Innovative and Highly Productive Joining Technologies for Multi-Material Lightweight Car Body Structures

Abstract

Driven by increasing costs for energy and raw material and especially by the European CO 2 -emission laws, automotive industry faces the challenge to develop more lightweight and at the same time still rigid and crash-stable car bodies, that are affordable for large-scale production. The implementation of weightreduced constructions depends not only on the availability of lightweight materials and related forming technologies, but also on cost-efficient and reliable joining technologies suitable for multi-material design. This article discusses the challenges and requirements for these technologies, based on the example of joining aluminium with press-hardened boron steels, what is considered as a very important material combination for affordable future lightweight mobility. Besides a presentation of recent developments for extending the process limits of conventional mechanical joining methods, new promising technologies such as resistance element welding are introduced. In addition, the performance, advantages, and disadvantages of the presented technologies are compared and discussed.

A simple but effective model for characterizing SPR joints in steel sheet

“…For materials with limited formability at ambient temperature, SPR joining may be performed with preheating of the sheet material, as described by Durandet et al (2010) using a laser, or by modifying the SPR die as shown by Drossel and Jäckel (2014). Meschut et al (2014) reported that nowadays, ultra-high strength materials and alloys are used in automotive industries, where limited deformation under load is required. Thus, it is necessary to understand the deformation behaviour of sheet material and rivet during the SPR process.…”

Improvement of cross-tension strength using concave electrode in resistance spot welding of high-strength steel sheets

“…To reduce CO2 emissions and minimize resource consumption, further weight reduction of a car body is demanded in the automobile industry [1,2]. Therefore, the use of high-strength steel sheets with a tensile strength of 340 MPa or higher have increased to achieve this goal.…”

Joinability of different thermoplastic polymers with aluminium AA6082 sheets by mechanical clinching

“…Such structures are extensively employed in automotive [1][2][3][4], aerospace, transport and naval industries.…”