FACTORS CONTROLLING RESISTANCE TO DEFORMATION AND MECHANICAL FAILURE IN POLYCRYSTALLINE (GLASS-FREE) CERAMICS. Period covered: July 1, 1957 to December 15, 1958. Project title: SOLID STATE RESEARCH AND PROPERTIES OF MATTER. Task title: MECHANISMS AND DEFORMATION BEHAVIOR OF SOLIDS

Technical Report · Fri May 01 04:00:00 EDT 1959

OSTI ID:4183409

Wachtman, Jr, J B; Tefft, W E; Lam, Jr, D G; Stinchfield, R P

The elastic mcduli and internal friction of several refractory oxide materials were studied. The six elastic constants of sapphire were measured with particular care and the results were found to differ from previously accepted values for four of these constants. Young's mcdulus for single crystal sapphire was found to decrease linearly with increasing temperature above 100 tained C. As the temperature was decreased below l00 tained C, Young's mcdulus first rose above the extrapolated high temperature straight line and then tended to become constant. The internal friction of single crystal sapphire was found to vary from 5 x 10/sup -5/ to 3 x 10/sup -6/ at rccm temperature. Anneaiing below 500 tained C decreased the value in a specimen with initially high damping. An internal friction peak was found in polycrystalline alumina with 15% lanthanum oxide additive. Young's mcdulus of uranium dioxide was measured as a function of temperature. Two intennal friction peaks were found in polycrystalline zirconium oxide stabilized with 5% calcium oxide. These results are discussed. (auth)

• Research Organization: National Bureau of Standards, Washington, D.C.
• NSA Number: NSA-14-019443
• OSTI ID: 4183409
• Report Number(s): WADC-TR-59-278; PB-161112
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM OXIDES
ANNEALING
CALCIUM OXIDES
CERAMICS
CONTROL
CRYSTALS
DEFORMATION
ELASTICITY
FAILURES
FRICTION
LANTHANUM OXIDES
MEASURED VALUES
MECHANICAL PROPERTIES
METALS, CERAMICS, AND OTHER MATERIALS
MONOCRYSTALS
QUANTITY RATIO
REFRACTORIES
SAPPHIRE
SOLIDS
STABILITY
TEMPERATURE
URANIUM DIOXIDE
VARIATIONS
YOUNG MODULUS
ZIRCONIUM OXIDES