Titanium Powders via Gas-Solid Direct Reaction Process and Mechanical Properties of Their Extruded Materials

• Mimoto Takanori

  Department of Mechanical Engineering, Graduate School of Engineering, Osaka University

• Umeda Junko

  Joining and Welding Research Institute, Osaka University

• Kondoh Katsuyoshi

  Joining and Welding Research Institute, Osaka University

Abstract

In the present study, titanium (Ti) powders containing some nitrogen (N) atoms were prepared by a gas (N₂)-solid (Ti starting powder) direct reaction process, and consolidated as an extruded rod with high strength and ductility at ambient temperature. Nitrogen content of the Ti powders via the gas-solid direct reaction process dramatically increased as the treatment time increased while no change in the oxygen content. Ti₂N layers were formed at Ti powder surfaces via the above gas-solid reaction, however, no formation of Ti₂N compounds was found in the extruded Ti materials. That is, the solid solution of N atoms in α-Ti was complete, and expected to enhance the mechanical strength of Ti materials. 0.2% yield strength (YS) and ultimate tensile strength (UTS) of wrought Ti-N materials were proportional to the additive nitrogen content, and the decrease of elongation was very limited. For example, the extruded Ti powder material with nitrogen content of 0.74 mass% revealed 974 MPa in 0.2%YS, 1120 MPa in UTS and 21.7% in elongation. These tensile properties were superior to those of the conventional Ti-6Al-4V alloy with the standard specification of ASTM B348-00-GR5 (0.2%YS: 918 MPa, UTS: 1047 MPa, elongation: 16.6%).

Journal

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 56 (8), 1153-1158, 2015

  The Japan Institute of Metals and Materials

Keywords

• titanium
• nitrogen
• solid solution hardening
• hot extrusion
• powder metallurgy

Details

• CRID: 1390282679229695616
• NII Article ID: 130005088955
• NII Book ID: AA1151294X
• DOI: 10.2320/matertrans.l-m2015816
• ISSN: 13475320
• ISSN: 13459678
• NDL BIB ID: 026623456
• Web Site: http://id.ndl.go.jp/bib/026623456
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I026623456
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/56/8/56_L-M2015816/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed