Figure 4.

Microstructural features. (a) The electrosprayed surface (the 60 ppi template was electrosprayed for 7 min and sintered at a maximum temperature of 1400°C). (b) An example of inverted pyramid shape observed, gradually narrowing towards the innermost surface (the 60 ppi template was electrosprayed for 3 min and sintered at a maximum temperature of 1400°C). (c) The thick ceramic coating forms a pyramidal shape on top of the foam with increased spraying time (60 ppi template). ESED, environmental secondary electron detector.