Hot Corrosion of Aluminide Coated Ti-Al-Cr-Nb-Zr-Y Intermetallic Alloys

Abstract:

Pack aluminide coatings were performed on a Ti-Al-Cr-Nb alloy doped with zirconium and yttrium having two phase of a₂-Ti₃Al and g-TiAl microstructure. The high activity TiAl₃-based coating was developed from aluminizing process carried out at 850°C for 25 hours in a pack containing 20%-wt Al, 2%wt NH₄Cl, and 78%wt Al₂O₃. During applications at high temperatures, the coating can degrade due to the interaction between the coated system and the environment exhibit high corrosion potentials. This study investigates the hot corrosion behavior of high-activity aluminide coated Zr-Y doped a₂-Ti₃Al/g-TiAlCrNb intermetallic alloy at 700°C, 800°C, and 900°C in a mixture of 90% Na₂SO₄ and 10% NaCl. The experimental results showed that the addition of Zr and Y in the alloy reduces significantly the hot corrosion rate of the coating as resulted from the interdiffusion of these elements from the alloy to the coatings and influence the behavior of the TiAl₃-based coatings.

• Periodical: Advanced Materials Research (Volume 1112)
• Pages: 363-366
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1112.363
• Online since: July 2015
• Authors: Eddy Basuki*, Fadhli Mohammad, Ahmad Fauzi, Djoko Prajitno
• Keywords: Aluminide Coating, Hot Corrosion, TiAl Alloys

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