Influence of the wetting angle on capillary forces in pressure infiltration

Abstract

This work probes the influence of wetting on pressure infiltration. Pressure/saturation curves for the infiltration of packed F-1000 angular alumina particle preforms by liquid Cu-Al and Sn-Al alloys are measured using an instrumented high-temperature pressure infiltration apparatus.These are ceramic-metal systems in which the contact angle is documented to vary significantly with alloying, from non-wetting to wetting conditions. We show that adding Al to Sn or to Cu modifies the early percolation-dominated phases of infiltration and also the later, pore geometry dominated, phase of the infiltration process. Changes in contact angle brought by alloying cause the saturation/pressure curves to shift, yet for all systems of this work the curves remain entirely in the range of positive pressures, despite a transition to contact angles below 90°. Combining measured pressures for infiltration at fixed saturation with relevant sessile drop experiment data from the literature shows that for, the range of conditions explored here, the infiltration pressures required are proportional, not to the work of immersion, but to a linear function thereof. This result agrees qualitatively with prior work in the literature on the infiltration of nonmetallic liquids in porous media, and provides a master curve by means of which saturation curves and sessile drop data can be reconciled for this particular packed ceramic particle preform.

Coalescence of Immiscible Liquid Metal Drop on Graphene

“…Because metal and carbon can only form soft bonds via charge transfer from the π electrons in the sp 2 hybridized carbon to the empty 4 s states of metal 38 , we utilized the 12-6 Lennard-Jones (L-J) potential with a well depth ε = 0.0309 eV and size parameter σ = 3.422 Å to describe the Al-C interactions 39 , and a well depth ε = 0.01751 eV and size parameter σ = 3.288 Å was determined by Lorentz-Berthelot combining rules 40 41 to calculate the Pb-C interactions 42 . With these parameters, we calculated the equilibrium contact angle as 83.43° for Al and 112.12° for Pb on the flat graphene at 1500 K, which accord well with the experimentally measured contact angle of Al (about 85°) 29 and Pb (about 110°) 43 .…”

“…In this work, we performed molecular dynamic (MD) simulations to explore the coalescence behavior of Al and Pb films on different graphenes at the nanoscale and discovered the effect of substrates on the behavior of the two metals during alloy formation, which may provide theoretical guidance for fabricating this alloy. Besides, we discuss the variation of wettability for different substrates, which will be useful for applications in metallurgy 29 .…”

The Role of Local Instabilities in Fluid Invasion into Permeable Media

“…Despite its enormous importance and a substantial body of previous research 1–10 , there is as yet no conclusive understanding of this process at pore–scale 11–25 .…”

Interface Structure and Mechanical Properties of 7075Al Hybrid Composite Reinforced with Micron Ti Metal Particles Using Pressure Infiltration

“…However, defects, such as agglomeration, porosity and insufficient interfacial bonding, occur due to the poor wettability between the ceramics and the matrix, which severely limits their engineering application. Even though pressure infiltration could overcome the adverse capillary forces due to poor wettability utilizing applied load and is usually employed to produce composites of high microstructural quality, rapidly [5]. Extra ceramic surfaces modification is still adopted to improve wettability at aluminum/ceramic interfaces and reduce the threshold pressure for infiltration.…”