Mechanisms of fatigue crack propagation and fracture toughness behavior in advanced aluminum-lithium alloys

Technical Report · Wed Jun 01 04:00:00 EDT 1988

OSTI ID:6231296

Venkateswara Rao, K T

Mechanisms and mechanics influencing the fatigue crack propagation and plain-stain fracture toughness behavior commercial aluminum-lithium alloys are investigated as a function of the microstructure and plate orientation, both at ambient and liquid nitrogen temperatures. With ultra-low density, improved elastic modulus and high strength, in comparison to existing 7XXX and 2XXX alloys, the alloys additionally exhibit superior long (/approx gt/ 10 mm) fatigue crack properties, even after prolonged exposures at high temperatures, excel under tension-dominated spectrum loading and in some instances show superior fracture toughness values at ambient and liquid nitrogen temperatures. However, the properties are strongly dependent on plate orientation; moreover, the benefits of lithium additions are not realized for small (2--1000 ..mu..m) fatigue cracks. 260 refs., 72 figs., 11 tabs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6231296
• Report Number(s): LBL-26449; ON: DE89008300
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CRACK PROPAGATION
CRYSTAL STRUCTURE
DATA
FATIGUE
FRACTURE PROPERTIES
GRAIN SIZE
INFORMATION
LITHIUM ALLOYS
LITHIUM BASE ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NUMERICAL DATA
SIZE
TESTING