I-Managers Journal on Future Engineering and Technology, cilt.16, sa.1, ss.36-42, 2020 (Hakemli Dergi)
ABSTRACT
This paper discusses the effects of the pre-coating
treatment and the bond-coat composition on the lifetime and the behavior of
thermal barrier coating (TBC) systems. Some literature-based analyses have been
made on the influence of pretreating a thermal barrier coating composed of a
single crystalline Ni based super alloy CMSX-4, platinum aluminide bond coat
and an Electron Beam Physical Vapor Deposition (EB-PVD) processed ceramic top
coat, prior to deposition of the ceramic top coat. Some analyses show that the
specimens annealed in the oxygen containing ArH atmosphere 0 for 4 hours at
1080 C have a higher cyclic lifetime as compared to the standard treated specimens.
The increase in lifetime can be attributed to the formation of a stable and
defined thermally grown oxide prior to and during TBC deposition. Also, the
bond coat with the silicon gradient effectively prevents the diffusion of Mo
thereby increasing the TBC lifetime.