thermomechanical processing for creating bi-metal bearing ... · die forging ! impact extrusion !...
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Spartanburg, South Carolina, June 5-7, 2018
Thermomechanical Processing for Creating Bi-Metal Bearing Bushings
Thermal Processing in Motion
Robert C. Goldstein Bernd-Arno Behrens Anna Chugreeva
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 2 | Thermal Processing in Motion 2018
! Introduction and Motivation
! SFB 1153 Tailored Forming
! Forming Process Design
! Results
! Summary and Outlook
Outline
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 3 | Thermal Processing in Motion 2018
Introduction and Motivation
Automobile Engines
Otto engine (non-charger)
Otto engine (turbocharger)
Diesel engine
Year
Spe
cific
Out
put,
kW/d
m3
Source: Golloch, 2005 Source: Audi AG 1.8 TFSI Engine
! Rising output density
! Locally varying loads
! Conservation of resources
! Energy efficiency
! Integrate different materials into one single bi-material component
! Take advantage of specific characteristics of different materials
Current Trends Solution approaches
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 4 | Thermal Processing in Motion 2018
Introduction and Motivation
Turbine Blade
Dental Implant Generator Shaft
mechanical loading
biocompatible surface roughness little weight
mechanical/tribological loading
mechanical loading
thermal loading
Energy Technology
Piston
thermal/mechanical loading
little weight
Automative Engineering Aerospace Engineering
Drive Shaft Yoke
tribological loading
mechanical loading
Automative Engineering Medical Engineering
Appropriate Material at the Appropriate Location
! Extended functionality of components
! Lightweight construction
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 5 | Thermal Processing in Motion 2018
Outline
! Introduction and Motivation
! SFB 1153 Tailored Forming
! Forming Process Design
! Results
! Summary and Outlook
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 6 | Thermal Processing in Motion 2018
! Die forging ! Impact extrusion ! Cross wedge rolling
Use of combined semi-finished workpieces and thermo-mechanical manufacturing processes to produce hybrid components with locally-adapted properties
Joining Forming Finishing High-performance components with locally-adapted properties
SFB 1153 Tailored Forming
! Profile extrusion ! Deposition welding ! Friction welding
! Machining ! Heat treatment ! Finishing
General Process Chain within the Collaborative Research Centre SFB 1153
! Service life evaluation ! Geometrical inspection ! Damage prediction ! Multiscale modelling
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 7 | Thermal Processing in Motion 2018
SFB 1153 Tailored Forming
Stepped Shaft 1 Coaxial Arrangement
of Materials
Bearing Bushing Bevel Gear
Bi-Material Automotive Parts
Stepped Shaft 2 Sequential Arrangement
of Materials
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 8 | Thermal Processing in Motion 2018
SFB 1153 Tailored Forming
Stepped Shaft 1 Coaxial Arrangement
of Materials
Bearing Bushing Bevel Gear
Bi-Material Automotive Parts
Stepped Shaft 2 Sequential Arrangement
of Materials
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 9 | Thermal Processing in Motion 2018
Outline
! Introduction and Motivation
! SFB 1153 Tailored Forming
! Forming Process Design
! Results
! Summary and Outlook
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 10 | Thermal Processing in Motion 2018
Initial and Final Geometry
Ø 63 mm
Aluminum AA-6082
Steel 20MnCr5 84
mm
Ø 64 mm
Ø 32 mm
71 m
m
Ø 30 mm
Ø 62 mm Ø 44 mm
Ø 86 mm
The bi-metal bearing bushing represents a lightweight concept:
! Combination of steel 20MnCr5 and aluminum 6082
! Coaxially arranged workpieces were designed in accordance with the final geometry
! High performance and wear resistant material on the high loaded bearing surface
! Light aluminum in the structure areas
! Low weight while maintaining high durability and performance
Bi-Material Workpiece Bearing Bushing
Forming Process Design
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 11 | Thermal Processing in Motion 2018
Forming Process Design
Punch
Disc Springs
Closure Plate
Punch Guide
Ejector Stress Ring
Heating Sleeve
Forging Die
Insulation Plate
Forming Tool System
! Precise positioning of the workpiece by an integrated punch guide
! Near-net-shape forging
! Automatic detaching of the forged parts with disc springs’ force
! Inhomogeneous forming temperature (Steel/Aluminium)
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 12 | Thermal Processing in Motion 2018
Forming Process Design
Heating Concept – Induction Coil
! Dissimilar thermal, physical and mechanical properties of steel and aluminum
! Reaching of material specific forming temperatures for both material is required
! Targeted presetting of temperature gradients by induction heating in order to increase the formability
! Maximum temperature of steel is limited due to the melting temperature of aluminum
! Improvement of the heating efficiency by magnetic flux controller
42 m
m 6 m
m 10
mm
1 2 Steel-Aluminum Workpiece
Magnetic Flux Controller
Induction Coil
Position of Thermocouples: 1 - TAluminum 2 - TSteel
Steel-Aluminum Workpiece
Induction Coil
Workpiece Table
Ceramic Tube Around Coil
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 13 | Thermal Processing in Motion 2018
Forming Process Design
Heating Concept – Effect of Magnetic Flux Controller
Steel
Aluminum
Without Alphaform®
With Alphaform®
Heating Parameter Without Alphaform®
With Alphaform®
Output Voltage, V 600 300 Set Voltage, % 60 100 Heating Time, s 60 10
Aluminum R26,5
R19 Steel
0
100
200
300
400
500
600
0 10 20 30 40 50 60 70 80
Temperature Curves
Time, s
Tem
pera
ture
, °C
Measurement Points
Dimensions mm
Outer Diameter Aluminum 62 Outer Diameter Steel 44 Inner Diameter Steel 32
! Using of magnetic flux controller lead to shorter heating time with less power
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 14 | Thermal Processing in Motion 2018
Outline
! Introduction and Motivation
! SFB 1153 Tailored Forming
! Forming Process Design
! Results
! Summary and Outlook
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 15 | Thermal Processing in Motion 2018
Results
Numerical Modelling of the Heating Process
Simulation
Experiment
0
100
200
300
400
500
600
700
800
900
0 20 40 60 80 100
TSteel
TAluminum
Time, s
Tem
pera
ture
, °C
Comparison between Experiment and Simulation with ideal contact
! Both curves equalize at the same temperature
! The total energy input was the same for both cases
! The shrink-fitted workpieces have not perfect contact " higher temperature gradients possible
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 16 | Thermal Processing in Motion 2018
Results
Numerical Modelling of the Heating Process
150
200
250
300
350
400
450
500
550
600
4 6 8 10 12 0
100
200
300
400
500
600
700
800
900
0 5 10 15 20
TSteel
TAluminum
13 s
14 s
12 s
11 s
10 s
Heating time:
Time, s
Tem
pera
ture
, °C
Tem
pera
ture
, °C
Time, s
Line 1: y = 52,56x – 0,5202 Line 2: y = 60,157x – 427,22
Line 1
Line 2
A: Point of contact conditions change A
TSteel
TAluminum
! The aluminum has a higher thermal expansion coefficient compared with steel
! The gap between steel and aluminum grows with increasing temperature
! The heat exchange decreases due to less contact
Experimentally measured temperature curves
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 17 | Thermal Processing in Motion 2018
Results
Numerical Modelling of the Heating Process
! Integration of a thin layer with temperature dependent conduction properties between steel and aluminum in simulation model
! Slight deviations at the beginning and the end of the heating process are caused by thermal lag of the thermocouples
Comparison between Experiment and Simulation with variable power and conductivity of the gap
0
100
200
300
400
500
600
700
800
900
0 5 10 15 20 25 30 Time, s
Tem
pera
ture
, °C
Simulation
Experiment
TSteel
TAluminum
Rad
ius,
mm
0 2 4 6 8 10 12 14 16 18 20 22 24
16
18
20
22
24
26
28
30
32
Time, s
Temperature, °C 850 800
50
750 700 750 600 550 500 450 400 350 300 250 200
100 150
Radial temperature distribution dependent on heating time
Ste
el
Alu
min
um
Heating
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 18 | Thermal Processing in Motion 2018
Results
Numerical Modelling of the Heating Process
300
450
600
750
900
15 20 25 30
Tem
pera
ture
, °C
Radius, mm
a) Heating time 11 s
After heating
After transportation (6s)
300
450
600
750
900
15 20 25 30
Tem
pera
ture
, °C
300
450
600
750
900
15 20 25 30 Te
mpe
ratu
re, °
C
Radius, mm Radius, mm
b) Heating time 13 s c) Heating time 14 s
Steel Aluminum Steel Aluminum Steel Aluminum
R
Radial temperature distribution in bi-metal workpieces
Used for the Forming Tests
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 19 | Thermal Processing in Motion 2018
Results
Experimental Forming Tests
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 20 | Thermal Processing in Motion 2018
Results
Experimental Forming Tests
Heating strategy 1
EN AW-6082
20MnCr5
EN AW-6082
20MnCr5
Intermetallic Phase
Heating time 13 seconds
Transportation time 6 seconds
TSteel Approx. 717 °C
TAluminum Approx. 458 °C
Bonding quality Form-/ Force-closed joint
Heating strategy 2
Heating time 14 seconds
Transportation time 6 seconds
TSteel Approx. 719 °C
TAluminum Approx. 492 °C
Bonding quality Partially
metallurgical bonding
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 21 | Thermal Processing in Motion 2018
Outline
! Introduction and Motivation
! SFB 1153 Tailored Forming
! Forming Process Design
! Results
! Summary and Outlook
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 22 | Thermal Processing in Motion 2018
Outlook
Summary
Summary and outlook
! Forming of dissimilar materials is challenging due to their different material-specific properties
! By using of tailored heating, high forming strains can be achieved in steel-aluminum workpieces
! The forming temperature have the most influence on the resulting bonding quality
Mechanical characterization of the bonding quality by push-out test
For further improving of bonding quality, an optimization of the heating process is required:
! Targeted cooling of aluminum surface during the induction heating (water spray field, water-cooled robot gripper)
! Reduction of the transportation time
! Application of the induction generator with higher power
Pusher Plug
Steel Aluminum
F
Base Plate
Cross section of push-out test arrangement
© Leibniz Universität Hannover, IFUM, Prof. Dr.-Ing. Bernd-Arno Behrens Seite 23 | Thermal Processing in Motion 2018
Thank you for your attention!
The presented results were obtained within the Collaborative Research Centre 1153 ‘‘Process chain to produce hybrid high performance components by Tailored Forming’’. The speaker would like to thank German Research Foundation (DFG) for the financial and organisational support of this project.
www.sfb1153.uni-hannover.de
Contact us!
Robert C. Goldstein rcgoldstein@fluxtrol.com
Anna Chugreeva chugreeva@ifum.uni-hannover.de
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