Investigation of mixed alkaline earth phosphates. Synthesis and crystal structure of CaBa(HPO4)2: A new mixed alkaline earth hydrogenmonophosphate

Double plasma flame treatments were carried out on spray dried Cr2O3 agglomerated powders to increase their apparent density. The powders that were subjected to the first densification treatment didnʹt show the entirely melted state, and were fully melted only after the second plasma treatment. Plasma densification resulted in powder size decreasing as well as apparent density of particles and also resulted in the fluidity increasing due to the powder melting and surface smoothing effects. However, some parts of the particles after the second treatment showed a hollowed structure, especially for a particle size above 30 mu m. The influence of the thermal conductivity of powder and the gas pressure within aggregates exposed to the plasma flame in the particle densification process was discussed in detail. The powder density strongly influenced the structure of plasma sprayed coatings. The dense coatings with high hardness and high bond strength was achieved in the coatings produced from Cr2O3 powders after plasma densification.