Resistance Spot Welding Coupled with High Frequency Acoustic Waves for Better Weldability of Dissimilar Materials
A hybrid welding process (URW) based on single phase AC resistance spot welding machine, integrated with high frequency acoustic waves is designed and tested for the joining of advance high strength steel TRIP (Transformation Induced Plasticity) 780 with Al 6061 alloy. Laser vibrometer have shown the mechanical oscillations of 34 microns in the workpiece due to high frequency acoustic waves. Improved design has shown significant improvement up to 300% increase in joint load bearing capabilities when it is compared to conventional resistance spot welding process. Crack free fully bonded interface is revealed by optical and scanning electron microscopy in case of URW.
Umair Shah - The Ohio State University
Electrical Hazard Reduction in Arc Welding
This presentation will focus on the electrical shock hazards associated with arc welding operations and the available methods that can be used to reduce the risks. These electrical hazards can be generally grouped as either secondary voltage shock or stray welding current faults. The talk will reinforce the best practices available to prevent harm from arc welding electricity, and to explore hazard reduction devices (engineering controls) that are evolving, but that are not yet in widespread use. For example, voltage reduction devices (or VRD’s) are available on many new arc welding machines or can be added as an accessory device to existing equipment, that will drastically reduce the shock risk from machine secondary (output) voltage for work in hazardous conditions. The risks associated with stray welding current faults, and the potential damage that can occur to electrical systems from these faults, will also be discussed.
Jim Galloway - Conestoga College