Non-equilibrium heating situations

The heat conduction depth, in some cases, can be limited with short distances. This results in non-equilibrium heating situation. In this case, the lattice sub-system thermally separates from the electron sub-system in the heated region. The energy transfer can be formulated through the hyperbolic heating model incorporating the thermal separation of the sub-systems. In this chapter, the electron kinetic theory approach is adopted to model the non-equilibrium heat transfer in the heated region during the friction welding process. The mathematical arrangements for the solution of the heat equation is presented.