Plasma-sprayed Mo-Re coatings for glass industry applications

The molybdenum-based alloy powder materials containing 15 and 44 wt.% of rhenium were produced with application of powder metallurgy techniques including reduction and annealing operations. The alloys were synthesized from a mixture of ammonium perrhenate and metallic molybdenum. The powders were reduced at 900 °C and subsequently annealed at 1150 °C for 6 or 24 h. The obtained powders were used for production of protective coatings on the cermetallic surface by plasma spraying technique. Two types of coatings were prepared - from powders before and after annealing. The effects of plasma spraying parameters and powder processing on properties of the obtained powders and coatings, especially phase composition and microstructure, have been investigated. Annealing process influences the qualitative and quantitative phase composition of the powders, but has no significant effect on the microstructure of obtained coatings, as observed.