Aluminides coatings

J.H. Park and G. Dragel, Development of Aluminide Coatings on Vanadium-Base Alloys in Liquid Lithium, Eusion Reactor Materials Semiannual Progress Report for the Period Ending, DOE/ER-0313/13, 1993, pp.405-410. 

Structural Incoloy 800HT, Incoloy 800H (with aluminide coatings), AL610 Ceramics, Pt or Au coatings on superalloy structural materials... 

Incoloy, Inconel Bare—2-4 mg/cm2 in 1000 h 900°C Aluminide coatings— approximately 1 mg/cm2 in 1,000 h 900 C Intergranular corrosion observed for 800H Noble metal coatings may provide corrosion protection... 

Glasbrenner, H. et ah. The Formation of Aluminide Coatings on MANET Stainless Steel as Tritium Permeation Barrier by Using a New Test Facility, Vol. 2, Elsevier, Lisbon, 1997, p. 1423. 

Fig. 10. Schematic diagram showing the as-deposited structure of a low activity (left) and a high activity (right) diffusion aluminide coating on a nickel-base superalloy. The high activity coating would receive a heat treatment to convert the Ni2Al3 to NiAl.

Diffusion Zone f".g.ll. Schematic diagram of a platinum aluminide coating on a nickel-base superalloy. 

Figure 10.6 Optical micrograph showing the cross-section of an as-processed modified aluminide coating on a nickel-base superaUoy. This particular coating was fabricated under conditions which produced a second phase, PtAl2 (white contrast), in a matrix of S-NiAl.

Pt layers results in a two-phase (fi + PtAU) coating use of still thicker layers of Pt results in a complete layer of PtAl2 over the )6-NiAl. The presence of the Pt layer has also been clearly shown to increase the A1 uptake in the coating, for fixed aluminizing conditions. This is the result of the Pt lowering the activity coefficient of A1 in the coating. The Pt-modified aluminide coatings are observed to have markedly improved resistance to cyclic oxidation and hot corrosion. 

Figure 10.16 Optical micrograph showing the cross-section of a Pt-modified aluminide coating on a nickel-base single-crystal superalloy after oxidation at 1200 °C for 20 h. The original grain structure of the /3-phase is evident and y has begun to nucleate at /6 grain boundaries as a consequence of A1 depletion.

G. Fisher, W.Y. Chan, P.K. Datta, J.S. BumeU-Gray, Noble metal aluminide coatings for gas turbines, Platinum Met. Rev. 43 (1999) 59-61. 

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