Experimental and numerical study for Cu metal coatings at room temperature via powder spray process

The effect of Cu particle size on deposition behavior of Cu coating layer was investigated by experimental and numerical studies to understand coating behavior of metal films during aerosol deposition (AD) process. Experimental results showed that Cu film fabricated using 2 μm Cu powder had high deposition rate, low resistivity, and high internal micro-strain. Moreover, Cu films fabricated using 2 μm Cu powder had dense microstructure and Cu oxide phases due to elevated temperature caused by kinetic energy of impacted particles. However, Cu films prepared with 5 μm Cu powder formed filmy deposition layers with poor structural and electrical properties. Numerical results revealed that the generated strain and heat at the impact interface between the particle and the substrate were significantly decreased with increasing particle size. In contrast, the maximum shock pressure of particles was increased with increasing particle size. These results demonstrate that metal Cu particle with size of about 2 μm is suitable for forming good quality coating layers and that their bonding is associated with high compressive strain and thermal energy.