The HIERARCH research project focuses on the multi-hierarchical strengthening of protective coating materials to develop new coatings for applications requiring extreme chemical, high or low temperature, and mechanical resistance. The focus is on (a) investigating the formation of microstructures incorporating hierarchical precipitation and transformation-induced strengthening mechanisms in highly metastable, even amorphous, gas-atomised powders and coatings and (b) improving the lamellar cohesion of thermally sprayed coatings by exploiting powder surface modification.
Mastering the hierarchical structure of metastable phases and precipitates in the initial structure of the atomized powder and understanding the strengthening mechanisms of coatings made from them under loading are essential steps in successful material development for extreme conditions. The thermal spraying techniques being studied in the project include modern high kinetic thermal spraying techniques such as HVAF.
VTT Technical Research Centre of Finland Ltd.