Fracture Toughness / Fracture Energy Data for Ceramics

NIST Standard Reference Database 138

Last Update to Data Content: 1998



Reference: NIST Structural Ceramics Database

Other material collections: Property Data Summaries

Other Toughness materials

Calcium Fluoride ( CaF2 )

Material Summary:

                      [Ref. 1a]                [Ref. 1b]                [Ref. 1c, 2]        
Manufacturer........: Unknown                  Harshaw Co.              Eastman Kodak Co.
Material Designation: calcium fluoride;        calcium fluoride;        calcium fluoride;
                      also known as fluorspar  also known as fluorspar  also known as fluorspar
Material Form.......: Single Crystal           Polycrystal              Single Crystal
Composition.........: CaF2                     CaF2                     CaF2


[1] P. F. Becher and S. W. Freiman, "Crack Propagation in Alkaline-Earth Fluorides" Journal of Applied Physics, Vol. 49, No. 7, pp. 3779-3783 (1978).

[2] R. W. Rice, S. W. Freiman, and J. J. Mecholsky, "The Dependence of Strength-Controlling Fracture Energy on the Flaw-Size to Grain-Size Ratio" Journal of the American Ceramic Society, Vol. 63, No. 3-4, pp. 129-136 (1980).

Property Table:

Temperature = 23 °C
Grain    Porosity    Fracture      Fracture   Measurement  Measurement  Comments
Size                 Toughness     Energy     Method       Environment
[µm]       [%]       [MPa·m1/2]     [J/m2] 
------   --------   ------------   ---------  -----------  -----------  --------------------------------
                                    0.51        AMDCB          air       Ref. 1a Crack plane {111} and
                                                                                 crack direction [1-1c]
                                    0.51        AMDCB                    Ref. 1a Crack plane {111}
                                                                                 crack direction [1-1c]; 12Eu
                                    0.80        AMDCB                    Ref. 1a Material unannealed and crack
                                                                                 plane {111}, crack direction [112]
                                    0.52        AMDCB                    1,a Material annealed and gamma-crack
                                                                                 plane {111}, crack direction [112]
                                    1.6         AMDCB                    Ref. 1b Material hot worked and crack
                                                                                 plane {111}
50-100                              3.6         AMDCB                    Ref. 1c Material hot pressed and crack
                                                                                 plane n{111}
75         0.1                      3.3         AMDCB          air       Ref. 2; hot pressed material.