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, cilt.33, ss.2729-2736, 2002 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 33 Konu: 8
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1007/s11661-002-0395-8
  • Dergi Adı: METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
  • Sayfa Sayıları: ss.2729-2736

Özet

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.