Determining High-Temperature Oxidation Resistance of (TI-Al-X-N) Based Coatings for Titanium Alloys

Basic titanium alloys are successfully used in modern aviation GTE (gas turbine engine). They are used for parts of a compressor and partly in low pressure part of turbine (intermetallic Ti-Al alloys) due to their high specific strength and at the same time low density, high corrosion resistance but can be used only up to 700 °C. The paper deals with the results of heat resistance testing at 750 °C of Ti-Al-(X)+N based thin ion-plasm multilayers coatings, with different priority of monolayers- intermetallic, conglomerate or nitride for gas turbine engine (GTE) blades from titanium alloys. All coatings showed high resistance during the test, with a maximum efficiency 42.8 of coating with a priority of conglomerate after 30 hours of testing.

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Improving the performance of gas turbine engine blades based on functionally oriented coatings

10.36652/1813-1336-2021-17-10-435-441 ◽

2021 ◽

pp. 435-441

Author(s):

A.N. Mikhaylov ◽

D.A. Mikhaylov ◽

E.A. Sheiko ◽

A.A. Colodyazhny

Keyword(s):

Mathematical Models ◽

Titanium Alloys ◽

Gas Turbine ◽

Surface Hardening ◽

Gas Turbine Engine ◽

Electrospark Alloying ◽

Steam Turbines ◽

Turbine Engine ◽

Technological Processes

Mathematical models have been developed for the surface hardening of VT20 and OT4 titanium alloys by electrospark alloying, which can be used in the design of technological processes for the manufacture of titanium blades of steam turbines.

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STUDY OF A HIGH-TEMPERATURE INTERMETALLIDE MATRIX OF THE Ni–Al–Co SYSTEM FOR PRODUCING STRUCTURAL ALLOYS WITH INCREASED PLASTICITY (review)

Proceedings of VIAM ◽

10.18577/2307-6046-2021-0-9-3-10 ◽

2021 ◽

pp. 3-10

Author(s):

B.S. Lomberg ◽

◽

O.A. Bazyleva ◽

M.M. Karashaev ◽

M.N. Letnikov ◽

...

Keyword(s):

High Temperature ◽

Heat Resistance ◽

Gas Turbine ◽

Room Temperature ◽

Structural Materials ◽

Turbine Engine ◽

Specific Strength ◽

New Class ◽

High Specific Strength ◽

Rotary Parts

A generalization of the results of scientific and technical publications is presented, the analysis of which will allow to develop scientific foundations for the creation of a new class of heat-resistant structural materials based on intermetallic matrices with increased plasticity at room temperature and high specific strength at temperatures up to 950 °C in the Ni–Al–Co system. It is shown that alloys of the Ni–Al–Co system can be used in the manufacture of rotary parts in the form of gas turbine engine discs (GTE), working at temperatures up to 950 °C, as well as materials for GTE blades due to heat resistance at temperatures up to 1200 °C.

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Validation of ATI 20-25+Nb™ Alloy at 50,000 Hours in the Recuperator of a Gas Turbine Engine

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

10.1115/gt2012-68163 ◽

2012 ◽

Author(s):

M. D. Bender ◽

J. M. Rakowski ◽

M. D. Lipschutz

Keyword(s):

High Temperature ◽

Gas Turbine ◽

Field Test ◽

Gas Turbine Engine ◽

Test Program ◽

Temperature Oxidation ◽

Turbine Engine ◽

Alloy 625 ◽

Turbine Exhaust

A field test program to validate high temperature oxidation resistance of the ATI 20-25+Nb™ alloy in a Solar Turbines Incorporated Mercury™ 50 gas turbine engine has exceeded 50,000 operating hours. A primary goal of this program is to assess the effect of the actual recuperator operating environment on high temperature degradation of primary surface recuperator (PSR) materials. As PSRs are generally fabricated from thin foil materials, excessive degradation can cause perforation, leading to failure of components. To avoid such problems, PSRs are generally fabricated from nickel-base superalloys or highly-alloyed austenitic stainless steels. Previously, ATI 20-25+Nb (UNS S35140) stainless steel was developed and experimentally shown to have excellent creep resistance and good environmental resistance for a PSR application. This field test program evaluates the long-term performance of this alloy in situ in turbine exhaust and compares it with the more highly alloyed Ni-based 625 superalloy. Sub-size air cell samples of alloy 625 and ATI 20-25+Nb alloy exposed for 50,000 hours (running time) in turbine exhaust were removed and tested for materials characterization. Analysis showed that both alloy 625 and ATI 20-25+Nb alloy exhibit excellent long-term resistance to environmental degradation, even after service exposure equivalent to over 5.5 years.

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Comparison of Ni-Based 625 Alloy and ATI 20-25+Nb™ Stainless Steel Foils After Long-Term Exposure to Gas Turbine Engine Exhaust

Volume 1B: Marine; Microturbines, Turbochargers and Small Turbomachines; Steam Turbines ◽

10.1115/gt2014-25334 ◽

2014 ◽

Cited By ~ 1

Author(s):

M. D. Bender ◽

R. C. Klug

Keyword(s):

Stainless Steel ◽

High Temperature ◽

Gas Turbine ◽

Field Test ◽

Gas Turbine Engine ◽

Test Program ◽

Temperature Oxidation ◽

Turbine Engine ◽

Turbine Exhaust

A field test program to validate the high temperature oxidation resistance of the ATI 20-25+Nb™ alloy in a Solar Turbines Incorporated Mercury™ 50 gas turbine engine has exceeded 66,000 operating hours. The primary goal of this program is to assess the effect of the actual recuperator operating environment on the high temperature degradation of primary surface recuperator (PSR) materials. As PSRs are generally fabricated from thin foil materials, excessive degradation can cause perforation or collapse, leading to decreased performance or failure. To avoid such issues, PSRs are generally fabricated from highly-alloyed austenitic stainless steels or nickel-base superalloys. This field test program evaluates and compares the long-term performance of the iron-based austenitic ATI 20-25+Nb™ stainless steel (UNS S35140) with the more highly alloyed nickel-based 625 alloy (UNS N06625) in an in-situ turbine exhaust environment. Sub-size air cell samples of alloy 625 and ATI 20-25+Nb™ alloy, exposed for 66,000 hours (running time) in turbine exhaust, were removed and tested for materials characterization. Analysis showed that both alloys exhibit excellent long-term resistance to environmental degradation, even after service exposures equivalent to over 7.5 years.

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