Supporting Thermal Barrier Coatings By Detonation Spraying Versus Air Plasma Spraying: Assessment of Techniques and Layers Properties
25th Advanced Aerospace Materials and Processes (AeroMat) Conference and Exposition
16-19 Jun 2014
conference_type.international conference, Orlando
|| Stathopoulos Vassilis
, Sadykov Vladislav Aleksandrovich
, Ulyanitsky Vladimir Yurievich
, Truska Ion
, Smorygo Oleg L'vovich
, Mikutskii Vitalii Anatolʹevich
, Fedorova Yuliya E.
, Larina Tatyana Viktorovna
, Vinokurov Zakhar
, Salanov Aleksei Nikolaevich
, Kriventsov Vladimir Vladimirovich
, Stoyanovskii Vladimir Olegovich
, Ivanov Vyacheslav Pavlovich
Boreskov Institute of Catalysis SB RAS
Powder Metallurgy Institute NAS Belarus
M. A. Lavrentyv Institute of Hydrodynamics SB RAS
Plasma Jet LLC
Development of new low-cost efficient methods of high quality thermal barriers deposition on hot section components of aero-propulsion systems (turbine blades etc) is a vital task for aerospace industry. In this work, characteristics of thermal barrier coatings supported by detonation spraying (DS) and traditional air plasma spraying (APS) are compared. Particles of bond coat (NiCrAlY) and top-coat (YSZ) materials fed into hot gas streams as dry powders were deposited on planar Ni superalloy substrates. For DS computer –controlled CCDS2000 complex was used to provide strict control of combustion gases temperature, velocity and composition produced by acetylene-oxygen mixture detonation, and, hence, deposition parameters. To avoid oxidation, bond coat was supported using reducing atmosphere, while top coat was supported in oxidizing conditions. Development of coatings texture, composition and real/defect structure after annealing under air up to 1200 oC as well as after series of thermal shocks up to 1000 oC were studied by combination of diffraction methods (high resolution SEM and TEM with EDX, in situ XRD on synchrotron radiation, EXAFS) and spectroscopic methods (UV-Vis, XPS, SIMS, laser-excited luminescence spectra). Both morphology, texture and real/defect structure of top-coat YSZ layers were found to be quite similar for both deposition methods being comprised of porous aggregates of partially melted particles with some microcracks in between. Strong disordering of Zr coordination sphere in YSZ particles was revealed by EXAFS and UV-Vis. Thermal annealing does not change texture, microstructure and YSZ domain sizes, though some defects such as anion vacancies generated by deposition were annealed. Thermal shocks have not caused neither layers spallation not cracks between bond-coat and top-coat for both methods. Hence, highly –productive DS method providing characteristics of thermal barrier coatings similar to that of dry APS method is suitable for this application.
Support by THEBARCODE project (№310750-FP7) is gratefully acknowledged.