CCS and Power Systems
Advanced Energy Systems - Hydrogen Turbines
Coating Issues in Coal-Derived Synthesis Gas/Hydrogen-Fired Turbines
Performer: ORNL - Oak Ridge National Laboratory
Project No: FWP-FEAA070
Figure 1. Average lifetimes (number of 1-hour cycles to failure) for EB-PVD (electron-beam, physical vapor deposition) yttria-stabilized zirconia (YSZ)-coated superalloy specimens with two different platinum-containing diffusion bond coatings exposed in 1-hour cycles at 1150 °C in several environments. Two different superalloy substrates were evaluated. The bars note the standard deviation for 3 specimens of each type.
Figure 2. (a) Average coating (number of 1-hour cycles to failure) lifetimes for APS (air plasma sprayed) YSZ coated alloys X4 and 1483 16mm diameter superalloy coupons with HVOF NiCoCrAlYHfSi type bond coatings with two different average roughness (Ra) values exposed in 1-hour cycles at 1100 °C in dry and wet environments. Bars note one standard deviation for three specimens of each type. Light microscopy of polished cross-sections of failed X4-coated specimens exposed in 10 percent water vapor (b) Ra=5 after 440 cycles and (c) Ra=8 after 380 cycles. The arrow in (c) shows where thermally grown aluminum oxide is beginning to undercut an asperity in the higher roughness coating.