Development of New Generation Turbine Disk Superalloys in the HTM21 Project

2007 ◽  
Vol 546-549 ◽  
pp. 1277-1280
Author(s):  
Yue Feng Gu ◽  
C. Cui ◽  
D. Ping ◽  
Hiroshi Harada ◽  
Akihiro Sato ◽  
...  

A new kind of cast & wrought (C&W) Ni-Co base superalloys named as “TMW alloys” was developed recently for compressor and turbine disk of gas turbine engines in the High Temperature Materials 21 Project at the National Institute for Materials Science (NIMS) in Japan. These Ni-Co base superalloys combine the characters of two kinds of γ- γ’ two-phase alloys (Ni-base and Co-base superalloys) and can be fabricated by cheap cast and wrought processing route. The results showed that some of these TMW alloys have superior tensile strength at temperatures up to 750 °C and higher creep resistances up to 725 °C than commercial UDIMET 720 LI alloy.

Author(s):  
E. N. Kablov ◽  
Yu. A. Bondarenko ◽  
M. Yu. Kolodyazhny ◽  
V. A. Surova ◽  
A. R. Narsky

The paper presents the scientific, technical and technological aspects in the field of creating new high-temperature materials for parts of the hot section of gas turbine engines (GTE) with operating temperatures exceeding those existing in GTE. More refractory metallic materials for the creation of new high-heat-resistant alloys used for the manufacture of rotor and nozzle blades and other parts of promising gas turbine engines based on NiAl-Ni3Al, Co-Cr-Re, Pt-Al, Nb-Si, Mo-Si-B systems have been investigated. It is shown that, depending on the composition of the selected matrix, the working temperature of heat-resistant alloys increases to 1300-1500°С, which is significantly higher than the existing nickel heat-resistant alloys.


Author(s):  
M R Winstone ◽  
A Partridge ◽  
J W Brooks

Improvements in the performance and efficiency of gas turbine engines have been intimately linked to the development of materials technologies for the high-temperature components. This paper reviews some of the recent research that will ensure that the engines for the next generation of aircraft deliver world class performance at an affordable cost.


Alloy Digest ◽  
1999 ◽  
Vol 48 (7) ◽  

Abstract Haynes alloy 75 is an 80 nickel-20 chromium alloy with both good oxidation resistance and good mechanical properties at high temperatures. It is amenable to all forms of fabrication and welding. A typical application for sheet metal is fabrications in gas turbine engines. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming and heat treating. Filing Code: Ni-557. Producer or source: Haynes International Inc.


Author(s):  
Hooshang Heshmat ◽  
James F. Walton

Abstract To achieve high power density Gas Turbine Engines (GTEs), R&D efforts have strived to develop machines that spin faster and run hotter. One method to achieve that goal is to use high temperature capable foil bearings. In order to successfully integrate these advanced foil bearings into GTE systems, a theoretical understanding of both bearing and rotor system integration is essential. Without a fundamental understanding and sound theoretical modeling of the foil bearing coupled with the rotating system such an approach would prove application efforts fruitless. It is hoped that the information provided in this paper will open up opportunistic doors to designs presently thought to be impossible. In this paper an attempt is made to describe how an advanced foil bearing is modeled for extreme high temperature operation in high performance turbomachinery including GTEs, Supercritical CO2 turbine generators and others. The authors present the advances in foil bearing capabilities that were crucial to achieving high temperature operation. Achieving high performance in a compliant foil bearing under the wide extremes of operating temperatures, pressures and speeds, requires a bearing system design approach that accounts for the highly interrelated compliant surface foil bearing elements such as: the structural stiffness and frictional characteristics of the underlying compliant support structure across the operating temperature and pressure spectrum; and the coupled interaction of the structural elements with the hydrodynamic pressure generation. This coupled elasto-hydrodynamic-Finite Element highly non-linear iterative methodology will be used by the authors to present a series of foil bearing design evaluations analyzing and modeling the foil bearing under extreme conditions. The complexity of the problem of achieving foil bearing system operation beyond 870°C (1600°F) requires as a prerequisite the attention to the tribological details of the foil bearing. For example, it is necessary to establish how both the frictional and viscous damping coefficient elements as well as the structural and hydrodynamic stiffness are to be combined. By combining these characteristics the influence of frictional coefficients of the elastic and an-elastic materials on bearing structural stiffness and hence the bearing effective coupled elasto-hydrodynamic stiffness coefficients will be shown. Given that the bearing dynamic parameters — stiffness and damping coefficients — play a major role in the control of system dynamics, the design approach to successfully integrate compliant foil bearings into complex rotating machinery systems operating in extreme environments is explored by investigating the effects of these types of conditions on rotor-bearing system dynamics. The proposed rotor/bearing model is presented to describe how system dynamics and bearing structural properties and operating characteristics are inextricably linked together in a manner that results in a series separate but intertwined iterative solutions. Finally, the advanced foil bearing modeling and formulation in connection with resulting rotor dynamics of the system will be carried out for an experimental GTE simulator test rig. The analytical results will be compared with the experiments as presented previously to demonstrate the effectiveness of the developed method in a real world application [1].


2011 ◽  
Vol 278 ◽  
pp. 405-410 ◽  
Author(s):  
Alexander Devaux ◽  
Eric Georges ◽  
Philippe Héritier

The enhancement of efficiency in gas turbine engines requires the development of new superalloys capable of withstanding higher temperatures. The development of novel industrial cast and wrought (C&W) disk alloys with required combination of strength, creep and fatigue resistances at 700°C is particularly desired due to the expensive cost of powder metallurgy. In this context, new C&W disk alloys were recently developed to fulfill these requirements. TMW4 shows higher properties than the current C&W disk alloy despite an expensive cost due to its high cobalt content, where as 718Plus presents a moderate cost with restricted creep properties at 700°C compared to the current U720Li disk alloy. The new nickel base superalloys developed by Aubert & Duval were therefore designed to offer a better compromise between high temperature properties at 700°C and cost. This paper describes the alloy metallurgical features and is especially focused on the alloy design which is extensively based on phase diagram modeling. The study was firstly carried out on small ingots of 6 kg to optimize the chemistry before forging 200 kg ingots by industrial processes. The ability to be processed by the conventional cast & wrought route and the control of the highly expensive elements contents confer to the alloys an attractive cost comparable to that of 718Plus alloy. The high amount of ’ and the molybdenum-tungsten levels insure higher creep and tensile properties than those obtained with 718Plus.


Author(s):  
Hooshang Heshmat ◽  
James F. Walton

The objective of this investigation is to develop a novel powder-lubricated rotor bearing system damper concept for use in high-temperature, high-speed rotating machinery such as advanced aircraft gas turbine engines. The approach discussed herein consists of replacing a conventional oil lubrication or frictional damper system with a powder lubrication system that uses the process particulates or externally-fed powder lubricant. Unlike previous work in this field, this approach is based on the postulate of the quasi-hydrodynamic nature of powder lubrication. This postulate is deduced from past observation and present verification that there are a number of basic features of powder flow in narrow interfaces that have the characteristic behavior of fluid film lubrication. In addition to corroborating the basic mechanism of powder lubrication, the conceptual and experimental work performed in this program provides guidelines for selection of the proper geometries, materials and powders suitable for this tribological process. The present investigation describes the fundamentals of quasi-hydrodynamic powder lubrication and defines the rationale underlying the design of the test facility. The performance and the results of the experimental program present conclusions reached regarding design requirements as well as the formulation of a proper model of quasi-hydrodynamic powder lubrication.


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