Corrosion Properties of Cold-Sprayed Inconel625 Coatings
Tutkimustuotos: Konferenssiesitys, posteri tai abstrakti ›
|Tila||Julkaistu - 2018|
Nickel-based superalloys have high corrosion and oxidation resistance. For corrosion protection, thermally sprayed coatings need to be dense and impermeable in order to act as a real corrosion barrier layer. Cold spraying, as one of the thermal spray techniques, enables to produce high quality coatings from high-performance materials. Generally, cold spraying is based on higher particle velocities and lower process temperatures than in other thermal spray processes. The coating is formed in a solid state when powder particles impact on a sprayed surface with high kinetic energy, deform and adhere to the substrate or to other particles. Beneficially, coatings with low porosity and high denseness can be produced by using cold spray processing. This study focuses on the structural characteristics, residual stresses and corrosion properties of high-pressure cold-sprayed Inconel 625 coatings. Corrosion properties were evaluated with electrochemical polarization measurements whereas high-temperature corrosion behaviour was studied with an isothermal corrosion test at 550˚C under KCl deposit. Also, the effect of heat treatment on microstructure was studied and compared with HT-corrosion tested coatings in order to understand the influence of corrosion and high temperature separately. These coatings showed dense structures, indicating their potential for corrosion protection.