Effect of powder axial injection on microstructure and mechanical properties of Cr3C2-25(Ni20Cr) cold sprayed coatings
Effect of powder axial injection on microstructure and mechanical properties of Cr3C2-25(Ni20Cr) cold sprayed coatings
Monday, May 27, 2019
Cold spraying is one of the most promising and emerging technology to deposit coatings with excellent quality, low porosity, high bond strength and hardness while maintaining an original phase composition of the powder. The use of a new solution allowing axial injection enables further increase of coating properties. The Cr3C2-25(Ni20Cr) powder (Metco Diamalloy 3004) was sprayed on the Al 7075 alloy by means of cold spray system Impact Innovations 5/8 with new axial injection of powder (Central Injector Kit). Properties of obtained coatings were compared with coatings deposited with conventional radial injection of powder. The microstructure and chemical composition of the powders and the coatings were analyzed by means of SEM Jeol JSM–7100 and theirs phase composition was studied using Bruker D8 Discover diffractometer. The micromechanical testing of coatings was carried out with the use of nanoindentation technique (Nanovea). The topography of the coatings after spraying was analyzed by means of a Talysurf CCI-Lite non-contact 3D profiler. Both coatings exhibit negligible porosity, however the higher kinetic energy of feedstock particles sprayed with axial injection of powder caused increase of mechanical properties and deposition efficiency.
The work reported herein was funded by the National Science Centre, Poland (Project No 2017/25/B/ST8/02228).