Cyclic Yield Behavior of Polycrystalline Niobium.

Abstract

Previous investigations showed that the room temperature upper and lower yield point stress of b.c.c. iron and molybdenum can be completely removed by initially 'elastic' cyclic stressing above the fatigue limit. The research described shows the upper and lower yield point stress in niobium can also be removed under these same conditions. The cyclic stress-strain curve of niobium was found to cyclically strain soften at small strain amplitudes and cyclically strain harden at larger strains. Under constant cyclic strain amplitudes in the inelastic region niobium cyclically strain hardens and quickly reaches a stable hysteresis loop. The described cyclic yield point behavior was explained in terms of localized cumulative multiplication of mobile dislocations. (Author)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1970
Accession Number
AD0714819

Entities

People

  • Ralph I. Stephens
  • Satish K. Agrawal

Organizations

  • University of Iowa

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Dislocations
  • Hysteresis
  • Mechanical Properties
  • Military Vehicles
  • Molybdenum
  • Physical Properties
  • Polycrystals
  • Stress Strain Relations
  • Stresses
  • Vehicles
  • Vibration
  • Yield Strength

Readers

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