FACTORS AFFECTING THE HIGH TEMPERATURE STRENGTH OF POLYCRYSATLLINE SOLIDS

Technical Report · Fri Dec 01 00:00:00 EST 1961

OSTI ID:4800308

Sherby, O D

Quantitative analyses of the high temperature strength data (70.5Tm) on pure polycrystalline metals indicate that factors which will promote the high temperature creep resistance include crystal structure; the best structure is the diamond type, followed by the close-packed FCC or HCP and lastly, the BCC structure. Other factors are high melting temperature, high elastic modulus, high valence state, and fine stable grain size. Comparison of current theories of high temperature deformation with experimental data reveals that Weertman's theory of creep based on dislocation climb best describes the experimental data for creep of pure metals at high stresses and the NabarroHerring theory based on atomic diffusion appears applicable at low stresses. The role of stable discontinuous precipitates on high temperature creep is not clearly understood, and their role on the creep strength of sintered Al powder is probably only of secondary importance. (auth)

• Research Organization: Stanford Univ., Calif.
• DOE Contract Number: AF33(616)-6789
• NSA Number: NSA-16-012085
• OSTI ID: 4800308
• Report Number(s): ARL-101
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-62
• Country of Publication: United States
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
ALUMINUM
ATOMS
CREEP
CRYSTALS
DEFECTS
DEFORMATION
DIAMONDS
DIFFUSION
DISLOCATIONS
ELASTICITY
ELECTRONS
GRAIN SIZE
HIGH TEMPERATURE
IMPURITIES
LATTICES
MATERIALS TESTING
MEASURED VALUES
MELTING
MELTING POINTS
METALS
POWDERS
PRECIPITATION
QUALITATIVE ANALYSIS
SINTERED MATERIALS
SINTERING
SOLIDS
STABILITY
STANDARDS
STRESSES
TEMPERATURE
TENSILE PROPERTIES
VALENCE