Accession Number : AD0728837

Title :   Cyclic Yield Behavior of Tantalum.

Descriptive Note : Technical rept.,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Helebrant,David R. ; Stephens,Ralph I.

Report Date : AUG 1971

Pagination or Media Count : 26

Abstract : Previous investigations have shown the room temperature upper yield point stress of b.c.c. iron, molybdenum and niobium can be completely removed by initially 'elastic' fully-reversed cyclic stressing above the fatigue limit. The research described shows the upper yield point stress in tantalum can also be removed under these same conditions and is dependent upon the stress amplitude and the number of applied stress cycles. Aging at room temperature did not cause a return of the upper yield point. The cyclic stress-strain curve of tantalum cyclically strain softened at small strain amplitudes and cyclically strain hardened at larger amplitudes. Under constant cyclic strain amplitudes in the inealstic region, tantalum exhibited slight initial cyclic strain hardening. The cyclic yield point behavior is explained in terms of localized cumulative multiplication of mobile dislocations. (Author)

Descriptors :   (*TANTALUM, FATIGUE(MECHANICS)), TENSILE PROPERTIES, STRAIN(MECHANICS), HYSTERESIS, DISLOCATIONS

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE