Accession Number : AD0488129

Title :   THE RELATIONSHIP BETWEEN PLASTIC DEFORMATION AND FRACTURE IN ALPHA TITANIUM.

Descriptive Note : Summary rept. Jun 65-Jun 66,

Corporate Author : TRW EQUIPMENT GROUP CLEVELAND OH MATERIALS RESEARCH AND DEVELOPMENT DEPT

Personal Author(s) : Amateau, M. F. ; Steigerwald, E. A.

Report Date : JUN 1966

Pagination or Media Count : 51

Abstract : Crack initiation and propagation behavior was studied in unalloyed titanium containing between 0.25 and 0.6% oxygen and in Ti-5Al-2.5Sn alloy containing between 0.07 and 0.37% oxygen. Large-grained tensile specimens were tested at -320 F and metallographically examined to identify the mechanism of microcrack formation. Precracked single edge notched specimens were tested at -320 F in order to relate crack propagation events to fracture energy and grain orientation. Second order twin induced microcracking, which is responsible for brittle behavior in unalloyed titanium at 0.25% oxygen, becomes restricted at 0.5 and 0.6% oxygen. In Ti-5Al-2.5Sn alloy containing 0.3% oxygen, slip induced microcracks form in addition to twin induced microcracks. A general correlation was found between fracture energy, grain orientation and crack propagation events in unalloyed titanium containing 0.25 to 0.6% oxygen. (Author)

Descriptors :   (*TITANIUM, FRACTURE(MECHANICS)), (*TITANIUM ALLOYS, FRACTURE(MECHANICS)), PLASTIC PROPERTIES, OXYGEN, ALUMINUM ALLOYS, TIN ALLOYS, CRYSTAL DEFECTS, DEFORMATION.

Subject Categories : Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE