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Volume fraction
About: Volume fraction is a research topic. Over the lifetime, 16312 publications have been published within this topic receiving 374181 citations.
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15 May 2001-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a bi-continuous alumina:aluminum composites were made by infiltrating an alumina preform which had the structure of a reticulated ceramic foam.
Abstract: Bi-continuous alumina:aluminium composites were made by infiltrating an alumina preform which had the structure of a reticulated ceramic foam. The low density preforms were prepared from a polyurethane suspension of alumina powder which was pyrolysed and sintered after foaming. Higher density preforms consisted of ceramic foams with open cells. All these preforms were infiltrated with 6061 aluminium alloy using a modified squeeze caster fitted with a vacuum system and fine control of speed and pressure. The microstructure of the preform fitted an established relationship between the ratio of window diameter to cell diameter (k) and void volume fraction (Vp). Low k foams were infiltrated fully but on cooling below the solidus, interfacial debonding took place due to differential thermal contraction. This was overcome by modifying the processing conditions. High k foams which had high fractional porosity, retained sound interfacial bonding. The composites possess higher elastic modulus than conventional MMCs with a homogeneous reinforcement distribution at a given volume fraction. The loss of electrical conductivity is negligible in the lower volume fraction range because of the three dimensionally continuous aluminium phase. The experimental results are compared with a number of theoretical predictions. © 2001 Elsevier Science B.V. All rights reserved.
117 citations
TL;DR: In this paper, the growth of porous aggregates during initial mixing is investigated in a series of numerical simulations, and the collision rate constants as a function of fractal dimension, D, and aggregation number, i.e. D is assumed to be independent of aggregate size.
117 citations
TL;DR: In this paper, temperature induced degradation in Solid Oxide Fuel Cell (SOFC) Ni-YSZ anodes was studied using both impedance spectroscopy and three-dimensional tomography via Focused Ion Beam-Scanning Electron Microscopy.
117 citations
TL;DR: In this paper, new equations for the relative viscosity of concentrated bubble-bearing suspensions are developed using a differential scheme along with the solution of an infinitely dilute suspension of bubbles, which is useful in modeling the volcanic processes.
117 citations
TL;DR: Sedimentation velocities are reported for suspensions of nearly hard PMMA (polymethylmethacrylate) spheres as a function of volume fraction as a result of changes in volume fraction at the freezing and melting points.
Abstract: Reduced sedimentation velocities are reported for suspensions of nearly hard PMMA (polymethylmethacrylate) spheres as a function of volume fraction. The absolute sedimentation velocities are sufficiently slow compared to crystal-growth rates so that phase separation is achieved during the sedimentation process. As a result the analytic behavior of the measured sedimentation velocity changes as a function of volume fraction at the freezing and melting points. This transition serves as a definitive marker for comparison with theoretical predictions of sedimentation velocities for hard-sphere liquids and crystals.
117 citations