Author: Richard E. Tressler
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
The great advantages, in terms of economy and performance, to be gained by using high performance ceramics in applications such as the gas turbine engine have spurred development efforts in the non-oxide ceramic area and in hardware applications. However, relatively little effort has been devoted to examining in detail the factors which may limit lifetimes in the above applications in which long lifetimes have been traditionally demanded. The purpose of this research project was to use a fundamentally based fracture mechanics approach to examine the susceptibility of Si3N4 and SiC ceramics to stress-corrosion in water and various gaseous environments over a range of temperatures. Further, the fundamental mechanism(s) which contribute(s) to the observed slow crack growth were to be elucidated. In addition, an effort was initiated to investigate the mechanism(s) by which molten salt environments may limit strengths and lifetimes of these materials. (Author).
Environmental Effects Upon the Time-Dependent Fracture of Silicon Nitride and Silicon Carbide
Author: Richard E. Tressler
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
The great advantages, in terms of economy and performance, to be gained by using high performance ceramics in applications such as the gas turbine engine have spurred development efforts in the non-oxide ceramic area and in hardware applications. However, relatively little effort has been devoted to examining in detail the factors which may limit lifetimes in the above applications in which long lifetimes have been traditionally demanded. The purpose of this research project was to use a fundamentally based fracture mechanics approach to examine the susceptibility of Si3N4 and SiC ceramics to stress-corrosion in water and various gaseous environments over a range of temperatures. Further, the fundamental mechanism(s) which contribute(s) to the observed slow crack growth were to be elucidated. In addition, an effort was initiated to investigate the mechanism(s) by which molten salt environments may limit strengths and lifetimes of these materials. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
The great advantages, in terms of economy and performance, to be gained by using high performance ceramics in applications such as the gas turbine engine have spurred development efforts in the non-oxide ceramic area and in hardware applications. However, relatively little effort has been devoted to examining in detail the factors which may limit lifetimes in the above applications in which long lifetimes have been traditionally demanded. The purpose of this research project was to use a fundamentally based fracture mechanics approach to examine the susceptibility of Si3N4 and SiC ceramics to stress-corrosion in water and various gaseous environments over a range of temperatures. Further, the fundamental mechanism(s) which contribute(s) to the observed slow crack growth were to be elucidated. In addition, an effort was initiated to investigate the mechanism(s) by which molten salt environments may limit strengths and lifetimes of these materials. (Author).
Environmental Effects on the Time Dependent Failure of Non-Oxide Ceramics
Author: Richard E. Tressler
Publisher:
ISBN:
Category :
Languages : en
Pages : 197
Book Description
The mechanical and chemical factors that contribute to time dependent strength changes have been investigated for a variety of non-oxide materials including silicon nitride, silicon carbide and siliconized silicon carbide. The flaw behavior in an as-machined and oxidized HIP'ed silicon nitride under static load was investigated at various stress intensities, times, and temperatures. Flaw origins were of the pore/cavity and iron-based inclusion type. There was no strength increase or degradation in as-machined and oxidized samples static loaded for ten hours at 1100 C in air below the threshold stress intensity. The threshold stress intensity for crack growth at 1100 C were determined to be 1.75 and 2.00 MPa.m1/2 for the as-machined and oxidized HIPSN, respectively. A strength decrease with increased applied stress was observed in as-machined specimens static loaded at 1200 C and 1300 C in air. This effect is due to the creation of a new flaw population with more severe flaws. Keywords: Silicon nitride, Silicon carbide, Oxidation, High temperature strength, Threshold stress intensity, Slow crack growth, Tensile creep behavior, Cavitation, Creep damage. (JES).
Publisher:
ISBN:
Category :
Languages : en
Pages : 197
Book Description
The mechanical and chemical factors that contribute to time dependent strength changes have been investigated for a variety of non-oxide materials including silicon nitride, silicon carbide and siliconized silicon carbide. The flaw behavior in an as-machined and oxidized HIP'ed silicon nitride under static load was investigated at various stress intensities, times, and temperatures. Flaw origins were of the pore/cavity and iron-based inclusion type. There was no strength increase or degradation in as-machined and oxidized samples static loaded for ten hours at 1100 C in air below the threshold stress intensity. The threshold stress intensity for crack growth at 1100 C were determined to be 1.75 and 2.00 MPa.m1/2 for the as-machined and oxidized HIPSN, respectively. A strength decrease with increased applied stress was observed in as-machined specimens static loaded at 1200 C and 1300 C in air. This effect is due to the creation of a new flaw population with more severe flaws. Keywords: Silicon nitride, Silicon carbide, Oxidation, High temperature strength, Threshold stress intensity, Slow crack growth, Tensile creep behavior, Cavitation, Creep damage. (JES).
Research in Progress
Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 834
Book Description
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 834
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 300
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 300
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 672
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 672
Book Description
Inventory of energy research and development--1973-1975
Author: Oak Ridge National Laboratory
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 1356
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 1356
Book Description
Inventory of Energy Research and Development, 1973-1975: Indexes and appendices
Author: Oak Ridge National Laboratory
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 1462
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 1462
Book Description
Corrosion Abstracts
Author:
Publisher:
ISBN:
Category : Corrosion and anti-corrosives
Languages : en
Pages : 722
Book Description
Publisher:
ISBN:
Category : Corrosion and anti-corrosives
Languages : en
Pages : 722
Book Description
World Survey of Current Research and Development on Roads and Road Transport
Author: International Road Federation
Publisher:
ISBN:
Category : Highway research
Languages : en
Pages : 520
Book Description
Publisher:
ISBN:
Category : Highway research
Languages : en
Pages : 520
Book Description
Department of the Interior and Related Agencies Appropriations for 1990: Economic Regulatory Administration
Author: United States. Congress. House. Committee on Appropriations. Subcommittee on Department of the Interior and Related Agencies
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 814
Book Description
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 814
Book Description