Prediction of the Strength of Ceramic Tubular Components: Part II — Experimental Verification

1991 ◽  
Author(s):  
D. L. Shelleman ◽  
O. M. Jadaan ◽  
J. C. Conway ◽  
J. J. Mecholsky
Keyword(s):  
Silicon Carbide ◽  
Statistical Theory ◽  
Room Temperature ◽  
Strength Distribution ◽  
Ring Test ◽  
Stress Distributions ◽  
Pressure Test ◽  
Tubular Components ◽  
Tubular Specimens ◽  
Strength Distributions

Abstract The strength distribution of reaction bonded silicon carbide tubes that failed by internal pressurization was predicted from strength distributions obtained from simple laboratory test specimens at room temperature. The strength distributions of flexure bars, C-rings tested in tension, C-rings tested in compression, diametrally compressed O-rings, and internally pressurized short tubes were compared to the strength distribution of internally pressurized long tubes. The methodology involved application of Weibull statistical theory using elasticity theory to define the stress distributions in the simple specimens. The flexural specimens did not yield acceptable results, since they were ground prior to testing, thereby altering their flaw population in comparison with the processing induced flaw populations of the tubular specimens. However, the short tube internal pressure test, the c-ring tested in tension and the diametrally compressed o-ring test configurations yielded accurate predictions, since these specimens more accurately represent the strength limiting flaw population in the long tubes.

Effect of multiaxial stresses on the fracture strength of silicon carbide

1969 ◽  
Vol 4 (2) ◽  
pp. 81-87 ◽  
Author(s):  
E K Priddle
Keyword(s):  
Silicon Carbide ◽  
Fracture Strength ◽  
Room Temperature ◽  
Fracture Behaviour ◽  
Axial Tension ◽  
Straight Line ◽  
Failure Envelopes ◽  
Tension And Compression ◽  
Failure Theories ◽  
Tubular Specimens

This work describes the fracture behaviour of silicon-carbide tubular specimens under multi-axial stresses at room temperature. A method of obtaining combinations of stresses in the form of torsion, hoop, axial tension, and compression is described and failure envelopes for silicon carbide are included from the data obtained. Failure theories are reviewed and the results from the work show that the available theories are inadequate to describe both the tension-tension and tension-compression quadrants. For practical purposes a straight-line relation can be used joining axial and hoop tensile strengths and the axial compression strength.

scholarly journals Reliability Analysis of Uniaxially Ground Brittle Materials

1996 ◽  
Vol 118 (4) ◽  
pp. 863-871 ◽  
Author(s):  
J. A. Salem ◽  
N. N. Nemeth ◽  
L. M. Powers ◽  
S. R. Choi
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Fracture Strength ◽  
Mixed Mode ◽  
Strength Distribution ◽  
Principal Stress Direction ◽  
Reliability Models ◽  
Machining Damage ◽  
Fast Fracture ◽  
Strength Distributions

The fast fracture strength distribution of uniaxially ground, alpha silicon carbide was investigated as a function of grinding angle relative to the principal stress direction in flexure. Both as-ground and ground/annealed surfaces were investigated. The resulting flexural strength distributions were used to verify reliability models and predict the strength distribution of larger plate specimens tested in biaxial flexure. Complete fractography was done on the specimens. Failures occurred from agglomerates, machining cracks, or hybrid flaws that consisted of a machining crack located at a processing agglomerate. Annealing eliminated failures due to machining damage. Reliability analyses were performed using two and three-parameter Weibull and Batdorf methodologies. The Weibull size effect was demonstrated for machining flaws. Mixed mode reliability models reasonably predicted the strength distributions of uniaxial flexure and biaxial plate specimens.

scholarly journals Reliability Analysis of Uniaxially Ground Brittle Materials

1995 ◽  
Author(s):  
Jonathan A. Salem ◽  
Noel N. Nemeth ◽  
Lynn M. Powers ◽  
Sung R. Choi
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Fracture Strength ◽  
Mixed Mode ◽  
Strength Distribution ◽  
Principal Stress Direction ◽  
Reliability Models ◽  
Machining Damage ◽  
Fast Fracture ◽  
Strength Distributions

The fast fracture strength distribution of uniaxially ground, alpha silicon carbide was investigated as a function of grinding angle relative to the principal stress direction in flexure. Both as-ground and ground/annealed surfaces were investigated. The resulting flexural strength distributions were used to verify reliability models and predict the strength distribution of larger plate specimens tested in biaxial flexure. Complete fractography was done on the specimens. Failures occurred from agglomerates, machining cracks, or hybrid flaws that consisted of a machining crack located at a processing agglomerate. Annealing eliminated failures due to machining damage. Reliability analyses were performed using two and three parameter Weibull and Batdorf methodologies. The Weibull size effect was demonstrated for machining flaws. Mixed mode reliability models reasonably predicted the strength distributions of uniaxial flexure and biaxial plate specimens.

Fabrication and Testing of Plasma-Spray Formed MoSi2 and MoSi2 Composite Tubes

1993 ◽  
Vol 322 ◽  
Author(s):  
R.G. Castro ◽  
J.R. Hellmann ◽  
A.E. Segall ◽  
D.L. Shelleman
Keyword(s):  
Plasma Spray ◽  
Room Temperature ◽  
Heat Treating ◽  
Spray Forming ◽  
Strength Distribution ◽  
Thick Wall ◽  
Plasma Spray Forming ◽  
Plasma Sprayed ◽  
Mosi2 Composite ◽  
Tubular Components

AbstractPlasma-spray forming has been used to fabricate thick-wall tubes of Mosi2 and Mosi2 containing concentric layers of A12O3. This process is being investigated as a potential fabrication method for producing tubular components of Mosi2 and Mosi2 composites for use in high temperature fuel-burner applications. Results will be reported on the spray forming method used to produce tubes of various sizes. The room temperature strength of pure Mosi2 tubes in the as-deposited condition, and after heat-treating at 1500 °C for 2 hours in vacuum, will also be reported. The strength of plasma sprayed Mosi2 tubes were measured via diametral compression of 0-ring and C-ring sections in air at room temperature. Qualification of the strength distribution was based on Weibull statistical theory.

Prediction of the Strength of Ceramic Tubular Components: Part I — Analysis

1991 ◽  
Author(s):  
O. M. Jadaan ◽  
D. L. Shelleman ◽  
J. C. Conway ◽  
J. J. Mecholsky ◽  
R. E. Tressler
Keyword(s):  
Statistical Theory ◽  
Internal Pressure ◽  
Failure Prediction ◽  
Strength Distribution ◽  
Effective Volume ◽  
Structural Components ◽  
Diametral Compression ◽  
Point Bend ◽  
Tubular Components ◽  
Tubular Shape

Abstract The objective of this paper is to develop the analytical background for test methodologies that will enable accurate prediction of the strength distribution of ceramic tubular components from the strength distributions of simple specimens. Four simple specimen configurations and two tubular configurations were selected for this purpose. The simple specimen configurations were (1) four point bend, (2) c-ring tested in compression, (3) c-ring tested in tension and (4) o-ring tested in diametral compression. In addition, a short tube tested by axially compressing rubber inside the tube and a long tube subjected to internal pressure were analyzed. These specimen configurations were for the most part selected in a tubular shape in order to simulate the shape of tubular structural components. The prediction of the strength distribution of one specimen from that of another was based on Weibull statistical theory. Effective volume and area expressions, necessary for failure prediction, were derived for these specimen configurations.

High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

2019 ◽  
Vol 12 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yuchen Deng ◽  
Yaming Zhang ◽  
Nanlong Zhang ◽  
Qiang Zhi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Grain Size ◽  
Phase Composition ◽  
Room Temperature ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Substrate ◽  
Sic Ceramics ◽  
Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

Fast Selective Sensing of Nitrogen-Based Gases Utilizing δ-MnO2-Epitaxial Graphene-Silicon Carbide Heterostructures for Room Temperature Gas Sensing

2020 ◽  
Vol 29 (5) ◽  
pp. 846-852
Author(s):  
Michael D. Pedowitz ◽  
Soaram Kim ◽  
Daniel I. Lewis ◽  
Balaadithya Uppalapati ◽  
Digangana Khan ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Room Temperature ◽  
Gas Sensing ◽  
Epitaxial Graphene

Silicon Carbide Die Attach Scheme for 500°C Operation

2000 ◽  
Vol 622 ◽  
Author(s):  
Liang-Yu Chen ◽  
Gary W. Hunter ◽  
Philip G. Neudeck
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Semiconductor Devices ◽  
Single Crystal Silicon ◽  
Film Material ◽  
Crystal Silicon ◽  
Pure Alumina ◽  
Die Attach

ABSTRACTSingle crystal silicon carbide (SiC) has such excellent physical, chemical, and electronic properties that SiC based semiconductor electronics can operate at temperatures in excess of 600°C well beyond the high temperature limit for Si based semiconductor devices. SiC semiconductor devices have been demonstrated to be operable at temperatures as high as 600°C, but only in a probe-station environment partially because suitable packaging technology for high temperature (500°C and beyond) devices is still in development. One of the core technologies necessary for high temperature electronic packaging is semiconductor die-attach with low and stable electrical resistance. This paper discusses a low resistance die-attach method and the results of testing carried out at both room temperature and 500°C in air. A 1 mm2 SiC Schottky diode die was attached to aluminum nitride (AlN) and 96% pure alumina ceramic substrates using precious metal based thick-film material. The attached test die using this scheme survived both electronically and mechanically performance and stability tests at 500°C in oxidizing environment of air for 550 hours. The upper limit of electrical resistance of the die-attach interface estimated by forward I-V curves of an attached diode before and during heat treatment indicated stable and low attach-resistance at both room-temperature and 500°C over the entire 550 hours test period. The future durability tests are also discussed.

Fatigue Reliability Functions in Semilogarithmic Coordinates

1991 ◽  
Author(s):  
Vladimir A. Avakov
Keyword(s):  
Fatigue Life ◽  
Coordinate System ◽  
Strength Distribution ◽  
Fatigue Reliability ◽  
Life Distribution ◽  
Similar Transformation ◽  
Asymptotic Type ◽  
Life Distributions ◽  
Strength Distributions

Abstract In the previous publication [2], the transformation between fatigue life and strength distribution was established using double-logarithmic coordinate system (lnN-lnS). Here, a similar transformation is established using a semi logarithmic (lnN-S) coordinate system. With the aid of the developed orthogonal relations, lognormal, Weibull and three-parameter logweibull life distributions have been transformed into normal, asymptotic type 1 of smallest value, and three-parameter Weibull strength distributions, respectively. This procedure may be applied to other types of fatigue life distribution.

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