The cross-sectional microstructures at the interfaces of the TBCs
which survived after cyclic thermal exposure for 381 cycles (8,000 EOH: equivalent operating hour) are shown in Figure 3.
The conversion to coal as a fuel is also expected to impact the use of TBCs
. Although TBCs
themselves are expected to be only minimally corroded by the more aggressive nature of this atmosphere, significant effects may be expected on the substrate and bond coat.
The detrimental tetragonal to monoclinic phase transformation is related to large stresses (volume expansion of ~4%) and limits the lifetime of the TBCs
.Therefore, mechanical properties and lifetime are optimized when the maximum amount of the non-equilibrium tetragonal t' phase can be obtained.
The comparison of the TGO final deformation profile made with the experimental observation shows a good agreement indicating the correctness and effectiveness of the present procedure, which can guide the prediction of the failure in TGO for the future design and optimization for TBC
LHREs are realized by covering the combustion chamber walls (pistons, liners, head, valves), the exhaust ports and manifold with insulating materials, called Thermal Barrier Coatings (TBCs
The existence of voids and microcracks as one of the characteristics of air plasma sprayed coatings can be observed on the outer surface of TBCs
, as shown in Figure 3.
Thermal barrier coatings (TBC
) are being widely applied in many types of engines and in aircraft's gas turbines.
include yttria-stabilized zirconia, maritime corrosion-resistant coatings such as ceria-stabilized zirconia and MCrAlY (chromium-aluminum-yttrium where M stands for nickel, cobalt, iron or a combination), and alumina-stabilized zirconia (a toughening agent).
Caption: Figure 8: 3D view of initiation sites in specimens with TBCs
subjected to pure bending: (a) as-sprayed specimen ([N.sub.f] = 1.3 x [10.sup.5] cycles) and (b) oxidized specimen with ~5 [micro]m thick TGO layer between the bond coat and the top coat ([N.sub.f] = 8.6 x [10.sup.5] cycles).
Max Von Material yield Safety Mises [MPa] stress [MPa] factor Coating 458 560 (300[degrees]C) 1.22 Wrist pin housing 188 200 (150[degrees]C) 1.06 Piston crown under TBC
83 86 (250[degrees]C) 1.04 Alfin interface 125 130 (215[degrees]C) 1.04 [C] 2019 Politecnico di Torino
The upshot is that about one quarter ofthe global beverage market, estimated at about $500 billion per annum, is now fully in the grip of fifty TBCs
, with the five leading ones among them tightening their squeeze around one half of this figure.
TEAM NEWSDUBLIN TBCS
Cluxton D Byrne M Fitzsimons P McMahon J McCaffrey C O'Sullivan J Small B Fenton MD Macauley N Scully C Kilkenny B Howard P Mannion D Rock C Costello to CORK M White J Loughrey T Clancy K Flahive L O'Donovan T Clancy M Taylor I Maguire K O'Hanlon K O'Driscoll S White R Deane M Collins B Hurley L Connolly TV TIMES: Live on RTE from 6.30pm