Cyclic Yield Behavior of Tantalum.

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)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1971
Accession Number
AD0728837

Entities

People

  • David R. Helebrant
  • Ralph I. Stephens

Organizations

  • University of Iowa

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Dislocations
  • Hardening
  • Mechanical Properties
  • Molybdenum
  • Physical Properties
  • Strain Hardening
  • Stress Strain Relations
  • Stresses
  • Tantalum
  • Vibration
  • Yield Strength

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.