Effect of MCrAlY coating on the low-cycle fatigue behavior of a directionally solidified nickel-base superalloy at different temperatures

• MCrAlY coating was fabricated on the surface of DZ125 by EB-PVD.
• LCF behavior of DZ125/coating were investigated at 850 °C and 980 °C.
• The coating had no effect on fatigue cracking of DZ125 both at 850 °C and 980 °C.
• The coating on DZ125 improved its LCF life under lower stress at 850 °C.
• The coatings had no effect on fatigue life of DZ125 at 980 °C.

The low-cycle fatigue (LCF) behavior of the directionally solidified nickel-base superalloy DZ125 was studied in the uncoated state and in the Electron Beam Physical Vapor Deposition (EB-PVD) coated condition at 850 °C and 980 °C. The coating was found to be beneficial under low stresses at 850 °C; however, the coating effect is almost negligible at 980 °C or under high stresses at 850 °C. Scanning electron microscopic examination reveals that the coating had no effect on fatigue cracking of specimens both at 850 °C and 980 °C.