ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 4

Evaluation of Fracture Energy of Aluminum Alloys

Johnson, FA
Research officer and research fellow, Imperial College of Science and Technology, London,

Radon, JC
Research officer and research fellow, Imperial College of Science and Technology, London,

Abstract

The fracture toughnesses of some precipitation-hardened aluminum alloys have been evaluated, mainly by the use of precracked three-point bend specimens in instrumented impact testing. A recently developed interpretation of the specific surface energy method has been applied to calculate the initiation values of K_Ic and these values have been compared with those calculated using stress analysis equations. The value of unity thereby deduced for the geometrical constraint factor in these non-rate-sensitive materials may be appropriate to the type of fracture mode occurring in these alloys, that is, semiductile. The distinction in principle between fracture initiation toughness, expressed as G_Ic = w/ηA, and the average propagation toughness w/A has been noted and the latter used in studying crack tunnelling during semiductile crack propagation in thick sections of the alloys in the form of large, double-cantilever beam specimens.

Keywords:
aluminum alloys, fracture strength, impact tests, toughness, crack propagation, stress strain diagrams, fracture energy

Paper ID: JTE10176J
DOI: 10.1520/JTE10176J
ASTM International is a member of CrossRef.