Filling a hole by capillary flow of liquid metal–equilibria and instabilities

Abstract

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 hole and 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 result in 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 from a metastable equilibrium. We report good agreement between experimental results and theoretical/computational predictions. In general, a deeper and narrower hole favors the filled outcome.

Metastable Liquid Properties and Surface Flow Patterns of Ultrahigh Temperature Alloys Explored in Outer Space

“…[9][10][11][12][13][14][15] Especially, some novel properties and flow behaviors for a liquid in outer space has aroused great research interests in the fields of materials and chemistry. [16][17][18][19][20][21][22] Not only the liquid state is a fundamental problem in physical chemistry, surface chemistry and high temperature chemistry, [23][24][25][26][27] but also the research of liquid properties and the chemical bonds in outer space will play a significant role in multidisciplinary research connecting chemistry with space physics and metallic materials. [28][29][30][31] The metastable liquid thermophysical properties and surface flow patterns of refractory alloys with liquidus temperatures (T L ) beyond 2000 K face the challenges of high-temperature chemistry reactivity, intense volatilization, and droplet deformation.…”

Metastable Liquid Properties and Surface Flow Patterns of Ultrahigh Temperature Alloys Explored in Outer Space

“…[9][10][11][12][13][14][15] Especially, some novel properties and flow behaviors for a liquid in outer space has aroused great research interests in the fields of materials and chemistry. [16][17][18][19][20][21][22] Not only the liquid state is a fundamental problem in physical chemistry, surface chemistry and high temperature chemistry, [23][24][25][26][27] but also the research of liquid properties and the chemical bonds in outer space will play a significant role in multidisciplinary research connecting chemistry with space physics and metallic materials. [28][29][30][31] The metastable liquid thermophysical properties and surface flow patterns of refractory alloys with liquidus temperatures (T L ) beyond 2000 K face the challenges of high-temperature chemistry reactivity, intense volatilization, and droplet deformation.…”

“…However, there are still many mysteries for liquids at extraordinary environments, like superhigh or ultralow temperatures, and hyporgravity or microgravity [9–15] . Especially, some novel properties and flow behaviors for a liquid in outer space has aroused great research interests in the fields of materials and chemistry [16–22] . Not only the liquid state is a fundamental problem in physical chemistry, surface chemistry and high temperature chemistry, [23–27] but also the research of liquid properties and the chemical bonds in outer space will play a significant role in multidisciplinary research connecting chemistry with space physics and metallic materials [28–31] …”

Impact-induced hole growth and liquid film dewetting on superhydrophobic surfaces

“…18,19 Under external interference, such as the local air pressure or evaporation, the local area of the liquid film will become thinner and eventually rupture to form a dry hole. [20][21][22][23][24][25] That is, a circular contact line between the liquid, gas, and solid substrate is created. 3 In a liquid film, a dry hole is a defect that may grow or collapse, depending on the thickness of the liquid film, the wettability of the substrate, and various competing forces and boundary constraints.…”