FGM Architecture with Heat-Resistant Properties

Svetlana A Oglezneva,Andrey A Smetkin,Maxim N Kachenyuk,S Bratan,S Roshchupkin

doi:10.1051/matecconf/202134602034

Abstract

A composite laminated heat-resistant material was manufactured by the method of spark plasma sintering. The architecture of a bonding layer between a substrate made of a heat-resistant superalloy and a ceramic coating containing sublayers of the intermetallic NiAl and a mixture of NiAl with 15 or 30 wt. % zirconia (8YSZ) is proposed. In a layered composite, the microhardness and thermal conductivity change monotonically on going from the substrate to the outer ceramic. The coefficient of linear thermal expansion of the bonding layer is close to that for ceramics in the operating temperature range.

Highlights

Effective thermal protection of high-temperature components in modern gas turbines is achieved due to ceramic thermal barrier coatings (TBC) on the surface of nickel superalloy parts
The thermal conductivity of Inconel 625 corresponds to 16.5 W / m · K [8], and the thermal conductivity of YSZ, determined by us at the same temperature (100 ° C), is 1.8 W / m · K, which coincides with the data [9]
The layers NiAl + 15 wt. % YSZ and NiAl + 30 wt. % YSZ form a thermal conductivity gradient when going from the superalloy to the outer ceramic

Summary

Introduction

Effective thermal protection of high-temperature components in modern gas turbines is achieved due to ceramic thermal barrier coatings (TBC) on the surface of nickel superalloy parts. To form structures with similar properties, additional aluminum, silicon, hafnium, tantalum, etc. [2,3,4] an additional sublayer of aluminum or platinum foil is created [5,6]. The purpose of this work was to obtain by the method of spark plasma sintering (SPS) and to study the binder between the superalloy and the external ceramic of the NiCrAlYYSZ system. For the formation of the outer coating, we used zirconium dioxide powder stabilized with 7.47 wt% Y2O3 (YSZ) (specific surface area 59.3 m2 / g, average particle size d50 = 2.4 μm) obtained by the method of reverse coprecipitation according to the procedure [7] To form structures with similar properties, additional aluminum, silicon, hafnium, tantalum, etc. are introduced into the sublayer. [2,3,4] an additional sublayer of aluminum or platinum foil is created [5,6].

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Conclusion