Thanks to their remarkable electrical properties, thermally sprayed copper coatings are widely used in many industrial sectors, such as electronics, automotive, or electro-mobility. In the cold spray processes, the powder with particles sizes typically 5 to 25 µm, is injected from a pressure chamber into a convergent-divergent nozzle (De Laval type) and accelerated to high velocities in a preheating inert gas stream. The coatings are formed by plastic deformation of the heated particles due to their high kinetic energy when impact the substrate.
In the current research, a one-step hybrid process – laser assisted low pressure cold spraying (LA-LPCS), was applied to develop high quality copper-based coatings. The laser beam was applied at three different stages of the coating deposition: i) pre-heating and activation of substrate surface, ii) overlapping to the powder jet resulting in the formation of a well-bonded coating with high rate of deposition, and iii) post-treatment for the densification of single layers and smoothing of the coating surface.
The variation of the laser parameters such as laser power, travel speed, powder morphology on the coating properties and process efficiency was investigated. Combination of the laser technology with the low pressure cold spray process resulted in a major improvement of the coating properties. An increase in the deposition rate compared to the laser cladding and deposition efficiency related to the thermal spray can be achieved. Moreover, there is a great potential for high surface coatings with high adhesion on the substrate to be produced.