Solid particle erosion of a plasma spray – physical vapor deposition environmental barrier coating in a combustion environment

Accelerated oxidation during 1350°C cycling of ytterbium silicate environmental barrier coatings

“…For highly-dense EBCs 25 or YbDSmodified EBCs, 26 which reduce oxidation rates up to 1000 h at 1316 • C, the transition to nonprotective oxidation may never occur. But during cyclic oxidation, vertical cracks in the top coat could form, 24 and during long in-service conditions, solid particle erosion could induce extensive brittle fracture, 50 with both events allowing direct access to the underlying silica former. Prior to these considerations, however, it may be critical for long lifetime EBCs that cristobalite formation be avoided.…”

Solid particle erosion in ceramic matrix composites and environmental barrier coatings: A perspective

“…9,[12][13][14][15][16][17][18][19][20][21][22] However, until recently, little work has been performed on characterizing and understanding the SPE behavior of CMCs and EBCs. [1][2][23][24][25][26] Conversely, extensive work has been performed on superalloys and TBCs. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] In fact, SPE of superalloys and TBCs remains an area of active research.…”

“…Similarly, as shown in Figure 11(B), the EBCs from the three studies follow a similar functional dependence with respect to impingement angle. All three EBCs exhibit an impingement angle dependence characteristic of a brittle-dominated mode of erosion where the erosion rate is maximum at normal (90 • ) F I G U R E 1 1 Comparison of three different EBCs as a function of (A) particle kinetic energy and (B) impingement angle (data from [25][26]51 ).…”

“…• and (B) 30 • . 26 It is expected that EBC/CMC components will replace at least some, if not all TBC/superalloy components in the hot section of gas turbines, so it is important to understand the relative erosion resistance between EBCs and TBCs. A comprehensive study was undertaken by the authors to compare the erosion rate of APS EBCs to APS and electron beam-physical vapor deposition (EB-PVD) TBCs.…”

“…A comprehensive study was undertaken by the authors to compare the erosion rate of APS EBCs to APS and electron beam-physical vapor deposition (EB-PVD) TBCs. 52 The study investigated a 100 wt.% Yb 2 Si 2 O 7 EBC (YbDS) and modified-Yb 2 Si 2 O 7 EBC (M2Y) that consisted of balance Yb 2 Si 2 O 7 with additions of 1.39 wt.% mullite (3Al 2 O 3 ⋅2SiO 2 ) and 2.33 wt.% YAG (Y 3 Al 5 O 12 ). More detail on the modified EBC can be found in Lee et al 53 where it was shown that the addition of these modifiers improved oxidation resistance.…”