Thermo-Mechanical Characterizations of Coatings for HP Turbines (original) (raw)

Development and Assessment of Coatings for Future Power Generation Turbines

Volume 5: Manufacturing Materials and Metallurgy; Marine; Microturbines and Small Turbomachinery; Supercritical CO2 Power Cycles, 2012

The NETL-Regional University Alliance (RUA) continues to advance technology development critical to turbine manufacturer efforts for achieving DOE Fossil Energy (FE's) Advanced Turbine Program Goals. In conjunction with NETL, Coatings for Industry (CFI), the University of Pittsburgh, NASA GRC, and Corrosion Control Inc., efforts have been focused on development of composite thermal barrier coating (TBC) architectures that consist of an extreme temperature coating, a commercially applied 7-8 YSZ TBC, a reduced cost bond coat, and a diffusion barrier coating that are applied to nickel-based superalloys or single crystal airfoil substrate materials for use at temperatures >1450ºC (> 2640ºF). Additionally, construction of a unique, high temperature (~1100ºC; ~2010ºF), bench-scale, micro-indentation, nondestructive (NDE) test facility at West Virginia University (WVU) was completed to experimentally address in-situ changes in TBC stiffness during extended cyclic oxidation exposure of coated single crystal coupons in air or steamcontaining environments. The efforts and technical accomplishments in these areas are presented in the following sections of this paper.

Vacuum-plasma multilayer protective coatings for turbine blades

Vacuum-plasma multilayer protective coatings for turbine blades, 2021

The methods of creating the advanced nanomaterials and nanotechnologies of functional multicomponent coatings Avinit (mono- and multilayer, nanostructured, gradient) to improve the performance of materials, components and parts are considered. The vacuum-plasma nanotechnologies Avinit were developed based on the use of gas-phase and plasma-chemical processes of atomic-ionic surface modification and the formation of nanolayer coatings in the environment of non-steady low-temperature plasma. Considerable attention is paid to the equipment for application of functional multilayer composite coatings: an experimental-technological vacuum-plasma automated cluster Avinit, which allows to implement complex methods of coating, combined in one technological cycle. The information about the structure and service characteristics of Avinit coatings has a large place. The results of metallographic, metallophysical, tribological investigations of properties of the created coatings and linking of their characteristics with parameters of sedimentation process are described. The possibilities of parameters processes regulation for the purpose of reception of functional materials with the set physicochemical, mechanical complex and other properties are considered. The investigation of creating of multilayer protective surface coatings Аvinit based on Ti - TiN for turbine blades by vacuum-arc method was carried out. The influence of different methods and modes of vacuum-plasma treatment of coated surface of substrates to the adhesion value of nanolayer protective Ti - TiN coatings is studied. On the basis of carried out investigations the technology of coating the steam turbines blades for protection against flow-accelerated corrosions is developed. The issues of development and industrial implementation of the latest technologies for applying wear-resistant antifriction coatings Avinit with the use of nanotechnology to increase the life of various critical elements of steam and nuclear turbines are covered in detail. The book is aimed at specialists working in the field of ion-plasma surface modification of materials and functional coatings application.

Vacuum-plasma protective coating for turbines blades

Mechanics and Advanced Technologies, 2020

The investigation of creating of nanolayer surface coatings based on Ti-TiN for turbine blades by vacuum-arc method was carried out. The influence of different methods and modes of vacuum-plasma treatment of coated surface of substrates to the adhesion value of nanolayer protective Ti-TiN coatings is studied. The best adhesion levels of the vacuum-plasma surface treatment with damage control of substrates by microarcs achieve during the treatment of substrates in the glow-discharge plasma with subsequent treatment in high-density plasma of two-stage vacuum-arc discharge and switch to Ti ions treatment were given. The optimal parameters of such a complex vacuum-plasma treatment of substrates to achieve the best adhesion of coatings are determined. The investigation with the propose of ratio definition between the thickness of the layers of Ti and TiN and the total thickness of the nanolayer coating with the value of microhardness and adhesion to the substrate was carried out. It is given that the coating has the best combination of such characteristics at a layer thickness of Ti and TiN, respectively, 2 nm and 8 nm and a total layer thickness of 15 μm with an additional sublayer with a thickness of 5 μm. On the basis of carried out investigations the technology of coating the steam turbines blades up to 1300 mm long for protection against flow-accelerated corrosions is developed. The developed coatings were applied to a batch of serial blades and placed as part of a turbine for operational testing at a nuclear power plant (Paks, Hungary).

Gas turbine coatings – An overview

The components of a gas turbine operate in an aggressive environment where the temperature of service varies from ambient to near melting point of materials which introduce a variety of degradation on the components. Some components that lose their dimensional tolerance during use require repair and refurbishment when high cost replacement is avoidable. Erosion of fly ash and sand particles damages compressor blades which cause engine failure at an early stage. Dovetail roots of the compressor blades are subjected to fretting fatigue due to the oscillatory motion caused by vibration. Casing of the compressor comes in contact with rotating blades due to shaft misalignment, ovality of the casing and or inadequate clearance which cause blade and casing damage. Close clearance control that has bearing on the efficiency of the engine is therefore required in addition to preventing fire where titanium to titanium rubbing might occur. Wear out of the several contact surfaces which undergo rotating and reciprocating motion occur during the running of the engine need protection. Hot gases that are produced by burning the contaminated fuel in the combustion chamber will cause oxidation and corrosion on their passage. In the hot section rotating and stationary components need thermal insulation from higher operating temperature leading to enhanced thermodynamic efficiency of the engine. This wide range of functional requirements of the engine is met by applying an array of coatings that protect the components from failures. Current overview, while not aiming at deeper insight into the field of gas turbine coatings, brings out a summary of details of these coatings at one place, methods of application and characterization, degradation mechanisms and indicative future directions which are of use to a practicing industrial engineer.

Laboratory and field corrosion behavior of coatings for turbine blades

Surface and Coatings Technology, 1997

The present work reports the results of a comparative evaluation of three commercial coatings for turbine blades: (i) low activity pack cementation aluminide; (ii) high activity pack cementation Pt modified aluminide: and (iiij slurry deposited Si modified aluminide. For a laboratory corrosion test, bare substrate (Udimet 520) and coated samples were subjected to two different salts baths, 25% NaCl-75% Na$04 and 100% NalSOA, at 750°C in an inert atmosphere (Ar) and a gas mixture of S03-SO&. For a rainbow teht, nine coated blades were mounted in a gas turbine for 10 000 h. The test results showed that for the N&l-Na2S0, bath the damage mode of bare samples was Type I hot corrosion, while for the 100% Na2S04 bath thedamage was Type II; this effect was independent of the tebt atmosphere. Coated samples showed an incipient corrosion for the same test,. In accordance with the damage intensity, the coatings were rated (from Worst to best) as: Al-Pt, Al, Al-Si. The rainbow test showed the same tendency; however, the corrosion damage was less intensive in all cases. 0 1997 Elsevier Science S.A.

Coating Degradation of First and Second Stage Gas Turbine Blades

High Temperature Materials and Processes, 2009

Degradation study of over-aluminized CoCrAlY coatings (GT-29+) on conventionally cast (CC) GTD-111 Ni based super alloy substrates was investigated by evaluating first and second stage turbine blades after their 48,000 h of original services. The degradation evidences such as enlargement of the inter-diffusion zone, aluminum depletion from both top aluminide and CoCrAlY coating and related phase formations were observed by using an ΕΡΜΑ. The elemental mapping and quantitative analysis of the phases were also performed using WDS device attached to ΕΡΜΑ. Microhardness changes along the duplex coating thickness for both blades were determined by a Vickers microhardness tester.

IJERT-Analysis and Testing of Nanomaterial Coating on Turbine Blade of Gas Turbine Engine

International Journal of Engineering Research and Technology (IJERT), 2019

https://www.ijert.org/analysis-and-testing-of-nanomaterial-coating-on-turbine-blade-of-gas-turbine-engine https://www.ijert.org/research/analysis-and-testing-of-nanomaterial-coating-on-turbine-blade-of-gas-turbine-engine-IJERTCONV7IS11017.pdf Nickel based super-alloys are used in high temperature applications such as turbine blades of gas turbine engine. As they possess high strength, good creep resistance, good oxidation and corrosion resistance, they are used in high temperature applications. In Present work, the Inconel 718 was tested by using Thermo gravimetric analysis (TGA), Energy Dispersive X-ray analysis (EDAX) and Physical vapor deposition (PVD). Before coating of Inconel 718 with silicon nitride, TGA and EDAX is measured to find the decomposition and chemical composition at high operating temperature. The Inconel 718 was coated with Silicon Nitride Nano powder particles by using PVD (Sputtering coating) to achieve thermal conductivity. After coating the same TGA and EDAX process are repeated and measured to check whether the operating range (Temperature) is improved or not. According to TGA for coated sample (Inconel 718) the operating range has been improved. The results of the coated and uncoated samples are compared and conclude.

HIGH TEMPERATURE COATINGS FOR INDUSTRIAL GAS TURBINE USERS

High temperature coatings are used for protecting the high temperature turbine components from environmental attack due to oxidation and hot corrosion. These coatings have developed from sim ple aluminide coatings to complex overlay and duplex coatings. Over the past 15 years thermal barr ier coatings, which lower the temperature of the metal, have become increasingly used in industrial gas turbines.