A First Approach on Modelling the Thermal and Microstructure Fields During Aluminium Butt Welding Using the HYB PinPoint Extruder

A Semi-Analytical Model for the Heat Generation during Hybrid Metal Extrusion and Bonding (HYB)

“…This means that the thermal efficiency factor η varies in the range from 0.26 to 0.27, as evaluated from a comparison with the listed value for the gross power output in Table 2. It is noted that the computed  -values are in close agreement with those previously inferred from more sophisticated heat flow calculations using the numerical code WELD-SIM [24]. Therefore, the present model predictions, which are surprisingly accurate, confirm previous findings that only a minor fraction of the heat being generated is actually absorbed by the underlying base plates in a real joining situation.…”

“…This follows from an inspection of the supplementary modelling results presented in Appendix B (see Tables A2 and A3, respectively). Therefore, the present heat generation model is deemed to exhibit the required degree of predictive power to make it useful in combination with more advanced numerical models for simulation of the thermal, microstructure and residual stress fields, where the thermal efficiency factor is an essential input parameter [24].…”

“…However, due the novelty and uniqueness of the HYB process involving the use of FM additions, all these models previously developed for FSW are not readily transferable but need to be modified to allow for the flow of the FM through the extruder and into the groove. In a previous study by the authors, a finite element (FE) thermal model for the HYB process has been developed by exploiting the framework provided by the numerical code WELDSIM [24]. The model allows both the thermal and microstructure fields along with the resulting HAZ hardness profile to be calculated from knowledge of the net power input.…”

“…So far, the FE model has been applied to butt welding of 4 mm aluminium profiles of the AA6082-T6 type using a φ1.4 mm filler wire (FW) of matching composition. Based on a best-fit comparison between predicted and measured thermal cycles for two different positions within the HAZ, a thermal efficiency factor of 0.28 was obtained for the HYB PinPoint extruder [24]. This means that only a minor fraction of the heat being generated, as calculated from the torque acting on the rotating drive spindle, is actually absorbed by the base plates in a real joining situation.…”

Rapid Calculation of Residual Stresses in Dissimilar S355–AA6082 Butt Welds

“…Recently, a new solid-state joining method known as the hybrid metal extrusion and bonding (HYB) process has appeared on the horizon [22]. So far, various experimental studies of the HYB process applied to similar and dissimilar metals welds were carried out in order to better understand and predict the effect of process parameters on welded materials; however, only recently was a great effort spent in the development of numerical models [23,24]. Recently, good experimental results were found for dissimilar aluminumsteel butt welds obtained by the HYB technique [25][26][27].…”