Volume fraction

About: Volume fraction is a research topic. Over the lifetime, 16312 publications have been published within this topic receiving 374181 citations.

On the thermal conductivity of gold nanoparticle colloids.

Abstract: Nanofluids (colloidal suspensions of nanoparticles) have been reported to display significantly enhanced thermal conductivities relative to those of conventional heat transfer fluids, also at low concentrations well below 1% per volume (Putnam, S. A., et at. J. Appl. Phys. 2006, 99, 084308; Liu, M.-S. L., et al. Int. J. Heat Mass Transfer. 2006, 49; Patel, H. E., et al. Appl. Phys. Lett. 2003, 83, 2931−2933). The purpose of this paper is to evaluate the effect of the particle size, concentration, stabilization method and particle clustering on the thermal conductivity of gold nanofluids. We synthesized spherical gold nanoparticles of different size (from 2 to 45 nm) and prepared stable gold colloids in the range of volume fraction of 0.00025−1%. The colloids were inspected by UV−visible spectroscopy, transmission electron microscope (TEM) and dynamic light scattering (DLS). The thermal conductivity has been measured by the transient hot-wire method (THW) and the steady state parallel plate method (GAP met...

The toughening of alumina with nickel inclusions

Abstract: Brittle solids can be toughened by the introduction of ductile metallic inclusions. In the present study, the mechanical properties and oxidation resistance of Al2O3/Ni composites are investigated. The oxidation resistance of the ceramic/metal composite (8 × 10−11 g2 cm−4 s−1 at 1300° C) is comparable to that of many silicon nitrides. The fracture toughness of the composite containing 13 vol.% nickel is twice that of alumina alone. The square of the toughness enhancement for composites containing various amounts of nickel exhibits a linear relationship with the product of volume fraction and inclusion size, as predicted in theoretical models. For the alumina/nickel composite system, it is demonstrated that dissolved oxygen in the nickel increases the yield strength of nickel and enhances the toughness of the composite.

Mechanical buckling of nanocomposite rectangular plate reinforced by aligned and straight single-walled carbon nanotubes

Abstract: In this paper, the mechanical buckling of a functionally graded nanocomposite rectangular plate reinforced by aligned and straight single-walled carbon nanotubes (SWCNTs) subjected to uniaxial and biaxial in-plane loadings is investigated. The material properties of the nanocomposite plate are assumed to be graded in the thickness direction and vary continuously and smoothly according to two types of the symmetric carbon nanotubes volume fraction profiles. The material properties of SWCNT are determined according to molecular dynamics (MDs), and then the effective material properties at a point are estimated by either the Eshelby–Mori–Tanaka approach or the extended rule of mixture. The equilibrium and stability equations are derived using the Mindlin plate theory considering the first-order shear deformation (FSDT) effect and variational approach. The results for nanocomposite plate with uniformly distributed CNTs, which is a special case in the present study, are compared with those of the symmetric profiles of the CNTs volume fraction. A numerical study is performed to investigate the influences of the different types of compressive in-plane loadings, CNTs volume fractions, various types of CNTs volume fraction profiles, geometrical parameters and different types of estimation of effective material properties on the critical mechanical buckling load of functionally graded nanocomposite plates.