NIST Structural Ceramics Database (SCD) Database

NIST Standard Reference Database 30

Last Update to Data Content: 2002

DOI: http://dx.doi.org/10.18434/T4F30D


SCD Citation Number: Z00627

Bibliographic Information

Reference:
"Thermal Expansion of Reference Materials: Tungsten and α-Al2O3," G.K. White and R.B. Roberts, High Temperatures - High Pressures, Vol. 15, pp. 321-328 (1983), published by Pion Limited.
Language: English

General Materials Processing Notes

"The CODATA Task Group on Thermophysical Properties is preparting a set of recommended values for the thermal expansion... This paper deals with the expansion of... α-alumina from 10 K to 2000 K. Mean values are tabulated and new measurements are reported for alumina from 10 K to 300 K. ... There is no evidence that α is affected by trace impurities except at liquid helium temperature where magnetic ions may produce Schottky-type anomalies." The authors combined data from nine different studies to produce a set of recommended values.

Measurement Methods

Analysis
"Alpha-alumina (corundum, sapphire) has axial symmetry and hence two principal coefficients of expansion, αc (parallel to the c-axis) and αab (perpendicular to the c-axis). At arbitrary angle ϑ, αϑ = αab (sin ϑ)2 + αc (cos ϑ)2 . The volume coefficient, β, is given by β = 2 αab + αc. The average linear coefficient, αav, is β/3 and equals αϑ when ϑ is about 55°. ... We have used this fact to adjust report α values from ϑ = 60°, 59°, ... to the 'average' at ϑ = 55°."

Index of Materials and Properties

Material Number 1: Al2O3

Material Specification and Properties for Al2O3

Material number 1 of 1
in SCD Citation Number: Z00627
Chemical Class: Oxide
Chemical Family: Al-O
Formula: Al2O3
Informal Name: alumina
Structure Type: Single Crystal
Manufacturer: Typical
Process: Crystal Growth

Al2O3

Material number 1 of 1
in SCD Citation Number: Z00627
Thermal Expansion
Crystal
Direction
 
Temperature
 
( K )
Thermal
Expansion
( 10-6 K-1 )
c-axis 20 0.006
c-axis 30 0.022
c-axis 40 0.054
c-axis 50 0.120
c-axis 60 0.22
c-axis 70 0.35
c-axis 80 0.52
c-axis 90 0.73
c-axis 100 0.98
c-axis 120 1.52
c-axis 140 2.14
c-axis 160 2.72
c-axis 180 3.30
c-axis 200 3.84
c-axis 250 5.01
c-axis 293 5.80
c-axis 300 5.90
c-axis 350 6.50
c-axis 400 7.08
c-axis 450 7.57
c-axis 500 7.94
c-axis 550 8.30
c-axis 600 8.55
c-axis 650 8.79
c-axis 700 8.97
c-axis 800 9.29
c-axis 900 9.54
c-axis 1000 9.70
ab-plane 20 0.003
ab-plane 30 0.013
ab-plane 40 0.039
ab-plane 50 0.08
ab-plane 60 0.16
ab-plane 70 0.26
ab-plane 80 0.40
ab-plane 90 0.57
ab-plane 100 0.73
ab-plane 120 1.15
ab-plane 140 1.64
ab-plane 160 2.15
ab-plane 180 2.70
ab-plane 200 3.21
ab-plane 250 4.27
ab-plane 293 5.06
ab-plane 300 5.15
ab-plane 350 5.77
ab-plane 400 6.36
ab-plane 450 6.81
ab-plane 500 7.19
ab-plane 550 7.50
ab-plane 600 7.72
ab-plane 650 7.93
ab-plane 700 8.10
ab-plane 800 8.36
ab-plane 900 8.65
ab-plane 1000 8.83
mean 20 0.004
mean 30 0.016
mean 40 0.044
mean 50 0.095
mean 60 0.18
mean 70 0.29
mean 80 0.44
mean 90 0.61
mean 100 0.81
mean 120 1.28
mean 140 1.80
mean 160 2.34
mean 180 2.90
mean 200 3.42
mean 250 4.52
mean 293 5.30
mean 300 5.40
mean 350 6.08
mean 400 6.64
mean 450 7.10
mean 500 7.46
mean 550 7.75
mean 600 7.99
mean 650 8.18
mean 700 8.35
mean 800 8.62
mean 900 8.86
mean 1000 9.09
mean 1100 9.34
mean 1200 9.59
mean 1300 9.85
mean 1400 10.09
mean 1500 10.31
mean 1600 10.51
mean 1700 10.67
mean 1800 10.84
mean 1900 11.05
mean 2000 11.37

Measurement Method: Analysis
Evaluation Status: Evaluated by acceptance criteria
Cautions:
Cumulative expansion from 293 K. α(T) = [1/L(293)] [L(T) - L(293)]/[T - 293]