Ultrasonic Joining (U-Joining) of MetalComposites Hybrid Joints
E.E. Feistauer a,1,2, T. Ebel b,3, J.F. dos Santos a,1, S.T. Amancio-Filho a,1,2
Institute of Materials Research, a Materials Mechanics, 1 Solid State Joining Processes, 2 Advanced Polymer-Metal Hybrid Structures / b Metallic Biomaterials, 3Materials Design and Characterisation
A new direct-assembly joining technology
The U-Joining concept
Potential application
 U-Joining: Metal Injection Molding (MIMStruct) + Ultrasonic Welding
 Environmental friendly
 Energy efficient
 Faster in comparison to the state-of-the-art
 Localized heat development
 No solvent, adhesive or additional materials
 Joining by mechanical interlocking due to the surface 3D reinforcement
(metallic pins) and adhesion forces (polymer consolidation)
Figure 1: Potential application for the U-Joining are found in the automotive, aerospace and infrastructure sectors.
Ultrasonic Joining (U-Joining, pat. applic. EU 15163163.7 )
MIMStruct (EP 2 468 436 B1) production of 3dstructured parts
Principles of the process
Phases of the process
Figure 4: Process phases. P1 - Accomplishment of contact between MIMStruct
pins and composite, P2 - Coulomb friction and unsteady state viscous
Figure 2: MIMStruct manufacture route. The manufacture is
based on the metal injection molding technology.
Figure 3: Schematically representation of the U-Joining process. (1) Positioning of joining parts, (2) Application of
dissipation, P3 - Steady state viscous dissipation, P4 - Complete
pins’
ultrasonic vibration and axial force, (3) Softening of polymer by frictional heat at the interface and onset of pin insertion, (4)
penetration and creation of adhesive forces at the joint interface, and P5 -
Polymer consolidation and (5) End of the process and sonotrode retraction.
Joint consolidation.
Results
Microstructural features
3
MIMStruct
4 Pins
Local mechanical properties
4
3
1
TMAZ
2
4
GFPEI
Figure
7: Formation of micromechanical interlocking at the
MIMStruct (3) and pins (4) surface due to the opened porous.
GF-PEI
Figure 5: Cross-sectional view of a 4 pins joints.
Figure 10: Microhardness maps for the 4 pins joints.
2
1
Figure 8: The molten PEI expelled during the
process fills the pin cavities (1). No visual
microstructural changes in the MIMStruct part
(2). Residual porosity = 4.4 ± 0.7%.
Global mechanical properties
2800
Pin-less reference
4 Pins MIMStruct
6 Pins MIMStruct
Heat development
Max. Temperature [°C]
750
675
Max. temp. R1
Max. temp. R2
629
600
525
450
25
375
344
300
Lap Shear Force [N]
2400
2000
1600
1200
800
Overlap area: 19 x 15mm
MIMStruct thickness: 2.85
GFPEI thickness: 6.35
6 pins
400
0
0.0
225
Overlap area: 13 x 15mm
MIMStruct thickness: 2.85
GFPEI thickness: 6.35
4 pins
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Failure location
0.8
Displacement [mm]
150
0
2
4
6
8
10
12
14
16
18
Figure 11: Customized-lap shear tensile testing .
Time [s]
Figure 9: Curves of maximum temperature obtained by infrared thermography.
Figure 12: Fracture surface of a 6-pins U-joint. The failure mechanism combines
shearing of the metallic pins and mixed cohesive-adhesive failure of the composite.
Summary
A new approach to manufacture future damage-tolerant and crash-resistant lightweight alloy/composite hybrid structures has been introduced.
 Preliminary assessment resulted in fast joining cycles (between 1.3 and 1.7 seconds)
 The 3D reinforcement of MIMStruct parts was successfully inserted in the composite by means of ultrasonic energy
 The thermal-mechanical processing does not changes the mechanical properties of the MIMstruct part
 The hybrid joints showed improved lap shear strength and toughness in comparison to pin-less reference joints
Helmholtz-Zentrum Geesthacht • Max-Planck-Straße 1 • 21502 Geesthacht • Germany • Phone /Fax: +49 (0)4152 87-2066 / 2033 • www.hzg.de
Contact: Eduardo E. Feistauer (technical requests), eduardo.feistauer@hzg.de / Prof. Dr. -Ing. Sergio Amancio (group leader), sergio.amancio@hzg.de