Cold Gas Spray (CGS) deposition of several polymeric materials

Since its invention in mid 80s, the research on Cold Gas Spay (CGS) technology has focused on the application of metallic and composite materials. However, in recent years, the investigation of this technology has expanded into other materials, like polymers and ceramics.

With some years of research, the Thermal Spray Center (CPT) has successfully achieved the deposition by CGS of several polymeric materials, such as polyethylene (PE), polypropylene (PP), thermoplastic polyurethane (TPU), polyamide (PA) and polyether ether ketone (PEEK).

The initial powder feedstock materials and obtained coatings, were characterized by means LS (laser scattering), rheology, DSC (differential scanning calorimetry), TGA (thermo-gravimetric analysis), IR (Infrared analysis), XRD (X-ray diffraction), OM (optic microscopy), SEM (scanning electron microscopy), and mechanical testing.

The results of the CGS deposited coatings cross-sections, examined by SEM, showed continuous and uniform structure, with no signs of initial feedstock particles, visible in the coating. On the other hand, DSC and XRD analysis indicated, in most cases, no significant change in microstructure, between initial feedstock materials and final coatings.

This work reveals that, it is possible to produce uniform and continuous coatings of polymeric materials by CGS, mostly preserving the initial microstructure of the feedstock materials.