Accession Number:

ADA171881

Title:

A Differential Scanning Calorimetry Study of Guinier Preston Zone Formation and Dissolution in 7075 and 7091 Aluminum Alloys.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLOGY DIRECTORATE

Personal Author(s):

• Frazier,William

Report Date:

1985-12-30

Pagination or Media Count:

23.0

Abstract:

The aging behavior of PM 7091 and IM 7075 aluminum were studied by DSC also hardness and conductivity. The energy associated with the formation and dissolution of Guinier Preston zones is correlated to mechanical and physical properties equations for conductivity and hardness as a function of heat of reaction are presented. The activation energy fo GP dissolution was established by differential scanning calorimetry DSC and values for delta H, deltaG, and deltaS were calculated using absolute reaction rate theory. The activation energy calculated for GP disolution in 7075-T6 is equivalent to the activation energy reported for the diffusion of Zn in aluminum.

Descriptors:

• *ALUMINUM ALLOYS
• SCANNING
• PHYSICAL PROPERTIES
• THERMODYNAMICS
• ENERGY
• EXTRUSION
• HIGH STRENGTH ALLOYS
• ELECTRICAL CONDUCTIVITY
• POWDER METALLURGY
• SUPERSATURATION
• SOLID SOLUTIONS
• HARDNESS
• CALORIMETERS
• ZINC ALLOYS
• HEAT OF REACTION

Subject Categories:

• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE