EFFECTS OF PRE-COATING TREATMENT AND BOND-COAT COMPOSITION ON THERMAL CYCLING BEHAVIOR OF TBC SYSTEMS


Adanır H.

I-Managers Journal on Future Engineering and Technology, cilt.16, sa.1, ss.36-42, 2020 (Hakemli Dergi)

Özet

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.