New Approach for Modelling of the Welding Processes
The applying of new technologies is connected with considerable outlays to receive the optimal welding regimes, metallographic research of welding seams, joint quality control and other facilities, which can be considerable lowered, using modelling of the welding processes. We propose to use new approach for modelling – analogue modelling, which is based on process investigation, using logical functions. Some practical applying examples of the analogue modelling are offered in this paper. The analogue model of the heat input during resistance welding of wires with coating is described in detail. Using analogue modelling we can solve direct problems of thermal conductivity, it mean that we can predict temperature field, obtained as a result of influence of welding source of heat. The effectiveness of analogue modelling using is proven.
RESEARCH ON THE SURFACE COATINGS INFLUENCE ON FORMATION MECHANISM OF THE RESISTANCE WELDS
The goal of the work is the research of formation mechanism of the spot resistance welds in the case of copper wires with nickel and tin coatings. The existing approaches for investigation of the formation mechanisms of welds of wires with and without coatings are analysed. A new approach for modeling of welding joint formation is offered. The analog model of the heat input during resistance welding of
Joint strength of aluminum ultrasonic soldered under liquidus temperature of Sn–Zn hypereutectic solder
Abstract In order to obtain high-strength aluminum joints, ultrasonic soldering of 1070 aluminum was conducted under liquidus temperature of Sn–Zn hypereutectic solder. A device for ultrasonic soldering was assembled, which propagated ultrasonic vibrations in a direction perpendicular to joining surfaces. This device joined 1070-Al using quasi-melting Sn–Zn hypereutectic solder without using any artificial spacers. The strength of the solder joints was evaluated by tensile tests. The optimum joining conditions were determined, and the effects of solder compositions and soldering temperature on the joint strength and the solder layer thickness were examined. In this ultrasonic soldering process, the highest tensile strength was obtained for the solder joints fabricated at 220 °C for the Sn–23Zn and Sn–40Zn solder compositions. The joint strength was equivalent to that of 1070-Al heat treated at 220 °C. The sound joints were obtained at 300 °C using Sn–82Zn solder, the liquid phase volume fraction of which was theoretically only 0.24. The present work also revealed that the thickness of retained solder layer in the joint after ultrasonic soldering could be estimated. Accordingly, ultrasonic soldering under the liquidus temperature of Sn–Zn hypereutectic solder could be a spacer-free soldering method to obtain high-strength aluminum joints.