Influence of Si for heated corrosion behaviour of CoCrAlY coating
Sheikh Idrees Ali
The CoCrAlSiY coating was obtained by PVD coating (high velocity oxygen fuel) method. The hot corrosion resistance of the CoCrAlSiY coating with different Si concentrations (0.1wt%, 2.2wt% and 5.7wt%) at 900 ºC was discussed with the method for coating with hot salt with a mixed salt of 75 wt% Na 2 SO 4 + 25 wt% NaCl. The results showed that average corrosion penetration depth of the coating raised with the increase of the temperature, while the increase in Si concentration lowerred the average indentation depth for corrosion of the coating. Also CrSi, a metal silicide with a greater melting point, was generated within the CoCrAlSiY corrosion coating. Therefore this technique is helpful to improving the corrosion resistance of the coating.