Cyclic Fatigue Behaviour at Room Temperature and at High Temperature under Inert Atmosphere of a C/SiC Multilayer Composite

1998 ◽  
Vol 164-165 ◽  
pp. 325-328 ◽  
Author(s):  
A. Dalmaz ◽  
Pascal Reynaud ◽  
Dominique Rouby ◽  
Gilbert Fantozzi ◽  
M. Bourgeon
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Cyclic Fatigue ◽  
Fatigue Behaviour ◽  
Inert Atmosphere ◽  
Multilayer Composite

Comparisons of cyclic fatigue hysteresis between C/SiC and SiC/SiC ceramic–matrix composites with different fiber preforms at room and elevated temperatures

2020 ◽  
Vol 54 (20) ◽  
pp. 2723-2737
Author(s):  
Li Longbiao
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Ceramic Matrix Composites ◽  
Cyclic Fatigue ◽  
Inert Atmosphere ◽  
Dissipated Energy ◽  
Matrix Composites ◽  
Cycle Number ◽  
Air Atmosphere ◽  
Sic Ceramic

In this paper, the cyclic fatigue hysteresis of carbon fiber reinforced silicon carbide (C/SiC) and SiC/SiC ceramic–matrix composites with different fiber preforms at room and elevated temperatures is investigated. The evolution of fatigue hysteresis dissipated energy versus applied cycle number for unidirectional C/SiC ( σmax = 240 MPa at room temperature and σmax = 250 MPa at 800℃ in air atmosphere), cross-ply C/SiC ( σmax = 105 MPa at room temperature and 800℃ in air atmosphere), 2D C/SiC ( σmax = 387 and 425 MPa at room temperature), 2.5D C/SiC ( σmax = 180 MPa at room temperature, σmax = 140 MPa at 800℃ in air atmosphere, and σmax = 230 MPa at 600℃ in inert atmosphere), 2D SiC/SiC ( σmax = 130 MPa at 600℃, 800℃, and 1000℃ in inert atmosphere, σmax = 80 MPa at 1000℃ in air atmosphere, σmax = 100 MPa at 1000℃ in steam atmosphere, σmax = 140 MPa at 1200℃ in air and in steam atmospheres, σmax = 90, 120 MPa at 1300℃ in air atmosphere), and 3D SiC/SiC ( σmax = 100 MPa at 1300℃ in air atmosphere) is analyzed. The change rate of the fatigue hysteresis dissipated energy between C/SiC and SiC/SiC composites is compared. The fatigue hysteresis dissipated energy decreases with applied cycle number for unidirectional, and cross-ply C/SiC composite at 800℃ in air, and 2.5D C/SiC composite at 600℃ in inert; and the fatigue hysteresis dissipated energy increases with applied cycle number for 2.5D C/SiC composite at 800℃ in air, 2D SiC/SiC composite at 600℃, and 800℃ in inert.

Fatigue and Creep Behaviour of a SiCf/SiC Composite for Nuclear Fusion Reactor Applications

2006 ◽  
Vol 45 ◽  
pp. 1444-1449
Author(s):  
E. Trentini ◽  
B. Riccardi ◽  
M. Labanti
Keyword(s):  
High Temperature ◽  
Creep Strain ◽  
Room Temperature ◽  
Creep Behaviour ◽  
Rupture Life ◽  
Peak Load ◽  
Fatigue Behaviour ◽  
Mechanical Tests ◽  
Time To Failure ◽  
Nuclear Fusion Reactor

This study presents the results of mechanical tests of commercial 2D SiCf/SiC ceramic matrix composite for fusion reactors applications. The creep behaviour was investigated by means of flexural constant load stress-rupture tests, in controlled atmosphere at 600 and 1000°C. The creep strain and time to failure vary with applied load according to a power law. Cyclical tests at room temperature and at high temperature showed that the material has a good fatigue behaviour at room temperature, as no evident fatigue damage was detected after 80.000 cycles at a peak load up to 98 % of MOR. Conversely at high temperature (1000°C) the specimens showed a progressive compliance increase and limited cycles to failure even at peak load as low as 40 % of MOR. Creep phenomena seem to influence the fatigue behaviour. Creep strain analysis, crack growth and fracture surface observations allowed to investigate the mechanisms that affect the crack propagation, the fracture process and the rupture life under cyclic loading and under constant stress loading at different temperatures.

Fatigue Behaviour of Structural Ceramic Composites

2006 ◽  
Vol 45 ◽  
pp. 1664-1673 ◽  
Author(s):  
Gilbert Fantozzi ◽  
Pascal Reynaud ◽  
Dominique Rouby
Keyword(s):  
High Temperature ◽  
Mechanical Behaviour ◽  
Slow Crack Growth ◽  
Cyclic Fatigue ◽  
Fatigue Behaviour ◽  
Ceramic Composites ◽  
Self Healing ◽  
New Generation ◽  
Oxide Composites

Non-oxide composites are interesting materials for long term applications at high temperature under oxidizing atmosphere. To improve their lifetime, self-healing [Si-B-C] matrix has been developed recently. On this new generation of composite, fatigue has been studied at high temperature (up to 1200°C) in air. For the SiCf/[Si-B-C] composite, lifetime at 600°C is higher than 1000 h for a tension/compression cyclic loading of -50/+170 MPa. Nevertheless, the mechanical behaviour during the cyclic fatigue test is different at 600°C from that at 1200°C. Contrarily to 1200°C, at 600°C no specific evolution of the classical parameters used to characterize the mechanical behaviour during fatigue allows us to estimate the approach to fracture,. This indicates that the fatigue phenomena involved at 600°C are different from those involved at 1200°C. At 600°C, lifetime is mainly controlled by slow-crack-growth in the fibres in presence of air, and at 1200°C lifetime is controlled by fibre creep and oxidation.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

MAGNESIUM AZ31B

Alloy Digest ◽  
1962 ◽  
Vol 11 (9) ◽  
Keyword(s):  
High Temperature ◽  
Magnesium Alloy ◽  
Physical Properties ◽  
Room Temperature ◽  
Heat Treating ◽  
General Purpose ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Wrought Magnesium Alloy ◽  
Metal Products

Abstract Magnesium AZ31B is a general purpose wrought magnesium alloy for room temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Mg-53. Producer or source: The Dow Metal Products Company.

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