THERMAL PROPERTIES OF Β-Silicon CARBIDE FROM 20 TO 2000°C

Kern, E. L.; Hamill, D.W.; Deem, H.W.; Sheets, H. D.

doi:10.1016/b978-0-08-006768-1.50007-3

Cited by 19 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rezaie et al [7] and Watts et al [8] used linear elastic fracture mechanics to show that critical flaw sizes correlated to the SiC cluster size in ZrB 2 -30 vol% SiC ceramics. This conclusion is consistent with the CTE mismatch between ZrB 2 and SiC (for α-SiC: α a-axis = 4.3 × 10 −6 K −1 , α c-axis = 4.7 × 10 −6 K −1 ) [55]. Watts et al [56] used neutron diffraction to measure the thermal residual stresses present in ZrB 2 -30 vol% SiC.…”

Section: Size Effect Of Sic Additionsupporting

confidence: 57%

Mechanical Properties of Zirconium‐Diboride Based UHTCs

Neuman

Hilmas

2014

Ultra‐High Temperature Ceramics

View full text Add to dashboard Cite

Section: Size Effect Of Sic Additionsupporting

confidence: 57%

Mechanical Properties of Zirconium‐Diboride Based UHTCs

Neuman

Hilmas

2014

Ultra‐High Temperature Ceramics

View full text Add to dashboard Cite

“…The difference in CTE values between the two axes within the hexagonal crystal structure results in a ∼95 MPa thermal stress within polycrystalline ZrB 2 when cooled from a typical processing temperature (1900°C) 157 . The addition of α‐SiC (6H) particles results in larger thermal stresses in ZrB 2 –SiC than in polycrystalline ZrB 2 due to the lower CTE of SiC (4.7 × 10 −6 and 4.3 × 10 −6 K −1 along the c ‐ and a ‐axis, respectively) 158 . An Eshelby analysis () of ZrB 2 containing SiC‐particulates, assuming spherical SiC inclusions, predicts radial compressive stresses within the ZrB 2 matrix to be as high as 2.1 GPa and tangential tensile stresses of 4.2 GPa at ZrB 2 –SiC interfaces 159 : where m denotes the matrix, i denotes the inclusion, α is the CTE, ν is Poisson's ratio and E is Young's modulus.…”

Section: Microstructure and Mechanical Propertiesmentioning

confidence: 99%

“…157 The addition of a-SiC (6H) particles results in larger thermal stresses in ZrB 2 -SiC than in polycrystalline ZrB 2 due to the lower CTE of SiC (4.7 Â 10 À6 and 4.3 Â 10 À6 K À1 along the c-and a-axis, respectively). 158 An Eshelby analysis (Eq. (12)) of ZrB 2 containing SiC-particulates, assuming spherical SiC inclusions, predicts radial compressive stresses within the ZrB 2 matrix to be as high as 2.1 GPa and tangential tensile stresses of 4.2 GPa at ZrB 2 -SiC interfaces 159 :…”

Section: Microstructure and Mechanical Propertiesmentioning

confidence: 99%

Refractory Diborides of Zirconium and Hafnium

Fahrenholtz

Talmy

Zaykoski

2007

Journal of the American Ceramic Society

1,822

1,134

View full text Add to dashboard Cite

This paper reviews the crystal chemistry, synthesis, densification, microstructure, mechanical properties, and oxidation behavior of zirconium diboride (ZrB2) and hafnium diboride (HfB2) ceramics. The refractory diborides exhibit partial or complete solid solution with other transition metal diborides, which allows compositional tailoring of properties such as thermal expansion coefficient and hardness. Carbothermal reduction is the typical synthesis route, but reactive processes, solution methods, and pre‐ceramic polymers can also be used. Typically, diborides are densified by hot pressing, but recently solid state and liquid phase sintering routes have been developed. Fine‐grained ZrB2 and HfB2 have strengths of a few hundred MPa, which can increase to over 1 GPa with the addition of SiC. Pure diborides exhibit parabolic oxidation kinetics at temperatures below 1100°C, but B2O3 volatility leads to rapid, linear oxidation kinetics above that temperature. The addition of silica scale formers such as SiC or MoSi2 improves the oxidation behavior above 1100°C. Based on their unique combination of properties, ZrB2 and HfB2 ceramics are candidates for use in the extreme environments associated with hypersonic flight, atmospheric re‐entry, and rocket propulsion.

show abstract

“…A SiC density of 3.1 g cm À3 , [44] a C density of 2.26 g cm À3 , [45] and a SiO 2 density of 2.65 g cm À3 [46] were assumed. The two models examine fibers with either constant phase areas or constant phase thicknesses, respectively.…”

Section: Fiber Composition Effects On Parabolic Oxidationmentioning

confidence: 99%

A Review of SiC Fiber Oxidation with a New Study of Hi‐Nicalon SiC Fiber Oxidation

Wilson

Opila

2016

Adv Eng Mater

View full text Add to dashboard Cite

The linear and parabolic oxidation rate constants and activation energies for SiC fibers available in the literature are reviewed for the first time. Oxidation experiments are also conducted with Hi-Nicalon SiC fibers over 700-1 300 C in dry O 2 with thermogravimetric analysis. Linear oxidation kinetics are observed from 700 to 800 C and parabolic kinetics are observed from 900 to 1 300 C. The linear and parabolic oxidation rate constant activation energies are determined to be 83 and 108 kJ mol À1 , respectively. These kinetic results are compared with the literature values. Differences in oxidation behavior are assessed as a function of fiber composition.

show abstract

THERMAL PROPERTIES OF Β-Silicon CARBIDE FROM 20 TO 2000°C

Cited by 19 publications

References 0 publications

Mechanical Properties of Zirconium‐Diboride Based UHTCs

Mechanical Properties of Zirconium‐Diboride Based UHTCs

Refractory Diborides of Zirconium and Hafnium

A Review of SiC Fiber Oxidation with a New Study of Hi‐Nicalon SiC Fiber Oxidation

Contact Info

Product

Resources

About