Table 1
APS process parameters for deposition of YSZ ceramic outer layer of TBC
| Process parameters | Value |
|---|---|
| Plasma torch | A60 |
| Plasma gases Ar/H2 [NLPM] | 54/6; 48/12; 42/18 |
| Current [A] | 600; 700; 800 |
| Substrate radial velocity [rev/min] | 150 |
| Plasma torch feed rate [mm/s] | 3 |
| Time of spraying [s] | 1,110 |
| Spray distance [mm] | 100 |
| Spray angle [°] | 90 |
| Carrier gas [NLPM] | 6 |
| Powder feed rate [g/min] | 10 |
| Angle of powder injection to plasma plume [°] | 90 |
[i] APS, air plasma spraying; NLPM, normal liter per minute; TBC, thermal barrier coating; YSZ, yttria-stabilized zirconia
Fig. 1
Microstructure of the TBC YSZ layer: (A) initial image; (B) after binarization; and (C) image after binarization combined with the initial image.
TBC, thermal barrier coating; YSZ, yttria-stabilized zirconia
Fig. 2
Dependence of temperature (A) and velocity (B) of Metco-204NS powder particles in the plasma stream on the H2 flow rate and the current. NLPM, normal liter per minute
Fig. 3
Dependence of temperature (A) and velocity (B) of Metco-6700 powder particles in the plasma stream on the H2 flow rate and the current
Fig. 4
Contour plot of temperature and velocity of standard Metco-204NS particle (A, B) and Metco-6700 micropowder (C, D) with APS process parameters: current 800 A; H2 flow rate 18 NLPM (A, B) and 6 NLPM (C, D)
Fig. 5
Dependence of thickness (A), porosity (B), and hardness (C) of the TBC ceramic layer on the current and H2 flow rate, with the use of Metco-204NS ceramic powder.
NLPM, normal liter per minute; TBC, thermal barrier coating
Fig. 6
Microstructure (A, B) and surface morphology (C) of the TBC ceramic layer deposited from Metco-204NS powder using 800 A current and 12 NLPM flow rate of H2. 1: YSZ ceramic layer; 2: NiCoCrAlY metallic bond coat; and 3: Inconel 625 substrate material.
NLPM, normal liter per minute; TBC, thermal barrier coating; YSZ, yttria-stabilized zirconia
Fig. 7
Dependence of thickness (A), porosity (B), and hardness (C) of the TBC ceramic layer on the current and H2 flow rate, with use of Metco-6700 ceramic powder.
NLPM, normal liter per minute; TBC, thermal barrier coating
Fig. 8
Microstructure (A, B) and surface morphology (C) of the TBC ceramic layer deposited from Metco-6700 powder using 800 A current and 6 NLPM flow rate of H2. 1 – YSZ ceramic layer; 2 – NiCoCrAlY metallic bond coat; 3: Inconel 625 substrate material.
NLPM, normal liter per minute; TBC, thermal barrier coating; YSZ, yttria-stabilized zirconia
Fig. 9
Dependence of thickness (A), porosity (B), and hardness (C) of the TBC ceramic layer on the current and H2 flow rate, with use of Metco-6609 ceramic powder.
NLPM, normal liter per minute; TBC, thermal barrier coating
Fig. 10
Microstructure (A, B) and surface morphology (C) of the TBC ceramic layer deposited from Metco-6609 powder using 600 A current and 12 NLPM flow rate of H2. 1 – YSZ ceramic layer; 2 – NiCoCrAlY metallic bond coat; 3 – Inconel 625 substrate material.
NLPM, normal liter per minute; TBC, thermal barrier coating; ; YSZ, yttria-stabilized zirconia