Moly Disilicide Coating - Plasma Spraying

Moly Disilicide Coating - Plasma Spraying As Follows:

Of Mo and Si powder as raw material, according to Mo: Si = 1:2 (atomic ratio) mixed in the mixing unit 24h, the mixed powders in a good high temperature under an argon atmosphere from propagating synthesis MoSi2 powder, a spraying one powder (SHS synthetic powder);

The SHS of MoSi2 powder was pelletized and vacuum heat treatment to obtain spraying powder aggregates.

MoSi2 coating preparation and organizational analysis:

1. To K403 Hastelloy substrate material, whichever is the size 10 mm × 15 mm, the first surface of the substrate material degreasing, rust, sand washing process;

2. Using APS-2000 type atmospheric plasma spraying equipment, respectively, from the spread of the synthetic powder and aggregate powder coating materials, coating process parameters: power 50kW, gun tip and the sample relative distance 150 mm, argon gas flow rate 40 L / min, powder feeding rate of 18 g / min;

3. Using the D8-Advance X-ray diffractometer MoSi2 powder and coating testing phase composition;

4. Using JSM-6380LV scanning electron microscope coating microstructure morphology. Since the spread of the synthetic powder prepared by coating contains more MoSi2 Mo5Si3 and Mo phase, is not conducive to the oxidation resistance of the coating;

5. Using aggregates of powder coating materials can be prepared containing a small amount of Mo5Si3 Mo phase and dense phase and with good MoSi2 coating. (Self-propagating synthesis MoSi2 powder performance is not good, it is not discussed here)

molybdenum disilicide

Prepared by the molybdenum disilicide coating properties:

1) For the aggregate powder, MoSi2 coated with MoSi2 as a main phase and only a small amount of Mo5Si3 phase and a very small amount of Mo phase, the phase composition is better. Seen, the use of aggregates powder Plasma Spraying MoSi2 coating, which can significantly reduce the coating Mo5Si3 phase and Mo-phase production, thereby oxidation resistance is greatly improved. (Aggregates of powder average particle size is large, a smaller surface area reduces its presence in the spraying process oxidation, resulting coating contains only a small amount of Mo5Si3 and Mo phase.)

2) in the same coating process parameters, the particle size is too large, it will lead to melting of the granules poor, making the coating porous; when particle size is too small, particles, although fully melted, but its in the nozzle to the sample during the flight will severe oxidation, resulting in the coating section appear more pale white areas, which produce more molybdenum-rich phase, is not conducive to preparing the phase composition and improved coating;

In addition, the particle size is too small, will cause the powder feeding process of "blocking powder" phenomenon, resulting powder feeding discontinuous detriment Coating. SHS synthesis and aggregates powder particles during spraying can fully melted, making the coating cross-section and surface morphology is better.

a. SHS synthetic powder to its particle size is too small, resulting in MoSi2 coating contains more Mo5Si3 and Mo phase, is not conducive to the coating oxidation resistance.

b. using aggregates powder plasma spraying materials, can be prepared containing a small amount of Mo5Si3 and Mo phase and dense with good MoSi2 coating.

If you have any interest in our moly disilicide coating or other molybdenum alloy products, please feel free to contact us by email:, or by telephone:86 592 512 9696.

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