Solid Solution Hardening and Precipitation Hardening of α₂-Ti₃Al in Ti-Al-Nb Alloys

• Shimagami Kei

  Shibaura Institute of Technology National Institute of Materials Science

• Matsunaga Sae

  Purdue University

• Yumoto Atsushi

  Shibaura Institute of Technology

• Ito Tsutomu

  National Institute of Materials Science National Institute of Technology, Kagawa College

• Yamabe-Mitarai Yoko

  National Institute of Materials Science

書誌事項

タイトル別名

• Solid Solution Hardening and Precipitation Hardening of α₂-Ti₃Al in Ti-Al-Nb Alloys

抄録

Microstructure and mechanical properties of Ti-Al-Nb-based alloys were investigated as they are important in the development of new generation high temperature Ti alloys due to good oxidation resistance. The alloy compositions Ti-15Al-2Nb (to obtain α₂ precipitates) and Ti-15Al-2Nb-0.5Si (at%) (to obtain solid-solution hardening by Si) were selected. Heat treatment at 1000℃ after forging and rolling at 900℃ transformed the β phase to α phase and α' martensite during cooling. By heat treatment at 900℃, a single α phase was obtained in both alloys. The α₂ phase was formed by aging treatment at 600 and 700℃ of Ti-15Al-2Nb and at 600, 700, and 800℃ of Ti-15Al-2Nb-0.5Si. Compressive strength was investigated for samples heat treated at 900℃ with a single α phase and those aged at 600, 700, 800℃ with α₂ precipitates. The solid solution hardening effect of Si was found at all test temperatures. Precipitation hardening effect by α₂ precipitates was also observed in both alloys and the effect improved with Si addition. Peaks of precipitation hardening were obtained at 300℃ in both alloys; the precipitation hardening effect decreased with increase of test temperature above 300℃. It is suggested that a shearing mechanism occurs up to 300℃, which changes to a bypass mechanism above 450℃.

収録刊行物

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 58 (10), 1404-1410, 2017

  公益社団法人 日本金属学会

キーワード

• titanium alloy
• α phase
• α₂-Ti₃Al
• compressive strength
• solid solution hardening
• precipitation hardening

詳細情報

• CRID: 1390001204254421632
• NII論文ID: 130006096704
• NII書誌ID: AA1151294X
• DOI: 10.2320/matertrans.maw201707
• ISSN: 13475320
• ISSN: 13459678
• NDL書誌ID: 028534725
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I028534725
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/58/10/58_MAW201707/_pdf
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可