scholarly journals Effect of Microstructural Parameters on the Tensile Property of WC-12~22wt%Co Cemented Carbide

2021 ◽  
Vol 59 (3) ◽  
pp. 201-208
Author(s):  
Seong Hyeon Ryu ◽  
Kyung Il Kim ◽  
Wooram Noh ◽  
Sang Sub Kim ◽  
Gue Serb Cho
Keyword(s):  
Tensile Strength ◽  
Free Path ◽  
Fine Particles ◽  
Mean Free Path ◽  
Tensile Specimen ◽  
Cemented Carbide ◽  
Microstructural Parameters ◽  
The Mean ◽  
Average Size ◽  
Binder Metal

Cemented carbide is a kind of composite material in which fine particles of carbide are embedded into the matrix of a binder metal. It has a long service life because of its superior mechanical properties. In this study, the overall tensile behavior of a cemented carbide, WC-Co, was investigated by considering its characteristic microstructure parameters. Tensile strength and strain to fracture were evaluated by measuring the stress-strain curves of a standard tensile specimen. Scanning Electron Microscopy (SEM) was used to analyze both the average size and contiguity of WC carbide particles, as well as the mean free path of the Co (cobalt) binder. Specific correlations between mechanical and microstructural features were examined and elucidated for various volume fractions of the binder metal. The Co content and the mean free path of the Co binder were in a proportional relationship, and tensile strength showed an opposite tendency to Co content. Regarding Young’s modulus and strain, it was confirmed that a large difference appears depending on the crystal structure of the Co phase. Furthermore, by probing topology of the fractured surface of the tensile specimen it was determined that the existence of irregular voids could contribute to the statistical variance in the measured values.

Crystal Plasticity Analysis of Mechanical Response and Size Effect in Two Phase Alloys with Dispersion of Fine Particles

2014 ◽  
Vol 626 ◽  
pp. 264-268
Author(s):  
Yelm Okuyama ◽  
Tetsuya Ohashi
Keyword(s):  
Free Path ◽  
Crystal Plasticity ◽  
Work Hardening ◽  
Mechanical Response ◽  
Fine Particles ◽  
Mean Free Path ◽  
Experimental Result ◽  
Two Phase ◽  
The Mean ◽  
Element Technique

Plastic deformation and dislocations accumulation in a steel alloy dispersed with vanadium carbide particles is numerically analyzed by a crystal plasticity finite element technique and work hardening characteristics are discussed. Increment of dislocation density that contributes to work hardening is calculated from the mean free path of dislocations. The mean free path is defined by the spacing of forest dislocations and the average spacing of dispersed particles. Obtained yield stress and work hardening characteristics was close to that of experimental result, except that the value of work hardening rate was higher than that of experimental one.

scholarly journals Ballistic Heat Transport in Nanocomposite: The Role of the Shape and Interconnection of Nanoinclusions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1982
Author(s):  
Paul Desmarchelier ◽  
Alice Carré ◽  
Konstantinos Termentzidis ◽  
Anne Tanguy
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Free Path ◽  
Mean Free Path ◽  
Strong Increase ◽  
Moderate Increase ◽  
Energy Propagation ◽  
The Mean ◽  
Dynamics Simulations

In this article, the effect on the vibrational and thermal properties of gradually interconnected nanoinclusions embedded in an amorphous silicon matrix is studied using molecular dynamics simulations. The nanoinclusion arrangement ranges from an aligned sphere array to an interconnected mesh of nanowires. Wave-packet simulations scanning different polarizations and frequencies reveal that the interconnection of the nanoinclusions at constant volume fraction induces a strong increase of the mean free path of high frequency phonons, but does not affect the energy diffusivity. The mean free path and energy diffusivity are then used to estimate the thermal conductivity, showing an enhancement of the effective thermal conductivity due to the existence of crystalline structural interconnections. This enhancement is dominated by the ballistic transport of phonons. Equilibrium molecular dynamics simulations confirm the tendency, although less markedly. This leads to the observation that coherent energy propagation with a moderate increase of the thermal conductivity is possible. These findings could be useful for energy harvesting applications, thermal management or for mechanical information processing.

Experiments on the flow of heat in liquid helium below 0.7 °K

1958 ◽  
Vol 246 (1246) ◽  
pp. 390-405 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Helium ◽  
Free Path ◽  
Empirical Relation ◽  
Mean Free Path ◽  
Series Of Experiments ◽  
The Mean ◽  
Set Up ◽  
Low Pressures ◽  
Measured Thermal Conductivity

A series of experiments has been performed to study the steady flow of heat in liquid helium in tubes of diameter 0.05 to 1.0 cm at temperatures between 0.25 and 0.7 °K. The results are interpreted in terms of the flow of a gas of phonons, in which the mean free path λ varies with temperature, and may be either greater or less than the diameter of the tube d . When λ ≫ d the flow is limited by the scattering of the phonons at the walls, and the effect of the surface has been studied, but when λ ≪ d viscous flow is set up in which the measured thermal conductivity is increased above that for wall scattering. This behaviour is very similar to that observed in the flow of gases at low pressures, and by applying kinetic theory to the problem it can be shown that the mean free path of the phonons characterizing viscosity can be expressed by the empirical relation λ = 3.8 x 10 -3 T -4.3 cm. This result is inconsistent with the temperature dependence of λ as T -9 predicted theoretically by Landau & Khalatnikov (1949).

Light scattering by phonons in the presence of a heat flow

1968 ◽  
Vol 46 (24) ◽  
pp. 2843-2845 ◽  
Author(s):  
Allan Griffin
Keyword(s):  
Light Scattering ◽  
Heat Flow ◽  
Temperature Gradient ◽  
Free Path ◽  
Mean Free Path ◽  
Photon Scattering ◽  
The Mean ◽  
Anti Stokes

If the temperature in an insulating crystal decreases in the z-direction, there are more phonons with momentum qz > 0 than with qz < 0. The resulting difference between the Stokes and anti-Stokes Brillouin intensities is proportional to the mean free path of the phonon involved and to the temperature gradient. The effect should be observable by either neutron or photon scattering.

Role of neutral-particle bombardment in dust–dust interactions in plasmas

2001 ◽  
Vol 65 (4) ◽  
pp. 257-272 ◽  
Author(s):  
Ya. K. KHODATAEV ◽  
G. E. MORFILL ◽  
V. N. TSYTOVICH
Keyword(s):  
Free Path ◽  
Particle Bombardment ◽  
Neutral Particle ◽  
Mean Free Path ◽  
Dust Particles ◽  
Neutral Particles ◽  
Additional Force ◽  
Numerical Coefficient ◽  
The Mean

It is shown that the interaction of dust with neutral plasma particles can lead to attractive forces between dust particles, both in the case where the distance between dust particles is less than the mean free path of neutral particles and in the case where it is greater. The expressions for attractive forces differs in the two limits only by a numerical coefficient. The additional force of dust interaction is found to be due to the neutrals created by recombination of charged plasma particles on the surface of dust particles. The influence of radiative dust cooling on dust–dust interaction is considered.

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