Wednesday, August 27, 2014

Why Melt? Melting Without High Temperature

From the post "Young And On Heat"

\(F=4\pi E_s\Delta L=F_T=\sqrt{3}\rho D.\cfrac{\partial (d_s)}{\partial T}.\cfrac{1}{\alpha}\)

We see that by driving the system with  varying   \(T\),  we can set the system into resonance at

\(f_{res}=\cfrac{1}{2\pi}\sqrt{\cfrac{4\pi E_s}{{4}\pi\rho}}\)

where  \(m={4}\pi\rho\),  a sphere of radius 1, mass per unit length,

\(f_{res}=\cfrac{1}{2\pi}\sqrt{\cfrac{E_s}{\rho}}\)

\(E_s=\sqrt{3}E\)

where  \(E\) is the linear Young's Modulus and  \(\sqrt{3}\)  the 3D constant for the case of a sphere.

(\(E_s=E\) for the case of a rod.)

It might be that the sphere will melt at this thermal resonance frequency irrespective of the magnitude of the temperature.

If we consider that on increasing temperature, atoms in a solid vibrates at higher and higher frequency about its mean position in the solid lattice, this would suggest that at a particular temperature when the atoms are vibrating at this resonance frequency,  \(f_{res}\),  the atom will simply break away from the lattice.  That is to say, the solid melts.

So melting is a case of the atoms vibrating at resonance frequency in heat.  And that it is possible to melt without high temperature but by applying  \(T\)  at the correct resonance frequency.