On the Nucleation and Growth of Alpha-Ti Off of TiB Precipitates (PREPRINT)

Abstract

We have investigated the microstructure of the beta-stabilized Ti-15Mo-2.6Nb-3Al-0.2Si-0.12B alloy at two different aging temperatures, 540 degrees C/8 hr and 660 degrees C/8 hr. At the lower aging temperature, alpha-Ti precipitated as needle-like shapes off of the TiB phase. In contrast, the higher aged sample exhibited globular alpha-Ti morphology around the TiB phase. This difference has been rationalized by the coarsening behavior of alpha-Ti around the TiB phase. Various orientation relationships were observed between these two samples. This difference is because the precipitation of alpha-Ti off of two different TiB planes. In addition, atom probe analysis confirmed the segregation of alpha and beta stabilizing elements to the respective phases. It was noted that silicon enriched the alpha-Ti/beta-Ti interface at the lower aged temperature where as this enrichment was observed at the alpha-Ti/TiB interface at the higher aged temperature.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2010
Accession Number
ADA520988

Entities

People

  • Bo Fu
  • Gregory B. Thompson
  • J. S. Tiley
  • K. Torres
  • R. Srinivasan
  • Taisuke Sasaki

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Contrast
  • Diffraction
  • Electron Microscopes
  • Electron Microscopy
  • Engineering
  • Grain Boundaries
  • Heat Treatment
  • Materials
  • Materials Engineering
  • Materials Science
  • Mechanical Properties
  • Microscopes
  • Microscopy
  • Microstructure
  • Precipitation

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Mathematics or Statistics