Failure behavior of coated nickel-based superalloy under thermomechanical fatigue

Abstract

Thermomechanical fatigue (TMF) is a major life limiting factor for gas turbine blades. In this study, the failure behavior of NiCrAlY overlay coated nickel-based superalloy M963 was investigated under out of phase (OP) TMF. All tests were carried out under mechanical strain control with a cyclic period of 200 s. Results revealed that the fatigue life of high velocity oxygen fuel spraying (HVOF) coated specimen was longer than that of air plasma spraying (APS) coated one, but shorter than that of bare superalloy M963 at a given strain range. It was found that cracking process in the APS coating was different from that in the HVOF coating, which was shown by the sketches to understand the crack initiation and propagation behavior.

Improvement in oxidation behaviour of steel by B4C–TiB2–TiC–Ni coating

“…Therefore, protective coatings are used to provide high temperature oxidation and corrosion resistance for these materials. 2,3 Many approaches have been used for reducing the corrosion damage, one of which is the use of HVOF coatings. 4 Ceramic materials, such as boron carbide (B 4 C) and titanium carbide (TiC), show superior wear and oxidation behaviour at ambient and high temperatures.…”

“…Therefore, protective coatings are used to provide high temperature oxidation and corrosion resistance for these materials. 2,3 Many approaches have been used for reducing the corrosion damage, one of which is the use of HVOF coatings. 4…”

Oxidation behavior of arc-sprayed FeMnCrAl/Cr3C2–Ni9Al coatings deposited on low-carbon steel substrates

“…These metals or alloys are not resistant to high-temperature corrosion. Therefore, protective coatings are essential to providing high-temperature oxidation and corrosion resistance to these materials to extend their service life under harsh conditions, especially in industrial boilers [2,3]. Many approaches have been applied for reducing the corrosion damage, one of which is thermal spray coating, such as Cr 3 C 2 -NiCr and Co-based coatings by high velocity oxygen fuel spraying, Ni-based cermet coatings, Ni-20Cr and Ni 3 Al coatings by plasma spraying, as well as FeNiCrB and NiCr coatings by arc spraying [4][5][6][7][8].…”

Platinum-Based Alloys and Coatings: Materials for the Future?

“…Although the nickel-based superalloys have excellent mechanical properties, they have nearly reached their temperature limit for operation in turbine engines, unless extreme aircooling is used, due to the relatively low melting point of nickel (1543°C) and dissolution of the strengthening ' precipitates at ~1150°C. This limits the current operating temperature of NBSAs to ~1100C (Chen et al 2009). There have been many developments to increase the temperature capability of these alloys with complex alloying additions and improvements in processing technology and alloy design methodology (Davis, 1997), but in 24 years an increase of only ~100C has been accomplished, with little scope for any further increases.…”