The importance of the problem of hole-filling by a molten metal lies in the application of brazing for repairs in space, under microgravity conditions. The negligible effects of gravity and dominance of capillary forces can be approximated under terrestrial conditions, provided that the holeand the quantity of liquid are small, as quantified by the Bond number. In this paper, we report experimental results, modeling, and analysis of the hole-filling problem using the liquid aluminum brazing alloy on aluminum substrate. Depending on the hole size, the capillary driven flow may resultin the hole being either filled or not filled. The equilibrium problem (energy minimization) has multiple solutions in some regions of the parameter space. Therefore, the experimental outcomes may depend on the availability of sufficiently strong perturbation, required to dislodge the system froma metastable equilibrium. We report good agreement between experimental results and theoretical/computational predictions. In general, a deeper and narrower hole favors the filled outcome.
|Journal||Physics of Fluids|
|State||Published - Mar 1 2021|
Bibliographical noteFunding Information:
This work was funded by NASA’s Physical Sciences Research Program (Grant No. NNX17AB52G) and Roscosmos Research ISS Program (Joint Space Experiment REAL). The authors acknowledge the guidance offered by Dr. Richard Grugel (NASA MSFC) throughout the duration of the project work between 2016 and 2020. Materials and the early stage of this work are supported by Gr€anges AB (Finspång, Sweden). TRILLIUMVR (the cladded brazing sheet in this study) is protected by U.S. Patent No. 8871356 as well as corresponding patents and pending patent applications in other major countries. C.Y. acknowledges Dr. Doug Hawksworth (Diomedea, Inc.) for bringing the attention to the hole-filling phenomenon. The team acknowledges Mr. Adam Price (University of Kentucky) for his technical support. K.L. acknowledges fruitful discussions with Professor Kenneth A. Brakke (Susquehanna University) regarding mesh refinement and functionalities of Surface Evolver.
© 2021 Author(s).
ASJC Scopus subject areas
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Fluid Flow and Transfer Processes