Quantitative Evaluation of Alitize Coating on ŽS6K Ni-Base Superalloy

2014 ◽  
Vol 782 ◽  
pp. 578-583 ◽  
Author(s):  
Juraj Belan
Keyword(s):  
Turbine Blades ◽  
Advanced Materials ◽  
Diffusion Annealing ◽  
Jet Engines ◽  
Unique Combination ◽  
Jet Engine ◽  
Working Temperature ◽  
Aerospace Applications ◽  
Mechanical And Physical Properties ◽  
Base Superalloy

The aerospace industry is one of the biggest consumers of advanced materials because of its unique combination of mechanical and physical properties and chemical stability. Highly alloyed stainless steel, titanium alloys and nickel based superalloys are mostly used for aerospace applications. The aim of the work is to evaluate protective Al Si coating applied by diffusion annealing on substrate, Ni base superalloy ZS6K. This superalloy is used for turbine blade production in aero jet engine DV 2. Using of protective alitize coating provides an increasing of heat resistance of superalloy surface and increases working temperature up to 800°C. However, overcrossing of working temperature range (for ZS6K turbine blades it is from 705°C to 750°C) sometimes happen and that is the reason for detailed study of protective coating degradation. The alitize coating were evaluated in starting stage and after various time of regular loading in real aero jet engines DV 2. Coating and its degradation was evaluated with help of quantitative metallography methods (metallography software NIS Elements) and colour contrast as well.

Fatigue Crack Growth Resistance of Advanced Blade Materials

1987 ◽  
Vol 109 (2) ◽  
pp. 176-181 ◽  
Author(s):  
D. A. Wilson ◽  
D. P. Deluca ◽  
B. A. Cowles ◽  
M. A. Stucke
Keyword(s):  
Crack Growth ◽  
Turbine Blades ◽  
Weight Ratio ◽  
Engine Performance ◽  
Advanced Materials ◽  
Effect Of Temperature ◽  
Crack Growth Behavior ◽  
Fatigue Crack Growth Resistance ◽  
Jet Engine ◽  
Measure Of Performance

The best measure of performance in a jet engine is the thrust-to-weight ratio. Cast single-crystal superalloys provide higher temperature capability and offer opportunities for significant improvements in future jet engine performance and durability. The highly anisotropic behavior of these advanced materials, which includes modulus, strength, and ductility variation with crystallographic orientation, pose potentially significant problems for design and life prediction of advanced turbine blades. The objective of this paper is to provide a better understanding of the crack growth behavior in this advanced turbine blade material by evaluating the effect of temperature, frequency, orientation, and thickness.

Model Based Control Concepts for Jet Engines

2001 ◽  
Author(s):  
Klaus Lietzau ◽  
Andreas Kreiner
Keyword(s):  
Turbine Blades ◽  
Engine Performance ◽  
Current Control ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Engine Model ◽  
Model Based ◽  
Safety Margins ◽  
Engine Life

Many jet engine variables cannot be measured in-flight or can only be measured with a complex, and hence unreliable, instrumentation system. This includes variables that are of imminent importance for the safe operation of the engine or for engine life, such as the temperature of the high pressure turbine blades or the surge margins of the turbo compressors, for instance. Current control systems therefore transform limits on these variables into limits on other variables measured by the engine’s sensors. This leads to increased safety margins and thus to non-optimal engine performance. An onboard engine model incorporated into the engine control system could provide information about all engine variables. This could enable further control and monitoring system optimisations leading to improved engine performance, reduced fuel consumption, increased safety and engine life. This paper explains the principle of model based engine control and gives an overview about possible applications for conventional and also thrust vectored jet engines. Modeling methods for real-time simulation as well as methods for online model adaptation are presented. The potential of model based jet engine control is analyzed and fortified by some prototype realizations.

Microstructural evolution of a nickel-based superalloy

1990 ◽  
Vol 48 (4) ◽  
pp. 936-937
Author(s):  
Waldemar A. Monteiro ◽  
Ingrid A. Dos Santos
Keyword(s):  
Turbine Blades ◽  
Nuclear Space ◽  
Structural Studies ◽  
Jet Engine ◽  
Microstructural Observation ◽  
Nickel Based Superalloy ◽  
Heat Treated ◽  
Turbine Disks ◽  
Nickel Base ◽  
Base Superalloy

Superalloys are indispensable for the superior perfomance and efficien of jet engine turbine disks,turbine blades,combustors,roket shells and many other devices and components used in various industries, in Cluding nuclear, space and aeronautics.Over the last thirty years,nickel-base superalloys has undergone more structural studies than any other superalloy as a result of attempts to correlate its properties to microstructure and heat treatment. To avoid contradictory or inconsistent findings, it is also necessary a carefully microstructural observation of the employed starting materials. In the present paper,we report morphologies relating to the as cast , forged and heat-treated Ni-base superalloy by transmission and scanning electron microscopy. This superalloy contain intermettallic compounds and carbides. The alloy in study was an as cast and also forged Ni-Fe based superalloy with the following chemical composition:

scholarly journals Fatigue Crack Growth Resistance of Advanced Blade Materials

1986 ◽  
Author(s):  
D. A. Wilson ◽  
D. P. Deluca ◽  
B. A. Cowles ◽  
M. A. Stucke
Keyword(s):  
Crack Growth ◽  
Turbine Blades ◽  
Weight Ratio ◽  
Engine Performance ◽  
Advanced Materials ◽  
Effect Of Temperature ◽  
Crack Growth Behavior ◽  
Fatigue Crack Growth Resistance ◽  
Jet Engine ◽  
Measure Of Performance

The best measure of performance in a jet engine is the thrust-to-weight ratio. Cast single-crystal superalloys provide higher temperature capability and offer opportunities for significant improvements in future jet engine performance and durability. The highly anistropic behavior of these advanced materials, which includes modulus, strength, and ductility variation with crystallographic orientation, pose potentially significant problems for design and life prediction of advanced turbine blades. The objective of this paper is to provide a better understanding of the crack growth behavior in this advanced turbine blade material by evaluating the effect of temperature, frequency, orientation, and thickness.

scholarly journals Superior Oxidation Resistance Titanium Alloy ARCONIC-THORTM for Aerospace Applications

2020 ◽  
Vol 321 ◽  
pp. 04013
Author(s):  
Sesh Tamirisakandala ◽  
Ernie Crist ◽  
Fusheng Sun ◽  
Matthew Dahar
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Cost Savings ◽  
Jet Engines ◽  
Aerospace Applications ◽  
Technology Advancement ◽  
Aerospace Systems ◽  
Material Systems ◽  
Nickel Base

Next generation fuel-efficient jet engines are running hotter presenting a structural challenge for the exhaust systems and structures adjacent to the engines. A conventional and affordable titanium alloy with superior oxidation resistance provides significant weight reductions and associated cost savings by eliminating the need for high density material systems such as nickel-base superalloys for service temperatures in between current titanium and nickel, enabling major technology advancement in high temperature aerospace applications. This paper presents an overview of Arconic’s engineered material ARCONIC-THORTM to address the needs of future aerospace systems.

Practical Bypass Mixing Systems for Fan Jet Aero Engines

1966 ◽  
Vol 17 (2) ◽  
pp. 141-160 ◽  
Author(s):  
T. H. Frost
Keyword(s):  
Gas Turbines ◽  
Minimum Weight ◽  
Jet Engines ◽  
Metal Interface ◽  
Combustion Chambers ◽  
Propulsion Systems ◽  
Jet Engine ◽  
Aero Engines ◽  
Corrugated Metal ◽  
Constant Static Pressure

SummaryMixing systems have many applications in gas turbines and aircraft jet propulsion, e.g. mixing zones in combustion chambers, ejectors for jet lift thrust augmentors and supersonic propulsion systems. A further application similar to that of combustion chamber mixing is that of mixing the cold and hot exhausts of a bypass jet engine. These are both characterised by mixing at constant static pressure and approximately constant total pressure as opposed to the more general case of unequal pressures in ejector systems (Fig. 1).The exhaust mixing process as used in Rolls-Royce bypass jet engines, e.g. Spey and Conway, enables the potential of the bypass principle, in terms of minimum weight and fuel consumption, to be exploited by a simple practical device.This is achieved by mixing the two streams in a common duct of fairly short dimensions with a corrugated metal interface on the inlet side. The consideration of these practical systems forms the main topic of this paper.

scholarly journals Towards Damage Controlled Hot Forming

2018 ◽  
Vol 885 ◽  
pp. 56-63
Author(s):  
Markus Bambach ◽  
Irina Sizova ◽  
Aliakbar Emdadi
Keyword(s):  
Metal Forming ◽  
High Performance ◽  
Titanium Aluminides ◽  
Turbine Blades ◽  
Process Time ◽  
Jet Engines ◽  
Internal Damage ◽  
Creep Properties ◽  
Recent Developments ◽  
Ram Speed

Metal forming processes may induce internal damage in the form of voids in the workpiece under unfavorable deformation conditions. Controlling the amount of damage induced by metal forming operations may increase service performance of the produced parts. Damage is crucial in high-performance components of limited workability such as jet engine turbine blades. Recent developments have introduced forged titanium aluminides into commercial jet engines. Titanium aluminides are lightweight intermetallic compounds with excellent creep properties but very limited ductility. Their low workability requires isothermal forging at slow strain rates, which is typically kept constant in the process. This work explores the possibility of increasing the ram speed during the process so that the process time is reduced while the amount of damage introduced into the workpiece is controlled. The results show that a 25% reduction in process time seems viable without increase in damage by solving an optimal control problem, in which the ram speed profile is determined off-line by minimization.

Design and Analysis of an Intentional Mistuning Experiment Reducing Flutter Susceptibility and Minimizing Forced Response of a Jet Engine Fan

2017 ◽  
Author(s):  
Felix Figaschewsky ◽  
Arnold Kühhorn ◽  
Bernd Beirow ◽  
Jens Nipkau ◽  
Thomas Giersch ◽  
...  
Keyword(s):  
Computational Model ◽  
Paint Layer ◽  
Forced Vibrations ◽  
Forced Response ◽  
Operating Conditions ◽  
Jet Engines ◽  
Jet Engine ◽  
Aspect Ratios ◽  
Engine Order ◽  
Stall Flutter

Recent demands for a reduction of specific fuel consumption of jet engines have been opposed by increasing propulsive efficiency with higher bypass ratios and increased engine sizes. At the same time the challenge for the engine development is to design safe and efficient fan blades of high aspect ratios. Since the fan is the very first rotor stage, it experiences significant distortions in the incoming flow depending on the operating conditions. Flow distortions do not only lead to a performance and stall margin loss but also to remarkable low engine order (LEO) excitation responsible for forced vibrations of fundamental modes. Additionally, fans of jet engines typically suffer from stall flutter, which can be additionally amplified by reflections of acoustic pressure waves at the intake. Stall flutter appears before approaching the stall line on the fan’s characteristic and limits its stable operating range. Despite the fact that this “flutter bite” usually affects only a very narrow speed range, it reduces the overall margin of safe operation significantly. With increasing aspect ratios of ultra-high bypass ratio jet engines the flutter susceptibility will probably increase further and emphasizes the importance of considering aeromechanical analyses early in the design phase of future fans. This paper aims at proving that intentional mistuning is able to remove the flutter bite of modern jet engine fans without raising issues due to heavily increased forced vibrations induced by LEO excitation. Whereas intentional mistuning is an established technology in mitigating flutter, it is also known to amplify the forced response. However, recent investigations considering aeroelastic coupling revealed that under specific circumstances mistuning can also reduce the forced response due to engine order excitation. In order to allow a direct comparison and to limit costs as well as effort at the same time, the intentional mistuning is introduced in a non-destructive way by applying heavy paint to the blades. Its impact on the blade’s natural frequencies is estimated via finite element models with an additional paint layer. In parallel, this procedure is experimentally verified with painted fan blades in the laboratory. A validated SNM (subset of nominal system modes) representation of the fan is used as a computational model to characterize its mistuned vibration behavior. Its validation is done by comparing mistuned mode shape envelopes and frequencies of an experimental modal analysis at rest with those obtained by the updated computational model. In order to find a mistuning pattern minimizing the forced response of mode 1 and 2 at the same time and satisfying stability and imbalance constraints, a multi-objective optimization has been carried out. Finally, the beneficial properties of the optimized mistuning pattern are verified in a rig test of the painted rotor.

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