Feasibility Study of Intermetallic Composites

1990 ◽  
Vol 194 ◽  
Author(s):  
D. M. Shah ◽  
D. L. Anton ◽  
C. W. Musson

AbstractThe feasibility of developing high-temperature intermetallic composites for use as gas turbine engine components is assessed for a wide range of high temperature intermetallic matrices including aluminides, silicides, Laves and Sigma phases along with Al2O3, SiC, TiC, Si3N4 and Y2O3 as well as ductile refractory metals as either reinforcing phases or coatings. Preliminary evaluations of fabricability and observations of matrix/reinforcing phase compatibility are presented and discussed in terms of various factors, including interstitial impurities, equilibrium phase relationships, kinetics, and physical and mechanical properties of both matrix and reinforcing phases.

Author(s):  
Brian Keyes ◽  
Jeffrey Brogan ◽  
Christopher Gouldstone ◽  
Robert Greenlaw ◽  
Jie Yang ◽  
...  

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

In this paper, the authors present the results of recent developments demonstrating that ultra-high temperature compliant foil bearings are suitable for application in a wide range of high temperature turbomachinery including gas turbine engines, supercritical CO2 power turbines and automotive turbochargers as supported by test data showing operation of foil bearings at temperatures to 870°C (1600°F). This work represents the culmination of efforts begun in 1987, when the U.S. Air Force established and led the government and industry collaborative Integrated High Performance Turbine Engine Technology (IHPTET) program. The stated goal of IHPTET was to deliver twice the propulsion capability of turbine engines in existence at that time. Following IHPTET, the Versatile Affordable Advanced Turbine Engines (VAATE) program further expanded on the original goals by including both versatility and affordability as key elements in advancing turbine engine technology. Achieving the stated performance goals would require significantly more extreme operating conditions including higher temperatures, pressures and speeds, which in turn would require bearings capable of sustaining temperatures in excess of 815°C (1500°F). Similarly, demands for more efficient automotive engines and power plants are subjecting the bearings in turbochargers and turbogenerators to more severe environments. Through the IHPTET and VAATE programs, the U.S. has made considerable research investments to advancing bearing technology, including active magnetic bearings, solid and vapor phase lubricated rolling element bearings, ceramic/hybrid ceramic bearings, powder lubricated bearings and compliant foil gas bearings. Thirty years after the IHPTET component goal of developing a bearing capable of sustained operation at temperatures above 540°C and potentially as high as 815°C (1500°F) recent testing has demonstrated achievement of this goal with an advanced, ultra-high temperature compliant foilgas bearing. Achieving this goal required a combination of high temperature foil material, a unique elastic-tribo-thermal barrier coating (KOROLON 2250) and a self-adapting compliant configuration. The authors describe the experimental hardware designs and design considerations of the two differently sized test rigs used to demonstrate foil bearings operating above 815°C (1500°F). Finally, the authors present and discuss the results of testing at temperatures to 870°C (1600°F).


Author(s):  
J. R. Palmer ◽  
Yong-Gen Gu

This paper presents a computer model called ‘TURBOTEST’ which is applicable both to analysis of gas turbine engine rig tests and to simulation of engine steady-state performance. As with the earlier ‘TURBOFLEXI’ model a wide range of gas turbine engines can be simulated, using any kind of hydrocarbon fuel, and allowing for chemical dissociation of the gas, and for the effect of air humidity. In addition, however, for the particular requirements of rig test analysis, the following new features have been developed and incorporate:- (a) It can carry out rig test analysis for a wide range of gas turbine engines if all the necessary test data are presented. (b) If the test data is incomplete, a computer simulation of the engine can be used to complete the analysis. (c) Performance deterioration of engine components can be detected by comparing the results of a test analysis and of a parallel simulation using stored characteristics of engine components in the “as new” condition. The program has been tested on simulated test data generated by engine models such as a turbojet and a turbofan. The results show it has close and repeatable agreement with design values. Further tests of the model have been carried out by applying it to the actual engine rig test data.


Author(s):  
Orlov Maksim Andreyevich Et al.

The article discusses the features of the destruction of carbon fiber reinforced plastics on the basis of tfp-preforms produced using various stitching mode parameters, and provides for studies of their physical and mechanical properties and structure. The effect of the carbon fiber laying density and the piercing step of the aramid yarn on the elastic-strength properties of composites is shown. The optimal technological parameters for creating tfp-preforms of gas turbine engine blades were chosen.


2021 ◽  
pp. 1-11
Author(s):  
Jacob Elms ◽  
Alison Pawley ◽  
Nicholas Bojdo ◽  
Merren Jones ◽  
Rory J. Clarkson

Abstract The ingestion of multi-mineral dusts by gas turbine engines during routine operations is a significant problem for engine manufacturers because of the damage caused to engine components and their protective thermal barrier coatings. A complete understanding of the reactions forming these deposits is limited by a lack of knowledge of compositions of ingested dusts and unknown engine conditions. Past engine tests have used standardised test dusts that do not resemble the composition of the background dust in the operating regions. A new evaporite-rich test dust was developed and used in a full engine ingestion test, designed to simulate operation in regions with evaporite-rich geology, such as Doha or Dubai. Analysis of the engine deposits showed that mineral fractionation was present in the cooler, upstream sections of the engine. In the hotter, downstream sections, deposits contained new, high temperature phases formed by reaction of minerals in the test dust. The mineral assemblages in these deposits are similar to those found from previous analysis of service returns. Segregation of anhydrite from other high temperature phases in a deposit sample taken from a High Pressure Turbine blade suggests a relationship between temperature and sulfur content. This study highlights the potential for manipulating deposit chemistry to mitigate the damage caused in the downstream sections of gas turbine engines. The results of this study also suggest that the concentration of ingested dust in the inlet air may not be a significant contributing factor to deposit chemistry.


Author(s):  
H. A. Johnson ◽  
G. K. Bhat

At the present time, virtually all superalloys used in Soviet gas turbine engines have been electroslag remelted. The use of this process in the United States has been at a virtual standstill since its inception by Hopkins in 1935. This paper will cover recent development effort on the process and what it offers to the industry. The process itself will be described in detail. Included also will be its advantages, both in metalworking and resultant mechanical properties obtained on actual gas turbine engine components fabricated from electroslag remelted superalloys.


Author(s):  
Jacob Elms ◽  
Alison Pawley ◽  
Nicholas Bojdo ◽  
Merren Jones ◽  
Rory Clarkson

Abstract The ingestion of multi-mineral dusts by gas turbine engines during routine operations is a significant problem for engine manufacturers because of the damage caused to engine components and their protective thermal barrier coatings. A complete understanding of the reactions forming these deposits is limited by a lack of knowledge of compositions of ingested dusts and unknown engine conditions. Test bed engines can be dosed with dusts of known composition under controlled operating conditions, but past engine tests have used standardised test dusts that do not resemble the composition of the background dust in the operating regions. A new evaporiterich test dust was developed and used in a full engine ingestion test, designed to simulate operation in regions with evaporiterich geology, such as Doha or Dubai. Analysis of the engine deposits showed that mineral fractionation was present in the cooler, upstream sections of the engine. In the hotter, downstream sections, deposits contained new, high temperature phases formed by reaction of minerals in the test dust. The mineral assemblages in these deposits are similar to those found from previous analysis of service returns. Segregation of anhydrite from other high temperature phases in a deposit sample taken from a High Pressure Turbine blade suggests a relationship between temperature and sulfur content. This study highlights the potential for manipulating deposit chemistry to mitigate the damage caused in the downstream sections of gas turbine engines. The results of this study also suggest that the concentration of ingested dust in the inlet air may not be a significant contributing factor to deposit chemistry.


1992 ◽  
Author(s):  
KIRK D ◽  
ANDREW VAVRECK ◽  
ERIC LITTLE ◽  
LESLIE JOHNSON ◽  
BRETT SAYLOR

Sign in / Sign up

Export Citation Format

Share Document