Accession Number:

AD0701106

Title:

THE EFFECT OF ENVIRONMENT ON THE MECHANICAL BEHAVIOR OF materials.

Descriptive Note:

Annual rept. Jan-Dec 69,

Corporate Author:

MARTIN MARIETTA CORP DENVER COLO DENVER DIV

Personal Author(s):

• Kramer,Irvin R.

Report Date:

1970-01-01

Pagination or Media Count:

35.0

Abstract:

The cyclic creep behavior of aluminum 7075-T6 and titanium 6Al4V was investigated in air and in vacuum. The cyclic creep decreased in vacuum. The kinetics for the relaxation of the surface layer stress in copper appear to follow a first-order reaction rate with respect to the surface layer stress. The apparent activation energy for the process is 3340 calories per mole. This low activation energy can be accounted for by a driving force imposed by the surface layer. The behavior of copper and titanium in media that cause stress corrosion cracking was investigated. These media caused the surface layer stress to increase appreciably. A tentative theory for stress corrosion is suggested. Author

Descriptors:

• (*ALUMINUM ALLOYS
• CREEP)
• (*TITANIUM ALLOYS
• CREEP)
• COPPER
• STRESSES
• HEAT OF ACTIVATION
• VANADIUM ALLOYS
• STRESS CORROSION
• REACTION KINETICS
• VACUUM

Subject Categories:

• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE