Accession Number:

ADA250282

Title:

Strengthening Mechanisms, Creep and Fatigue Processes in Dispersion Hardened Niobium Alloy

Descriptive Note:

Final technical rept. 1 Feb 1989-31 Jan 1992

Corporate Author:

CALIFORNIA UNIV DAVIS DIV OF MATERIALS SCIENCE AND ENGINEERING

Report Date:

1992-04-01

Pagination or Media Count:

57.0

Abstract:

The creep and fatigue properties of pure Nb and Nb-lZr alloy were investigated. A model was developed based on the migration of subgrain boundary that can explain the anomalous primary creep transients found in Nb-lZr alloy, due to coarsening of subgrain structure. TEM investigations confirmed that such subgrain coarsening occurs during primary creep of Nb-lZr. Baseline low cycle fatigue studies of Nb and Nb-lZr were completed. Cyclic hardening is observed and there is a microplastic plateau in Nb. The Nb-1Zr is stronger in cyclic deformation than Nb, with little influence of strain rate. The deformation in the alloy at both high and low strain rates is controlled by the interaction between gliding edge dislocation and solute atoms. Creep, fatigue, niobium alloy, dislocation mechanisms.

Subject Categories:

  • Metallurgy and Metallography
  • Crystallography
  • Mechanics
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE