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Application of ultrasonic excitation to metal forming
processes
M. Rosochowska• Manufacturing Engineering Research Group
Overview
• Objective
• Results
• Approaches
• Findings
• Future work
Objective
• Define the constraints to the application of ultrasonic to metal deformation
Approaches• Definition of processes:
• Experimental Analysis
• Finite Element Analysis
• Process simulation• Equipment design - FE methodology
• Parameters:
• Indentation
• Heading
• Wire flattening
• Back extrusion
• Amplitude of vibrations
• Deformation velocity
• Materials
Indentation Heading
Wire flattening Back extrusion
The Tool
FE results
Punch holder suspension
Vibration mode, Frequency 20kHz
FE analysis of threaded joint between
punch and tool holder
a) excitation a) tightening
Stresses induced by:
FE resultsSimulation of wire-flattening
Stress distributionTool load
V=150mm/s
Experimental resultsIndentation
Steel
0
0.01
0.02
0.03
0.04
200 400 600 800 1000
Punch pressure [MPa]
Sp
ec
ific
in
de
nta
tio
n d
ep
th
DI/
dp
A=0
A=0.01
Aluminium
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 200 400 600
Punch pressure [MPa]
Sp
ec
ific
in
de
nta
tio
n d
ep
th
DI/
dp
A=0
A=10
A=0
A=0.005
A=0.0065
Experimental results
Heading of Aluminium
hH
Do
D
0.00
0.10
0.20
0.30
0.40
0.50
3000 4000 5000 6000 7000 8000
Applied force [N]
Sp
eci
fic
he
ad h
eig
ht
(h/H
)
With Vibration
Without vibrations
Experimental resultsWire-flattening
Copper wire - 1.2 mm
h
do
Cu 0.58 0.42
Al 0.70 0.40
Al-G21 0.63 0.42
r =
0
50
100
150
200
250
300
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1
Die to Die Gap [mm]
Pu
ll-th
rou
gh
Fo
rce
[N
] Static
0.007/L
0.007/D
0.003/L
Experimental resultsBack extrusion
0
200
400
600
800
1000
1200
1400
0 0.5 1 1.5
Punch displacement [mm]
Me
an p
un
ch p
ress
ure
[M
Pa]
Steel
v=0.25mm/s, A=7.2m
1 - v=1mm/s, A=0 4 - 1mm/s, A=4.3m
2 - v=10mm/s, A=2.8m 5 - 0.5mm/s, A=4.6m
3 - v=5mm/s, A=2.8m 6 - 1mm/s, A=8.3m
Aluminium
0.00
100.00
200.00
300.00
400.00
500.00
600.00
0.00 0.50 1.00 1.50 2.00 2.50 3.00
Punch displacement [mm]
Pu
nch
pre
ssu
re [
MP
a] 2 3
1
5
4
6
Findings• Forging force - inversely proportional to excitation
amplitude and directly proportional to deformation velocity
• Excitation applicable to slow deformation-rate processes
• Industrially-significant forming force reduction in wire flattening and back extrusion
Findings
• High-strength work-materials require excessive amounts of energy to excite tools.
• Excitation applicable to processes in which deformation field in the work-material remains in steady-state
• Excitation amplitude limited by the permissible stresses and tolerable thermal changes in tools
Findings
• Application limited to small components
• The process is expensive because tool design is complex and energy consumption relatively large.
• Application limited to low-strength work-materials
Proposed future work
• Evaluate prospects of forming miniature components
• Evaluate prospects of using environmentally- friendly lubricants
• Evaluate machine design requirements for utilisation of tool excitation
