Improvement in recrystallization temperature and mechanical properties of a commercial TZM alloy through microstructure control by multi-step internal nitriding

Masahiro Nagae, Tetsuo Yoshio, Jun Takada, Yutaka Hiraoka

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

In order to develop a molybdenum alloy with high recrystallization temperature and excellent mechanical properties, multi-step internal nitriding of a commercial TZM alloy (Titanium-Zirconium-Molybdenum alloy) was studied through optical and transmission electron microscopy, fractographic analysis and three-point bending tests. Two types of nitriding processes, a two-step and another four-step process, were carried out at temperatures between 1423 and 1873 K. Recrystallization was completely suppressed, even at the center of a 1-mm-thick specimen through four-step nitriding, whereas recrystallization proceeded at the specimen center in the case of two-step nitriding. The recrystallization temperature of the TZM alloy in vacuum was raised above 1973 K by four-step nitriding. The ductile-to-brittle transition temperature (DBTT) of the nitrided TZM alloy depended strongly on the thickness of the deformed microstructure. DBTT of the four-step nitriding specimen was below 130 K, which is about 70 K lower than that of the two-step nitriding specimen. The yield stress of the four-step nitriding specimen at 1773 K was about 2.6 times as large as that of the recrystallized specimen.

Original languageEnglish
Pages (from-to)2129-2134
Number of pages6
JournalMaterials Transactions
Volume46
Issue number10
DOIs
Publication statusPublished - Oct 2005

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nitriding
Nitriding
mechanical properties
Mechanical properties
microstructure
Microstructure
Molybdenum alloys
molybdenum alloys
Temperature
temperature
Superconducting transition temperature
transition temperature
Zirconium alloys
zirconium alloys
Bending tests
Titanium alloys
titanium alloys
Yield stress
Vacuum
Transmission electron microscopy

Keywords

  • Ductile-to-brittle transition temperature
  • Fractographic analysis
  • High-temperature strength
  • Multi-step internal nitriding
  • Recrystallization temperature
  • TZM alloy (Titanium-Zirconium-Molybdenum alloy)

ASJC Scopus subject areas

  • Materials Science(all)
  • Metals and Alloys

Cite this

Improvement in recrystallization temperature and mechanical properties of a commercial TZM alloy through microstructure control by multi-step internal nitriding. / Nagae, Masahiro; Yoshio, Tetsuo; Takada, Jun; Hiraoka, Yutaka.

In: Materials Transactions, Vol. 46, No. 10, 10.2005, p. 2129-2134.

Research output: Contribution to journalArticle

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