Influence of crystallite size and lattice spacing on thermal conduction of polycrystalline copper deposited by solid particle impingement: Contribution of electron and phonon conduction

The purpose of this study is to provide an explanation of the effective parameters influencing thermal conductivity of copper deposited by particle impingement after subsequent annealing, with special emphasis on the contribution of electron and phonon conduction. As a result, after annealing, thermal conductivity and porosity of copper converge on a specific range of 288.5-320.5Wm ^-1K ^-1 and 0.6-3.3%, respectively. Thermal conductivities of the coatings deposited by spherical powders are improved via annealing processes without a remarkable reduction of porosity. Furthermore annealing process increases the crystallite size and recovers the distorted lattice structures in (200), which hinders the passage of electrons and increases the compressive strain of parallel plane. The decrease of crystallite boundary areas via grain growth eliminates the interruption of the electron or phonon thermal conductivity directly from grain boundary scattering effect.