Accession Number : AD0481871

Title :   GRAIN SIZE DEPENDENCE OF FRACTURE OF ALPHA-COPPER ALUMINIUM ALLOYS IN MERCURY.

Descriptive Note : Technical rept.,

Corporate Author : MCMASTER UNIV HAMILTON (ONTARIO) DEPT OF METALLURGY AND METALLURGICAL ENGINEE RING

Personal Author(s) : Pargeter, F. W. J. ; Ives, M. B.

Report Date : APR 1966

Pagination or Media Count : 47

Abstract : Polycrystalline specimens of alpha-phase copper-aluminum alloys of varying composition, amalgamated with mercury, have been deformed in tension in a soft tensile machine. In all cases, brittle intergranular failure occurred at stresses and strains below those required for fracture in air, the degree of embrittlement increasing with increasing aluminum content. The alloys having stacking fault energies less than 8 ergs/sq cm were found to obey the Petch-Stroh relation. The other alloys showed negative deviations from this relation, particularly for large grain sizes, which became more marked with increasing stacking fault energy. Values of the fracture energy have been obtained for all the alloys; they vary from 48 ergs/sq cm for pure copper, to 470 ergs/sq cm for Cu-8 wt.% Al. These values are only applicable for relatively small grain sizes. A model is proposed to explain the deviation from the Petch-Stroh relation in the high-stacking-fault-energy alloys. (Author)

Descriptors :   *STRESSES), *STRAIN(MECHANICS)), (*BRITTLENESS, (*EMBRITTLEMENT, ALUMINUM ALLOYS, COPPER ALLOYS, MERCURY ALLOYS, FRACTURE(MECHANICS), ENERGY, CRYSTALS, TENSILE PROPERTIES, PROPAGATION, GRAIN SIZE, ROLLING(METALLURGY), SURFACES, FAILURE(MECHANICS), AIR, MERCURY, LOADS(FORCES), METALLOGRAPHY, LIQUID METALS.

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE