Friction press joining of dissimilar materials: A novel concept to improve the joint strength

2019 ◽  
Author(s):  
Stefan P. Meyer ◽  
Christoph Wunderling ◽  
Michael F. Zaeh
Keyword(s):  
Joint Strength ◽  
Dissimilar Materials ◽  
Friction Press ◽  
Novel Concept

Joining Processes by Plastic Deformation

2014 ◽  
Vol 966-967 ◽  
pp. 29-47 ◽  
Author(s):  
Kenichiro Mori
Keyword(s):  
Plastic Deformation ◽  
Joint Strength ◽  
State Of The Art ◽  
Dissimilar Materials ◽  
Environmental Safety ◽  
Cold Welding ◽  
Friction Stir ◽  
Mechanical Parts ◽  
Mechanical Clinching ◽  
Improved Accuracy

As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportunities to design new products through joining dissimilar materials. This paper aims to provide an overview of the state of the art in such joining processes, including cold welding, friction stir welding, joining by forming, self-pierce riveting and mechanical clinching. The paper includes description of the mechanism of joint formation, joint strength and applicability.

Influence of Tool Wear on the Load-Bearing Capacity of Shear-Clinched Joints

2020 ◽  
Vol 404 ◽  
pp. 3-10
Author(s):  
Sebastian Wiesenmayer ◽  
Marion Merklein
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Bearing Capacity ◽  
Joint Strength ◽  
Tensile Load ◽  
Dissimilar Materials ◽  
High Strength ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Comparable Level

Shear-clinching allows the joining by forming of dissimilar materials with high differences between their mechanical properties without additional fasteners. Since the lower joining partner is indirectly shear cut during the process, even ultra-high strength materials can be joined. However, the cutting of the high-strength materials as well as the extrusion of the upper joining partner leads to high process forces and therefore to high tool loads. This applies in particular for the die, which is highly stressed during the cutting phase and therefore plastically deformed. Within the scope of this work, the influence of the occurring wear on the formation of the joint and its load-bearing capacity is analyzed for a scope of 500 strokes. For this purpose, press hardened 22MnB5 is used as lower joining partner. Its high strength leads to the plastic deformation of the cutting edge, which increases within the first 200 strokes. Afterwards only minor changes occur. Yet, no effect of the occurring wear on the joint formation and the joint strength, which was tested under shear and tensile load, could be determined. Functioning joints could still be produced for more than 500 strokes as the load-bearing capacity remained on a comparable level.

scholarly journals Analysis of Failure-Mode Dependent Joint Strength in Hole Clinching from the Aspects of Geometrical Interlocking Parameters

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1020 ◽  
Author(s):  
Chan-Joo Lee ◽  
Guo Shen ◽  
Byung-Min Kim ◽  
Francesco Lambiase ◽  
Dae-Cheol Ko
Keyword(s):  
Failure Mode ◽  
Joint Strength ◽  
Analytical Approach ◽  
Failure Modes ◽  
Failure Process ◽  
Dissimilar Materials ◽  
Maximum Error ◽  
Element Analysis ◽  
Practical Applications ◽  
Mechanical Methods

The hole-clinching process is one of the mechanical methods for joining dissimilar materials, such as aluminum alloy with advanced high-strength steel, hot-pressed steel, and carbon fiber reinforced plastics, employing forming technology-based methods. In joint design, the analysis of the failure-mode dependent joint strength is a crucial step in achieving structural performance for practical applications. In this study, the influence of the geometrical interlocking parameters on the failure-mode dependent joint strength was investigated in order to design the geometrical interlocking shape of the hole-clinched joint to achieve a target joint strength. Moreover, the failure process of the hole-clinched joint under pullout loading condition was studied to determine the geometrical interlocking parameters that affect joint strength. Based on the results of the finite element analysis, an analytical approach for the failure-mode dependent joint strength was proposed to predict the strength of the hole-clinched joint. In addition, the proposed analytical approach was applied to the hole-clinching process with dissimilar materials. Its effectiveness was then verified using the cross-tension test. Accordingly, it was found that it was possible to predict the failure modes and joint strength with a maximum error of 7.8%.

scholarly journals Experimental Study on Joining by Forming of HCT590X + Z and EN-AW 6014 Sheets Using Cold Extruded Pin Structures

2021 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
David Römisch ◽  
Martin Kraus ◽  
Marion Merklein
Keyword(s):  
Joint Strength ◽  
Dissimilar Materials ◽  
High Strength ◽  
Linear Increase ◽  
Cold Extrusion ◽  
Manufacturing Processes ◽  
Average Height ◽  
Tensile Shear ◽  
Material Systems ◽  
The Right

Due to stricter emission targets in the mobility sector and the resulting trend towards lightweight construction in order to reduce weight and consequently emissions, multi-material systems that allow a material to be placed in the right quantity and in the right place are becoming increasingly important. One major challenge that is holding back the rapid and widespread use of multi-material systems is the lack of adequate joining processes that are suitable for joining dissimilar materials. Joining processes without auxiliary elements have the advantage of a reduced assembly effort and no additional added weight. Conventional joining processes without auxiliary elements, such as welding, clinching, or the use of adhesives, reach their limits due to different mechanical properties and chemical incompatibilities. A process with potential in the field of joining dissimilar materials is joining without an auxiliary element using pin structures. However, current pin manufacturing processes are mostly time-consuming or can only be integrated barely into existing industrial manufacturing processes due to their specific properties. For this reason, the present work investigates the production of single- and multi-pin structures from high-strength dual-phase steel HCT590X + Z (DP600, t0 = 1.5 mm) by cold extrusion directly out of the sheet metal. These structures are subsequently joined with an aluminium sheet (EN AW-6014-T4, t0 = 1.5 mm) by direct pin pressing. For a quantitative evaluation of the joint quality, tensile shear tests are carried out and the influence of different pin heights, pin number, and pin arrangements, as well as different joining strategies on the joint strength is experimentally evaluated. It is proven that a single pin structure with a diameter of 1.5 mm and an average height of 1.86 mm achieves a maximum tensile shear force of 1025 N. The results reveal that the formation of a form-fit during direct pin pressing is essential for the joint strength. By increasing the number of pins, a linear increase in force could be demonstrated, which is independent of the arrangement of the pin structures.

scholarly journals Enhancement of the interface of friction welded steel-aluminium joints

2020 ◽  
Author(s):  
Bernd-Arno Behrens ◽  
Deniz Duran ◽  
Tim Matthias ◽  
Ingo Ross
Keyword(s):  
Joint Strength ◽  
Step Function ◽  
Inductive Heating ◽  
Destructive Testing ◽  
Welded Steel ◽  
Counter Pressure ◽  
Local Properties ◽  
Novel Concept ◽  
Tailored Forming ◽  
Joining Process

AbstractLightweight multi-material components are of great importance for the transport industry. Not only the component’s weight can be decreased, but also its local properties can be adapted to different loading profiles. Tailored Forming is a novel concept for producing multi-material components. By using a joining process, the creation of a bond between different materials takes place in the first step of the process chain. In the subsequent steps, multi-material workpieces are processed in their joined state while maintaining or improving the joint strength. This study focuses on steel-aluminium joints, which were created by friction welding and further processed by induction heating and impact extrusion. A counter pressure superposition mechanism was implemented in the extrusion tooling to control the stress state during plastic deformation. Flow behaviours of steel and aluminium are largely different at a given temperature, which necessitates a near step-function temperature distribution in the hybrid billet to obtain matching flow stresses. An inductive heating strategy was developed which led to a temperature gradient in the billets before extrusion. Extruded billets were analysed by destructive testing methods and metallography. The bond could be maintained after extrusion when counter pressure superposition was used; but no improvement could be obtained. Without counter force superposition, however, cracks were observed in the joining interface and the joint strength decreased. This paper discusses the aforementioned findings in the current process design and makes suggestions on how the involved processes should be reconfigured to improve the joint strength.

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