Accession Number : AD0716787

Title :   The Influence of Oxygen Concentration on the Internal Stress and Dislocation Arrangements in Alpha Titanium.

Descriptive Note : Technical rept.,

Corporate Author : NORTH AMERICAN ROCKWELL CORP LOS ANGELES CALIF LOS ANGELES DIV

Personal Author(s) : Sommer,A. W. ; Tung,P. P.

Report Date : OCT 1970

Pagination or Media Count : 26

Abstract : The long range and thermally activated components of the flow stress in alpha-Ti have been measured by a stress relaxation technique. Materials containing five different levels of oxygen, ranging from 250-5200 weight ppm were studied over the temperature range 200K-550K. The dislocation arrangements after relaxation have also been studied using thin foil electron microscopy techniques. In the higher oxygen materials it has been found that the internal stress varies more strongly with temperature than would be predicted by the temperature dependence of the elastic modulus; simultaneously, the thermally activated component of the flow stress goes through a maximum at the temperature where the internal stress becomes strongly temperature dependent. Thin foil results show that the maximum flow stress and rise of internal stress correspond to the onset of coplanar slip. An attempt to qualitatively rationalize this behavior is also made. (Author)

Descriptors :   (*TITANIUM, STRESSES), (*DISLOCATIONS, TITANIUM), CREEP, OXYGEN, TEMPERATURE, ELECTRON MICROSCOPY

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE