Grain-size control in Ti-48Al-2Cr-2Nb with yttrium additions


Trivedi P., BABURAJ E., GENC A., Ovecoglu L. , PATANKAR S., FROES F.

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, vol.33, no.8, pp.2729-2736, 2002 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 33 Issue: 8
  • Publication Date: 2002
  • Doi Number: 10.1007/s11661-002-0395-8
  • Title of Journal : METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
  • Page Numbers: pp.2729-2736

Abstract

A gas-atomized (GA) prealloyed powder of the Ti-48Al-2Cr-2Nb intermetallic and 1.6 wt pct Y were mechanically alloyed (MA) and hot isostatically pressed (hipped) to produce a fully dense nanocrystalline material. Mechanical alloying of the as-blended powder for 16 hours resulted in the formation of a disordered fcc phase. Hipping of the alloy powder produced a single-phase nanocrystalline TiAl intermetallic, containing a distribution of 20 to 35-nm-sized Al2Y4O9 particles. The formation of oxide particles occurred by the chemical combination of Al and Y with oxygen, which entered as a contaminant during milling. Oxide particles increased the hardness of the intermetallic compound and minimized grain growth even at 0.8 T-m, where T-m is the melting point of the compound.