mass = 1.007 atomic mass units (amu) but we can round to 1but we can round to 1Electrons (eElectrons (e--))
negative electrical chargenegative electrical charge
relative mass = 0.0005 amurelative mass = 0.0005 amu but we can round to 0but we can round to 0Neutrons (nNeutrons (noo))
no electrical chargeno electrical charge
mass = 1.009 amumass = 1.009 amu but we can round to 1but we can round to 1
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Atomic Number, ZAtomic Number, Z
All atoms of the same element have the same number ofAll atoms of the same element have the same number of
protons in the nucleus,protons in the nucleus, ZZ
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
1313AlAl
26.98126.981
Atomic numberAtomic numberAtom symbolAtom symbol
AVERAGE Atomic MassAVERAGE Atomic Mass
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Mass Number, AMass Number, A
C atom with 6 protons and 6 neutrons is the mass standardC atom with 6 protons and 6 neutrons is the mass standard
= 12 atomic mass units= 12 atomic mass units
Mass NumberMass Number(A)(A)= # protons + # neutrons= # protons + # neutrons
NOT on the periodic table(it is the AVERAGE atomic mass on the table)NOT on the periodic table(it is the AVERAGE atomic mass on the table)
A boron atom can haveA boron atom can have
A = 5 p + 5 n = 10 amuA = 5 p + 5 n = 10 amu
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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pure substances that cannot be decomposed by ordinary means to otherpure substances that cannot be decomposed by ordinary means to othersubstances.substances.
The elements, their names, and symbols are given on theThe elements, their names, and symbols are given on thePERIODICPERIODICTABLE.TABLE.
An element can not be changed into a simpler substance by heating or anychemical process
An atom is the basic building block of matter
elements combine in such a way to create millions of compounds Scientists have identified 90 naturally occurring elements, and created about
28 others
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
CHEMICAL ELEMENTS :CHEMICAL ELEMENTS :
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Periodic Table of the ElementPeriodic Table of the Element
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Chemical CompoundsChemical Compounds
CHEMICAL COMPOUNDS are composed of atoms and so can beCHEMICAL COMPOUNDS are composed of atoms and so can bedecomposed to those atoms.decomposed to those atoms.
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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MixturesMixtures
two or more substances that are not chemically combined with each other and can beseparated by physical means. The substances in a mixture retain their individual properties.
Solutions a special kind of mixture where onesubstance dissolves in another.
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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1.2 Chemical Reactions and Equations1.2 Chemical Reactions and Equations
1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Engineering Metallurgy 1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Engineering Metallurgy 1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Engineering Metallurgy 1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Engineering Metallurgy 1. Some Fundamental Chemistry1. Some Fundamental Chemistry
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Engineering Metallurgy 1. Some Fundamental Chemistry1. Some Fundamental Chemistry
OUTLINEOUTLINE
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OUTLINEOUTLINE
1. Introduction
a. Metal Formingb. Finite Element
c. Friction
1. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement1. Summary / Future Work
OUTLINEOUTLINE
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OUTLINEOUTLINE
1. Introduction
a. Metal Formingb. Finite Element
c. Friction
1. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement1. Summary / Future Work
Moti ationMoti ation
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MotivationMotivation
Friction is considered to be a major variable in metal forming and idepends on a multitude of factors, such as contact pressure and relativedisplacement.
To simulate metal forming processes a friction coefficient that is as
accurate as possible becomes necessary.
Classification of manufacturing processesClassification of manufacturing processes
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manufacturing processes
primaryshaping
formingDIN 8582
cutting joiningprocesses
coating heat treatment
compressiveforming
DIN 8583
tensile/compressive
forming
DIN 8584
tensileforming
DIN 8585
bending
DIN 8586
shearforming
DIN 8587
Classification of manufacturing processesClassification of manufacturing processes
Definition of FormingDefinition of Forming
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Metal Forming means the purposeful change in
shape
surface
material properties
of a solid body without changing its weight or chemical composition.
Definition of FormingDefinition of Forming
The roots of Metal Forming are very oldThe roots of Metal Forming are very old
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Forging is one of theoldest work techniques of the
mankind
Already 4000 B. C. pure metalwas worked up through
forging
Since 2500 B.C. copperalloys used (the beginning ofthe bronze age)
Sketch from old Egypt
The roots of Metal Forming are very oldThe roots of Metal Forming are very old
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Advantages of metal formingAdvantages of metal forming
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favourable mechanical properties of the materials,
especially for parts under dynamic loads
high production efficiency with short part production time
high measure- and shape accuracy of the parts within certain
tolerances
high material utilizatione.g. Hot forged parts 75 to 80 %
cold formed parts 85 to 90 %
(for comparison: cutting forming 50 %)
Advantages of metal formingAdvantages of metal forming
Classification of metal forming processes IClassification of metal forming processes I
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Classification can be done according to:
the state of stress in the forming zone
the working temperature or heating before the forming processes:
cold working
hot working
warm working
bulk or sheet forming processes
stationary or transient forming processes
room=
izationrecrystall>
izationrecrystallroom
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Solving methods of Plastomechanics
analytical and numerical methods empirical-analytical methods
elementarytheory slip linetheory
upper
boundmethod
method of
weightedresidual
similaritytheory visio-plasticity
finiteelement
method(FEM)
finitedifference
method(FDM)
boundary-element-method
(BEM)
2.5.1 Solving and test methods, elementary theory
Solving methods of Metal Forming problems (Plastomechanics)Solving methods of Metal Forming problems (Plastomechanics)
OUTLINEOUTLINE
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OUTLINEOUTLINE
1. Introduction
a. Metal Formingb. Finite Element
c. Friction
1. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement1. Summary / Future Work
Why FEM Simulation (1)?Why FEM Simulation (1)?
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y S u at o ( )y S u at o ( )
The main reasons of process simulation are:
reduce time to market
reduce cost of tool development
predict influence of process parameters
reduce productions cost
improve product quality
better understanding of material behaviour
reduce material waste
Why FEM Simulation (2)?Why FEM Simulation (2)?
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y ( )y ( )
while the goals of manufacturing using these techniques are.
accurately predict the material flow
determine the filling of the swage or die
accurate assessment of net shape
predict if laps or other defects exists
determine the stresses, temperatures, and residual stressesin the work piece
determine optimal shape or perform
Finite Element MethodFinite Element MethodFinite Element Method
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The Finite Element Method (FEM) is a mathematical procedure used for the numericalsolving of partial differential equations. It is suitable for dealing with a great number ofphysical and technical tasks such as elastic deformation, plastic strain, temperature field
problems, flow problems etc.. What the finite element method does is to transpose thephysical problem into a problem of variation, area approaches being used for the solving.
The breakthrough of the finite element method began with the introduction of electroniccomputers. The FEM has proved its worth, since it is suitable to almost any structure and theprocedure is numerically stable in many cases. The FEM has also been in use in the formingtechnology to simulate material flows, as well as to calculate stress, strain and temperature
distributions.
triangle element quadrilateral element tetrahedral element hexahedral
element
2.5.5 Solving and test methods,Finite element method
bar element shell element
Processing steps and ideas of FEMProcessing steps and ideas of FEM
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1. Discretisation:
a) in space: simple ,,finite elements
b) in time: discrete time steps
2. Choice of adequate distribution function for the unknown variables withineach element (so called shape function)
3. Setting up a linear equation system by coupling the equations of allelements, considering:
- material properties,
- boundary conditions and
- measures to fulfil the convergence of the simulation
Processing steps and ideas of FEMProcessing steps and ideas of FEM
2.5.5 Solving and test methods,Finite element method
Examples: FEM-simulationsExamples: FEM-simulations
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pp
2.5.5 Solving and test methods,Finite element method
Accurate Simulation Needs (1)Accurate Simulation Needs (1)
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Material Characteristics
Flow curves of workpiece (at differentstrain rates and temperatures)
Ductile damage parameters ofworkpiece
Elastic & fatigue properties of diematerials
Thermal properties of workpiece & diematerial
Boundary conditions
Correct tool geometry
Tool speed
Friction
Heat dissipation coefficients
Heat radiation und transfer
Accurate Simulation Needs (2)Accurate Simulation Needs (2)
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Numerical data
Analysis type Axisymmetric, 3D or plane strain Thermal couplingDiscretization
Element size
Element type
Mesh refinement at sensitive regions
Solution step size & control Convergence limit
Contact parameters
Penalty factors
OUTLINEOUTLINE
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1. Introduction
a. Metal Forming
b. Finite Element
c. Friction
1. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement
1. Summary / Future Work
Friction difinitionFriction difinition
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Friction is a Force that always pushes against an object whenit touches another object
When 2 things are in contact with each other, there will befriction acting between them
Parameters influencing the frictionParameters influencing the friction
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Surface geometry
Layer composition
Lubricant Material pair
Kopp, S. 69/70
Relative velocity
Contact pressure
Temperature
Friction conditions depend on :One now has to distinguishbetween :
Static friction
Sliding friction Roll friction
2.3.1 Boundary conditions, Friction
Friction conditionsFriction conditions
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Metal forming:Mainly mixed-film frictionbecause of the high
contact pressure(usually p > kf)
2.3.1 Boundary conditions, Friction
Friction lawsFriction laws
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Coulomb law:
r= n
r: frictional shear stress
: friction coefficient
n: normal stress
N
R
Rmax = k
N
R m = 1 Rmax = k
Constant friction model r= m*k
r: frictional shear stressm: friction factor
K: shear flow stress
di= 0,5
0 2F c
di= 0,5
0 2
di= 0,5
0 2
di= 0,5
0 2FF cc
Methods to determine the Friction coefficientMethods to determine the Friction coefficient
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M.B. Peterson
N.A. Kravcenko
F
HV
N.A. Kravcenko
R.A. IvanovK. Herold P. Davidkov
K.N. Sevcenko
H.L. Shaw
K.M. Kulkarin
Direkte Messung
s
H.L. Shaw
A.T. Male
J.B. Hawkyard
M. Burgdorf
h
0,2
0,1
0
hu
ho
T
c
F = konst.
h
M.B. Peterson
N.A. Kravcenko
F
HV
F
HV
N.A. Kravcenko
R.A. IvanovK. Herold P. Davidkov
K.N. Sevcenko
H.L. Shaw
K.M. Kulkarin
Direkte Messung
s
H.L. Shaw
A.T. Male
J.B. Hawkyard
M. Burgdorf
h
0,2
0,1
0 h
0,2
0,1
0 h
0,2
0,1
0
hu
ho
hu
ho
TT
cc
F = konst.
h
F = konst.
h
Ring-upsetting testRing-upsetting test
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h0
d0
D0
h0
d0
D0
(h1-h0)/h0
(d
1-
d0
)/d
0
d1
D1
h1
d1
D1
h1
Example:
h = -2,8 mm
d = -2 mm
Conical tube upsetting testConical tube upsetting test
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Beim Kegelrohrstauchversuch wird eine Hohlzylinder-Probe mit einer kegeligen Eindrehung an der Oberseitedurch ein kegelfrmiges Oberwerkzeug axial gestaucht.
Der Neigungswinkel bewirkt, dass bei hheren Reibzahlennoch eine Relativbewegung zwischen Werkstck und
oberem Werk-zeug stattfindet und so einegeometrieabhngige Auswertung auch bei diesem Wert
mglich ist. Je nach erwarteter Reibzahl kann derNeigungswinkel entsprechend variiert werden.
40 mm
40mm
20 mm
40 mm
40mm
20 mm
Wie auch beim Ringstauchversuch wird dieReibungszahl beim Kegelrohtstauchversuch
aus einem Abgleich der an den gestauchtenProben gemessenen Geometrie mit denErgebnissen einer FEM-Simulation ermittelt.
Sinsitivity StudaySinsitivity Studay
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Backward cup drawingBackward cup drawing
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Im ersten Prozess wird ein
Stangenabschnitt aus C 45 von40 mm Durchmesser und 25 mm
Hhe durch Rckwrts-Fliepressen zu einem Napf von
30 mm Innendurch-messer, 50 mmHhe, 5 mm Wand- und
Bodenstrke umgeformt werden. 40 mm
25mm
5 m5 mm
30 mm
40 mm
In meiner Arbeit habe ich die Empfindlichkeit von Ergebnissen derFEM-Simulation von Kaltmassivumformprozessen gegenber der
Variation bzw. Ungenauigkeit der Reibungszahl untersucht. Hierzuwerden die Reibungsbedingungen in den FEM-Simulationen zwei
Prozesse der Kaltmassivumformung variiert.
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Force displacementForce displacement
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Diese Simulationen liefern diese Kraft-Weg-Verlufe. Ausdem Diagramm ist ersichtlich, dass der Kraft-Weg-Verlauf
aus der Simulation mit kontaktdruckabhngigerReibungszahl nicht mit einer konstanten Reibungszahl
nachgebildet werden kann.
5,05,0
Closed die forgingClosed die forging
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Im zweiten Prozess wird ein Rohling auch aus C 45 von
40 mm Durchmesser und 60 mm in einem Gesenk zu dieserGeometrie geschmiedet.
4040
Comperesion of the geometriesComperesion of the geometries
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Dieser Prozess wird zunchst mit dreiunterschiedlichenReibungszahlen (= 0,12; 0,15 und 0,2) und dann mit
kontaktdruckabhngiger Reibungszahl simuliert. Allesonstigen Parameter und Randbedingungen im Modellblieben unverndert. Der Ansatz einer
kontaktdruckabhngigen Reibungszahl liefert eine andereGeometrie, die mit einem konstanten Mittelwert der
Reibungszahl nicht zu erreichen ist
conclusionconclusion
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Aus diesen Simulationen folgt die die Forderung zu prfen,ob tatschlich vergleichsweise groe Variation der
Reibungszahl in Abhngigkeit von Prozessgren auftreten.Diese erfordert zunchst eine entsprechendeVersuchtechnik und Messungen. Je nach Messungen gibt
es dann zwei Mglichkeiten:
Die Abhngigkeit der Reibungszahl von Prozessgren sindso stark, dass dies bercksichtigt werden muss, oder
Die Abhngigkeit der Reibungszahl von Prozessgren sindnicht so stark, dass dies nicht bercksichtigt werden muss.
Methods to determine the frictoin coefficientMethods to determine the frictoin coefficient
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Zur Ermittlung der Reibungszahl fr umformtechnischeAnwendungen gibt es eine Vielzahl von Methoden. Diemeistuntersuchte Methode ist der Ringstauchversuch.
Ring umsetting testRing umsetting test
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Bei diesem Verfahren wird eine ringfrmige Probe zwischen zwei
ebenen Werkzeugen axial gestaucht. Insbesondere der
Innendurchmesser der Probe reagiert sehr empfindlich auf eineVernderung der Reibung whrend der Umformung. Liegt ein
groer Reibwert vor, wird der Innendurchmesser kleiner. Bei
kleinerer Reibung vergrert sich der Innendurchmesser. Aus
einem Abgleich der an den Proben gemessenen Geometrie mitden Ergebnissen einer FEM-Simulation wird die Reibungszahl
ermittelt.
Geometry of the CTU-specimen before and after upsettingGeometry of the CTU-specimen before and after upsetting
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(h1-h0)/h0
(D1
-D0
)/D
0
- The relative displacement is only in the outwards radial direction- There is no sticking zone
- The lower die is grooved, so there is no relative displacement.- Frictional behaviour is only evaluated for the upper contact surface.- The change of the (D) is larger than the change of (d) in the RU test, which
allows more accuracy in determining of .
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Der Ringstauchversuch hat allerdings einige Nachteile. Mitdiesem Versuch kann man z. B die Einflsse von der
Relativgeschwindigkeit oder dem Kontaktdruck auf dieReibungszahl nicht untersuchen. Zur Untersuchung derReibverhltnisse bei Prozessen der Massivumformungwird am IBF daher der Kegelrohrstauchversuch eingesetzt.Dieser Versuch ist eine Weiterentwicklung des
Ringstauchversuchs.
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Fr die Untersuchung des Einflusses vom Kontaktdruck auf
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Fr die Untersuchung des Einflusses vom Kontaktdruck aufdie Reibungszahl wurde der Kegelrohrstauchversuchweiterentwickelt. Allein durch nderung des unteren
Auendurchmessers der Kegelprobe konnte derKontaktdruck zwischen dem oberen Werkzeug und dem
Werkstck erheblich variiert werden.
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Nachdem ich gezeigt habe, dass mit Hilfe desKegelrohrstauchversuches die Einflusse unterschiedlicherProzessbedingungen auf die Reibung untersucht werden
knnen und dass eine eventuelle Abhngigkeit der Reibung
von Prozessbedingungen in der Simulation vonUmformprozessen bercksichtigt werden soll, wurde dieEinflsse unterschiedlicher Prozessbedingungen auf die
Reibungszahl untersucht.
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Aufbauend auf die zuvor beschriebenen
Voruntersuchungen werden nun folgendeEinflussparameter auf die Reibung gezielt experimentell
und numerisch untersucht
Kontaktdruck
Relativgeschwindigkeit
Relativverschiebung und
Rauheit der Kontaktoberflchen
Fr diese Versuche gelten folgende Angaben, wenn nicht
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Fr diese Versuche gelten folgende Angaben, wenn nichtexplizit anderes erwhnt ist:
Probenwerkstoff: C45
Werkzeugwerkstoff: W 500
Rauheitstiefe der Probenoberflche: 0,5 bis 2,2 m
Rauheitstiefe der Werkzeugsoberflche: 0,1-0,3 m
Umformgeschwindigkeit: 1/s
Schmierstoff: Molykote-PasteUmformtemperatur: Raumtemperatur
Kontaktdruck
0606
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Kontaktdruck
0 07
0,08
.06
.06
Bei kleinen Kontaktdrcken trennt eine Schmierstoffschicht dasWerkzeug und das Werkstck voneinander. Damit werden dieAuswirkung der beiden Reibungsmechanismen vermindert. DieReibungszahl steigt bei hohen Kontaktdrcken an, weil derSchmierstoff aus der Wirkfuge verdrngt wird.
Die Reibungszahl steigt mit
zunehmendem Kontaktdruckan. Die wichtigstenReibungsmechanismen sind
Verhaken der Rauheitsspitzenund Adhsionsverbindungen.
Relativgeschwindigkeit 0,04
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g g
0
0,01
0,02
0,03
0,1 1 10 100
Relativgeschwindigkeit in mm/
Reibungszahl
Nach einer Erhhung der Relativgeschwindigkeit (von 0,1 auf
1 mm/s) bleibt die Reibungszahl konstant. Bei grererRelativgeschwindigkeit wurde eine kleinere Reibungszahl ermittelt.Dies ist mit den hydrodynamischen Effekten zu erklren, die sich erstbei hheren Relativgeschwindigkeiten bemerkbar machen. DerVerlauf der Reibungszahl zeigt nur noch eine schwache Abhngigkeit
der Reibungszahl von der Relativgeschwindigkeit im Form einesReibungszahlabfalls mit steigender Relativgeschwindigkeit.
R l ti hi b
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0
0,02
0,04
0,06
0,08
0,1
0 2 4 6 8Relativverschiebung in mm
Reibungszahl
0
200
400
600
800
Kontaktdruckin
N/mm
2
Reibungszahl Kontaktdruck
Relativverschiebung
Aus dem Verlauf der Reibungszahl ber die relative Verschiebungkann keine eindeutige Abhngigkeit der Reibung von derVerschiebung nachgewiesen werden.
F di R h it ibt i
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Fr die Rauheit gibt es eineOptimum. Ist die Rauheit klein, so
dominieren adhsive
Reibungsmechanismen. Beigreren Rauheiten herrschen
deformative Mechanismen vor.
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8th ICTP 2005 in Verona, ItalyOctober 9-13, 20058th ICTP 2005 in Verona, ItalyOctober 9-13, 2005
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Institute of Metal Forming (IBF)
RWTH Aachen University
Germany
Conical Tube-Upsetting Test:
A New Method for Accurate Determinationof the Friction Coefficient
R. Kopp, R. Volles, M. Albaouni, L. Neumann*
Conical Tube-Upsetting Test:
A New Method for Accurate Determinationof the Friction Coefficient
R. Kopp, R. Volles, M. Albaouni, L. Neumann*
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OUTLINEOUTLINE
1. Introduction
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2. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement
1. Summary / Future Work
FEM ModelingFEM Modeling
600
800
1000
MPa
kf
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0
200
400
600
0.0 0.5 1.0
logarithmic strain
flow
stress
Closed-die forging
Rolling with
longitudinalstrip tension
min max
min max
kf
program used: ABAQUS/Standard (elastic/plastic)
element type: axisymmetric quadrilateral (CAX4R)
contact type: surface to surface contact
strain rate: ~1/s
Flow curve of C 45
510
15
510
15
1
51015
21
23
25
20 18 16 14 12 10 8 6 5
3
1
19
Albaouni:Margarita, bitte Beschriftungen auf Arial 18stellen und anordnen.
Albaouni:
Margarita, bitte Beschriftungen auf Arial 18stellen und anordnen.
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Engineering MetallurgyPosition of the contact nodesPosition of the contact nodes
RU testbefore
upsetting
CTU testbeforeupsetting
CTU testafterupsetting(=0.4)
15
10
15
10
1525 22 20 18 16 14 12 10 8 6 4 3 2 1
RU test after upsetting (=0.4)
19
OUTLINEOUTLINE
1. Introduction
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2. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement
1. Summary / Future Work
Distribution of the contact pressure (=0.40)Distribution of the contact pressure (=0.40)h= 50%
h= 25% h= 10% h= 50%
h= 50% h= 25%
h= 25% h= 10%
h= 10%
RU Test CTU Test ( = 25)
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0
500
1000
1500
2000
1 6 11 16
Node No
contactpressureinM
Pa
0
500
1000
1500
2000
1 6 11 16 21Node No.
contactpressureinM
Pa
NoNode No.Node No. NoNoNode No.Node No.Node No.Node No.
RU Test ( )
Distribution of the contact pressure (=0.05)Distribution of the contact pressure (=0.05)
1500
RU Test CTU Test ( = 10)
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0
500
1000
1500
0 5 10 15 20 25
Node No
contactpressurein
MPa
0
500
1000
1500
0 5 10 15 20 25Node No
contactpressureinMPa
h= 50%h= 25% h= 10% h= 50%h= 50%h= 25% h= 25% h= 10% h= 10%
workpiece
tool
Differences in the contact pressureDifferences in the contact pressure
200
300
400
500
600
900
1200
MPa
MPa
h = 25 %h = 10 %
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0
300
600
900
1200
1500
0 0.2 0.4
0
100
200
0 0.2 0.4
0
300
0 0.2 0.4
RU Test CTU Test
pin
pin
pinMPa h = 50 %
OUTLINEOUTLINE
1. Introduction
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2. Finite element modelling
Conical Tube Upsetting (CTU) Test
Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement
1. Summary / Future Work
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Max. difference in the relative displacementMax. difference in the relative displacement
4
4.5
ve
RU Test CTU Test
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0
0.5
1
1.5
22.5
3
3.5
0 0.2 0.4Friction coefficient
Max.difference
inrelativ
displacemen
tinmm
sticking zone appears
OUTLINEOUTLINE
1. Introduction
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2. Finite element modelling
Conical Tube Upsetting (CTU) Test Ring Upsetting (RU) Test
1. Simulation results
Comparison of the contact pressure
Comparison of the relative displacement
1. Summary / Future Work
Ring-upsetting (RU) und conical tube-upsetting (CTU)tests have been compared through simulation.
SummarySummary
2000
p kf MParelative displacement
[mm]
1000
relative displacement
[mm]
0
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(h1-h0)/h0
(D1-
D0
)/D
0