Molybdenum News Center

With Mo and Si powder as raw material, according to the Mo: Si = 1:2 (atomic ratio) were mixed in blender 24h, good powder will be mixed under an argon atmosphere by SHS synthesis MoSi2 powder, used as a coating one of powder. The self-propagating high-temperature synthesis of MoSi2 powder by granulation and vacuum heat treatment, get sprayed with aggregates of powder. 

 

MoSi2 coating preparation and tissue analysis: K403 Ni-based alloy matrix material, whichever is the size 10 mm × 15 mm, the first degreasing the substrate surface rust, sand blasting process. Using APS-2000-type atmospheric plasma spraying equipment, respectively, from the spread of synthetic powder and aggregate powder coating materials, spraying process parameters: Power 50kW, the relative distance gun tip and the sample 150 mm, argon gas flow 40 L / min, powder feed rate of 18 g / min. Using D8-Advance X-ray powder diffraction detection MoSi2 phase composition and coatings; using JSM-6380LV scanning electron microscopy coating microstructure morphology. 

 

SHS preparing synthetic powder coating contains MoSi2 and Mo5Si3 more of Mo, not conducive to the oxidation resistance of the coating; using powder coating material aggregates, can be prepared to contain small amounts of Mo and Mo5Si3 phase and dense compared good MoSi2 coating. 

 

Performance: (1) the agglomerated powder, MoSi2 MoSi2 as a main phase and the coating is only a small amount of Mo5Si3 phase and a very small amount of Mo phase which is preferably composed of phase. Visible, using aggregates MoSi2 powder coatings prepared by plasma spraying, can significantly reduce the coating produced Mo5Si3 phase and Mo phase, thereby greatly improved oxidation resistance. 

(2) Under the same coating process parameters, particle size is too large, it will cause the particles to melt poor, making porous coating; If the particle size is too small, although the particles can fully melted, but the nozzle to the sample during flight severe oxidation occurs, resulting in the coating cross-section appear more pale white areas, which produce more molybdenum-rich phase, is not conducive to better prepare the phase composition of the coating; addition, particle size is too small, will cause delivery powder process of "blocking powder" phenomenon, resulting in the continuous production of feed powder coating does not favor. Synthesis and self-propagating aggregates of powder particles during spraying can fully melted, making the cross-section and surface morphology of the coating better. 

More molybdenum product: http://www.molybdenum.com.cn
Tel: 0592-5129696 Fax：0592-5129797
E-mail:  This email address is being protected from spambots. You need JavaScript enabled to view it.
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Price: http://www.chinatungsten.com