Friction-based “Injection Clinching
Joining” of Polymer-Metal Structures
A.B. Abibe1,2, J.F. dos Santos1, S.T. Amancio-Filho1,2
Institute of Materials Research, Materials Mechanics, Solid State Joining Processes1, Advanced Polymer-Metal Hybrid Structures2
POLYMERIC STUD
Challenges
POLYMERIC STAKE
PARTNER
MATERIAL
ICJ
Hot air
Motivation

Improvement of staking-based joining technologies (Fig.1)
for transportation industry
Figure 1: a) Concept of staking process – entrapment of two joining partners
through deformation of a stud into a stake.
Cavity filling in ICJ
Ultrasonic
Figure 3: Comparison of state-of-the-art stake geometry with
Scientific challenges

innovative ICJ approach for improved mechanical anchoring.
Lack of understanding and description of the physics of staking:
heat development, microstructural changes, and mechanical
behaviour
Sources: Hahn and Finkeldey 2003, Abibe et al. 2011.
Technological challenges


Combine energy efficiency with short joining cycles (Fig. 2)
Improve surface finishing quality (design of flat stake heads),
while assuring good mechanical performance (Fig. 3)
Tail light of the 2011
Jaguar XF
Bracket assembly at a
fuselage stiffener
Figure 2: Cycle times and heat transfer mechanisms of state-of-the-art staking
Figure 4: Examples of applications of staking-based
technologies.
technologies on transportation industry. Source: HTE
Engineering report 2011.
Local properties and microstructural zones
Results
Development of F-ICJ process
Zone 1
Zone 2
METAL
POLYMER
(a)
(b)
(c)
Base material
Figure 7: a) Microstructure of a F-ICJ joint; b) map of the local mechanical properties over the polymeric stake, obtained by microhardness.
The map shows evidence of two thermomechanically affected zones; c) translation of the microstructural zones to a FEM model.
Global mechanical properties
Figure 5: Steps of the F-ICJ process.
(a) Lap shear tensile testing
(b) Comparison between
experiment and FEM model
(c) Fracture surface analysis
Heat monitoring
(b) Monitoring curve
(a) Thermogram
45
35
1
25
2
Figure 6: a) Infrared snapshot of the stake head after joining; b) Monitoring curve during process (tool
Figure 8: a) Lap shear tensile testing of an F-ICJ joint, and strain distribution in the polymeric plate over test duration; b) experimental
temperature) and after it (stake temperature). Temperature monitoring of the process helps to
validation of the crack nucleation and stress distribution of the FEM model from Figure 7c; c) Fracture surface analysis. The observed
elucidate effects of parameters in heat generation during joining.
micromechanisms show Region 1 as stable crack growth zone, and region 2 as the unstable, fast crack propagation zone.
Summary and Future Work
A new friction-based staking process for hybrid structures has been
developed. A materials science approach is proposed (Fig. 9) for
process development. Mechanical behaviour is described based on
the microstructure and local mechanical properties.
Outlook
Process optimization and statistical modeling
 Understanding of the effects of process on materials
 Models for mechanical performance prediction
Semi-empirical heat input model
 Comprehension of heat development of the process
Subcomponent joining and testing
 Automated joining at RNA gantry machine
 4-point bending tests and strain distribution monitoring
METALLIC
STIFFENER
POLYMERIC
SHEET (SKIN)
Figure 9: Materials science approach for process understanding, relating the
Figure 10: Model of subcomponent specimen for F-ICJ feasibility study. The structure is similar to those of B-columns in cars, or
processing conditions to a generated microstructure, which yields a set of properties.
skin-stringer assemblies in aircrafts.
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Contact: André Abibe, andre.abibe@hzg.de , Phone +49 (0)4152 87-2037