Effect of Boron Concentration on Martensitic Transformation Temperatures, Stress for Inducing Martensite and Slip Stress of Ti-24 mol%Nb-3 mol%Al Superelastic Alloy

• Horiuchi Yosuke

  Precision and Intelligence Laboratory, Tokyo Institute of Technology

• Inamura Tomonari

  Precision and Intelligence Laboratory, Tokyo Institute of Technology

• Kim Hee Young

  Institute of Materials Science, University of Tsukuba

• Wakashima Kenji

  Precision and Intelligence Laboratory, Tokyo Institute of Technology

• Miyazaki Shuichi

  Institute of Materials Science, University of Tsukuba

• Hosoda Hideki

  Precision and Intelligence Laboratory, Tokyo Institute of Technology

Bibliographic Information

Other Title

• Effect of Boron Concentration on Martensitic Transformation Temperatures Stress for Inducing Martensite and Slip Stress of Ti 24モルパーセントNb 3モルパーセントAl Superelastic Alloy

Abstract

Effects of boron (B) addition on martensitic transformation temperature, stress for inducing martensite and slip stress of a Ti-24 mol%Nb-3 mol%Al (TiNbAl) superelastic alloy were investigated in a composition range from 0 to 0.10 mass%B. It was found that a second phase is formed by the B addition being higher than 0.05 mass%B. This second phase was estimated to be TiB. The averaged grain size of TiNbAl was decreased by the B addition being higher than 0.05 mass%B. This decrease must be explained by the suppression of grain growth by the second phase. The second phase plays a role of pining sites of grain boundary movement during the solution treatment. The martensitic transformation temperatures (M_s) measured by differential scanning calorimetry were decreased by the B addition. Superelastic behavior was evaluated by a cyclic loading-unloading tensile test at room temperature with a constant strain increment of 1%, and it was found that superelasticity appeared regardless of the amount of B addition. It was also found that stress for inducing martensitic transformation (σ_SIM) increased with increasing B concentration up to 0.05 mass%B. This increase of σ_SIM by the B addition can be explained by the lowering of M_s by the B addition. The critical stress for slip (σ_SLIP) increased with increasing the B concentration being up to 0.05 mass%B. The increase of σ_SLIP by B addition was evaluated to be 3 GPa/mass%B, and it was significantly higher than that of σ_SIM (500 MPa/mass%B) when the B concentration was less than 0.05 mass%B. These results indicate that B addition is effective to reduce the permanent unrecoverable strain introduced during deformation.

Journal

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 48 (3), 407-413, 2007

  The Japan Institute of Metals and Materials

Keywords

• TiNbAl
• boron addition
• superelasticity
• martensitic transformation
• stress for inducing martensite
• slip stress

Details

• CRID: 1390001204251317120
• NII Article ID: 130004453479
• NII Article ID: 10018734641
• NII Book ID: AA1151294X
• DOI: 10.2320/matertrans.48.407
• ISSN: 13475320
• ISSN: 13459678
• NDL BIB ID: 8670912
• Web Site: http://id.ndl.go.jp/bib/8670912
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8670912
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/48/3/48_MH200628/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed