Electric resistance welding

About: Electric resistance welding is a research topic. Over the lifetime, 16761 publications have been published within this topic receiving 154851 citations.

Mechanical modeling of ultrasonic welding

Abstract: Tins article analyzes the mechanics of the metal ultrasonic welding process as a basis for a new solid free-form fabrication technology. Three-dimensional prototypes are constructed by ultrasonic welding of overlaid metal foil laminations, followed by contour cutting of the 2-D layers. This was implemented in the laboratory by a computer-automated ultrasonic welding station, and the normal compression, ultrasonic vibration, and process time for a single weld were experimentally optimized. The layered prototypes from aluminum foil exhibit density and stiffness comparable to solid specimens. Using strain gauge measurements on the prototype surface, the friction conditions at the foil-substrate interface were characterized via a simple analytical model of the elastic stress field and used to calibrate a full numerical simulation of the ultrasonic welding mechanics in order to relate the propagation of plastic deformation to the bond development. Besides solid metal and multi-material composites, cold ultrasonic welding enables integration of prefabricated components into intelligent structures, yielding active prototypes with internal functionality.

Computer simulation of resistance spot welding in aluminum: Part 1

Abstract: A computer-based model of resistance spot welding with hemispherical electrode tips has been developed to include simulation of elastic-plastic mechanical deformation as well as ohmic heating and thermal conduction. The primary effect of the mechanical deformation is in its influence on the contact read and current density developed at the faying surface. The model was used to simulate spot welding in aluminum alloys. Preliminary results show the effects of variations in input current, contact resistance, applied force and position of the cooling water with respect to the electrode tip. It is shown that the value of the contact resistance has a large effect on nugget formation in the spot welding of aluminum alloys and that the applied force has a significant effect arising from its effect on the area of contact at the faying surface. The formation of a resistance spot weld in aluminum is also sensitive to the position of the cooling water-electrode interface because of the high thermal conductivity of aluminum alloys.

Method for the control and/or regulation of a welding process

Abstract: The invention relates to a method for the control and/or regulation of a welding process, whereby on striking an arc (15), a welding process, adjusted according to various different welding parameters, is carried out. The control and/or regulation of the welding process is carried out by means of a control device (4) and/or a welding current source (2). During the welding process, the welding device (1) may be switched, in particular the functions and/or the operation types and/or the welding parameters and/or the welding programmes may be switched, without interrupting the welding process, in particular, without interrupting the arc (15), by means of a particular movement of the welding lance (10). For carrying out the switching, a welding parameter, in particular a welding or arc voltage and/or arc current is monitored and on exceeding and/or falling below a threshold value for the welding parameter, the switching of the welding device (1) is carried out by the welding controller.

Microstructures and properties of laser/arc hybrid welds and autogenous laser welds in pipeline steels

Abstract: Lasers are capable of producing welds with deep penetration, low distortion and faster travel speeds, compared to arc welding More recently, laser/arc hybrid welding processes have also been generating interest for industrial fabrication In this paper, six carbon–manganese, mainly pipeline, steels were welded using both autogenous Nd:YAG laser welding, and Nd:YAG laser/MAG hybrid welding The improvements in weld microstructures and weld metal toughness that are possible when using the hybrid process are described and illustrated Laser/arc hybrid welding is shown to be a process that can generate good quality welds in commercially available pipeline steels It also has the potential to complete girth welds in these steels with significantly fewer welding passes than are currently required for arc welded pipelines, reducing the joint completion time