Microstructure, tensile, and creep behavior of boron-modified Ti-15Al-33Nb (at.%)

C. J. Cowen, C. J. Boehlert

Research output: Research - peer-reviewArticle

  • 2 Citations

Abstract

The effect of boron on the microstructure, tensile, and creep behavior of a Ti-15Al-33Nb (at. pct) alloy was investigated. In addition to the normal constituent phases present in the unmodified alloy, the boron-modified alloys contained borides enriched in titanium and niobium. These borides made up to 9 pct of the volume and were present in the form of needles/laths. Boron additions of 5 at. pct resulted in significant strengthening and stiffening and reduced elongation-to-failure. Smaller boron additions of 0.5 at. pct did not as significantly impact the RT tensile properties, but reduced the 650 °C yield strength by 45 pct. Constant load, tensile-creep experiments were performed in the stress range of 150 to 400 MPa and the temperature range of 650 °C to 710 °C, in both air and vacuum environments. The addition of 5 at. pct boron significantly improved the creep resistance, whereas the addition of 0.5 at. pct boron degraded the creep resistance. In-situ tensile-creep experiments indicated that localized grain boundary cracking was prevalent at the prior-β grain boundaries.

LanguageEnglish (US)
Pages279-293
Number of pages15
JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume39
Issue number2
DOIs
StatePublished - Feb 2008
Externally publishedYes

Profile

Boron
Creep
Microstructure
boron
microstructure
Boron Compounds
Creep resistance
Grain boundaries
Experiments
Borides
tensile creep
creep strength
borides
grain boundaries
Niobium
Titanium
Tensile properties
Needles
Yield stress
Elongation

ASJC Scopus subject areas

  • Materials Science(all)
  • Metals and Alloys

Cite this

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abstract = "The effect of boron on the microstructure, tensile, and creep behavior of a Ti-15Al-33Nb (at. pct) alloy was investigated. In addition to the normal constituent phases present in the unmodified alloy, the boron-modified alloys contained borides enriched in titanium and niobium. These borides made up to 9 pct of the volume and were present in the form of needles/laths. Boron additions of 5 at. pct resulted in significant strengthening and stiffening and reduced elongation-to-failure. Smaller boron additions of 0.5 at. pct did not as significantly impact the RT tensile properties, but reduced the 650 °C yield strength by 45 pct. Constant load, tensile-creep experiments were performed in the stress range of 150 to 400 MPa and the temperature range of 650 °C to 710 °C, in both air and vacuum environments. The addition of 5 at. pct boron significantly improved the creep resistance, whereas the addition of 0.5 at. pct boron degraded the creep resistance. In-situ tensile-creep experiments indicated that localized grain boundary cracking was prevalent at the prior-β grain boundaries.",
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N2 - The effect of boron on the microstructure, tensile, and creep behavior of a Ti-15Al-33Nb (at. pct) alloy was investigated. In addition to the normal constituent phases present in the unmodified alloy, the boron-modified alloys contained borides enriched in titanium and niobium. These borides made up to 9 pct of the volume and were present in the form of needles/laths. Boron additions of 5 at. pct resulted in significant strengthening and stiffening and reduced elongation-to-failure. Smaller boron additions of 0.5 at. pct did not as significantly impact the RT tensile properties, but reduced the 650 °C yield strength by 45 pct. Constant load, tensile-creep experiments were performed in the stress range of 150 to 400 MPa and the temperature range of 650 °C to 710 °C, in both air and vacuum environments. The addition of 5 at. pct boron significantly improved the creep resistance, whereas the addition of 0.5 at. pct boron degraded the creep resistance. In-situ tensile-creep experiments indicated that localized grain boundary cracking was prevalent at the prior-β grain boundaries.

AB - The effect of boron on the microstructure, tensile, and creep behavior of a Ti-15Al-33Nb (at. pct) alloy was investigated. In addition to the normal constituent phases present in the unmodified alloy, the boron-modified alloys contained borides enriched in titanium and niobium. These borides made up to 9 pct of the volume and were present in the form of needles/laths. Boron additions of 5 at. pct resulted in significant strengthening and stiffening and reduced elongation-to-failure. Smaller boron additions of 0.5 at. pct did not as significantly impact the RT tensile properties, but reduced the 650 °C yield strength by 45 pct. Constant load, tensile-creep experiments were performed in the stress range of 150 to 400 MPa and the temperature range of 650 °C to 710 °C, in both air and vacuum environments. The addition of 5 at. pct boron significantly improved the creep resistance, whereas the addition of 0.5 at. pct boron degraded the creep resistance. In-situ tensile-creep experiments indicated that localized grain boundary cracking was prevalent at the prior-β grain boundaries.

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