Suspension spraying allows to create special coatings, which were only possible with expensive vacuum technologies in the past:

• With a suitable choice of the coating parameters columnar growing and porous coatings can be made.
  
  
• These coatings are used as thermal barrier coatings for gas turbines and jet engines.

[Cross section of a thermal barrier coating: high porosity]

Source: A. Killinger,P. Müller and R. Gadow,
High Velocity Suspension Flame Spraying and Suspension Plasma Spraying of Oxide ceramics
in: Thermal Spray 2012: Proceedings of the International Thermal Spray Conference (May 21-24, 2012, Houston, Texas, USA),
Eds: Basil R. Marple, Arvind Agarwal, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and André McDonald,
ASM International, 2012

[Side view of a thermal barrier coating: columnar growth]

Source: Forschungszentrum Jülich, N. Schlegel