A8

Working Group A | Metallurgical joint

 
 
a8_spp1640

Collision joining, flat clinching, plastic deformation, microstructural evolution, dynamic materials testing, strength and integrity of interfacial regions

Univ.-Prof. Dr.-Ing. habil. Martin Franz-Xaver Wagner, TU Chemnitz

 
 

Abstract:

Drop tower testing allows an analysis of mechanical properties at high strain rates – an important pre-requisite for an investigation of novel joining-by-deforming processes.
Drop tower testing allows an analysis of mechanical properties at high strain rates – an important pre-requisite for an investigation of novel joining-by-deforming processes.

Joining techniques based on plastic deformation allow an efficient design, e.g. of light-weight structures. The elementary processes associated with these techniques are quite complex, and therefore in many cases only empirical knowledge on joining of distinct pairs of materials under specific conditions exist. This is also true for the two techniques that will be considered in this project: collision joining and flat clinching. Both processes are associated with relatively high degrees of deformation in the joining region (about 2 to 3), and both allow joining of different material combinations; while flat clinching is characterized by only intermediate strain rates of about 1 s-1, very high strain rates of up to 104 to 106 s-1 occur during collision joining.

The key goal of this project is – together with two partner projects, each concerned with optimization and simulation of the respective joining techniques – to contribute to a more fundamental and systematic understanding of both processes. One can identify several related key questions that will be considered in this project from a materials science point of view. Technologically pure aluminum, an aluminum alloy and a C45 steel (and all feasible combinations of these materials) will be used to study how different initial microstructures affect the joining properties and interfacial strength and integrity during collision joining. Microstructural evolution in the joining zones will be studied for both techniques, and the direct comparison will yield information on rate effects. Mechanical testing of flat clinching of aluminum with wood will also be concerned with the anisotropy of the relevant material parameters and their effect on interface strength. A large mechanical parameter study will be performed on both initial materials and on joined materials and specimens provided by the partner projects. Thus, relevant data on rate-dependent mechanical behavior can be provided for the projects concerned with simulation, and interface integrity can be analyzed in detail. In addition, ultra fine grained and heat treated materials will be provided for the partner projects. The mechanical investigations will be complemented by a careful microstructural analysis (by optical and electron microscopy), and by instrumented micro and nanoindentation of joining zones. The relationships between initial microstructures, microstructural evolution in the joining zones and rate-dependent macroscopic properties will contribute to a better understanding of the joining techniques and hence potentially facilitate a broader range of applications.

 
 

Publications:

2019   
  On the microstructure and the origin of intermetallic phase seams in magnetic pulse welding of aluminum and steel M. Böhme, S. Sharafiev, E. Schumacher, S. Böhm, M. F.-X. Wagner
In: Materialwissenschaft und Werkstofftechnik (accepted)
2016   
  Microstructural characterisation of interfaces in magnetic pulse welded aluminum/aluminum joints S. Sharafiev, C. Pabst, M.F.-X. Wagner, P. Groche
In: IOP Conf. Series: Materials Science and Engineering 118, 2016, 012016
2015   
  Microstructural characterisation of interfaces in magnetic pulse welded aluminum/aluminum joints Sharafiev, S.; Pabst, C.; Wagner, M.F.-X. ; Groche, P.
In: OP Conf. Series, Materials Science and Engineering, 118, 2016
2014   
  A novel method to investigate the principles of impact welding: Development and enhancement of a test rig, experimental and numerical results Pabst, C.; Sharafiev, S.; Groche, P.; Wagner, M.
In: Advanced Materials Research, 966–967, 2014, 500–509
  Development of a novel test rig to investigate the fundamentals of impact welding Groche, P.; Wagner, M.F.-X.; Pabst, C.; Sharafiev, S.
In: Journal of Materials Processing Technology, 214, 2014, 2009-–2017
 

back to working groups