Open porous metallic foams with thermal barrier coatings and cooling hole array for high temperature turbine applications

Journal
High temperature material processes  
Volume
11
Issue
3
Start Page
321
End Page
343
Citation
High Temperature Material Processes 11 (3): 321-343 (2007-12-01)
Publisher DOI
10.1615/HighTempMatProc.v11.i3.20
Scopus ID
2-s2.0-38149000735
Publisher
Begell House
Open porous and high temperature resistant Ni-base structures are developed for the requirements of an effusion cooling. A metallic foam, that is produced by the SlipReactionFoamSintering (SRFS)- process, a powder metallurgical process, is used as the open porous structure. To withstand the high temperatures in the combustor of a gas turbine of up to 1520 °C the samples are covered with a Thermal Barrier Coating (TBC) using thermal spraying processes, which hermetically seals the open porous structures. Laser drilling is used to form blind holes through the TBC into the metallic foam in order to establish connections to a number of pores, which make the mass flow of the cooling fluid possible. Therefore, the pores must not be clogged by molten material during laser drilling. The aim of this paper is to point out the general feasibility of the production steps of the open porous multi-layer component made out of the open porous foam and the thermal barrier coating, which is then opened by laser drilling. First design suggestions are given for the foam pore structure to enable the application of the TBC and for the dimension of the laser drilled holes.
Subjects
Combustion chamber
Cooling holes
Laser drilling
Metallic foams
Thermal barrier coating (TBC)
Thermal spraying
DDC Class
530: Physik