Decomposition of High Temperature γ<SUB>Mn</SUB> Phase during Continuous Cooling and Resultant Damping Behavior in Mn<SUB>74.8</SUB>Cu<SUB>19.2</SUB>Ni<SUB>4.0</SUB>Fe<SUB>2.0</SUB> and Mn<SUB>72.4</SUB>Cu<SUB>20.0</SUB>Ni<SUB>5.6</SUB>Fe<SUB>2.0</SUB> Alloys

• Yin Fuxing

  National Research Institute for Metals

• Ohsawa Yoshiaki

  National Research Institute for Metals

• Sato Akira

  National Research Institute for Metals

• Kawahara Kohji

  B. B. Materia Co. Ltd.

Bibliographic Information

Other Title

• Decomposition of High Temperature γMn Phase during Continuous Cooling and Resultant Damping Behavior in Mn74.8Cu19.2Ni4.0Fe2.0 and Mn72.4Cu20.0Ni5.6Fe2.0 Alloys
• Decomposition of High Temperature ガンマ M
• Decomposition of High Temperature &gamma;<SUB>Mn</SUB> Phase during Continuous Cooling and Resultant Damping Behavior in Mn<SUB>74.8</SUB>Cu<SUB>19.2</SUB>Ni<SUB>4.0</SUB>Fe<SUB>2.0</SUB> and Mn<SUB>72.4</SUB>Cu<SUB>20.0</SUB>Ni<SUB>5.6</SUB>Fe<SUB>2.0</SUB> Alloys

Abstract

The temperature dependent changes of logarithmic decrement δ and Young’s modulus E were measured for continuously cooled Mn_74.8Cu_19.2Ni_4.0Fe_2.0 and Mn_72.4Cu_20.0Ni_5.6Fe_2.0 (at%) alloys, after solid solution holding at 1173 K. Microstructure of those alloys, cooled to room temperature in different rates, was characterized by X-ray diffraction and electron microscopy. Ni apparently inhibited the decomposition of high temperature γ_Mn phase during cooling, so lower fcc-fct transformation temperatures (T_t) were observed in Mn_72.4Cu_20.0Ni_5.6Fe_2.0 alloy. Besides, several fct phases with different lattice parameters or T_t temperatures, i.e. an appearance of compositional heterogeneity in the Mn-enriched fraction, were also manifested in the alloy with Ni of 5.6 at%. Large amounts of (011) twinning plates were observed as a typical feature in the microstructure of Mn_74.8Cu_19.2Ni_4.0Fe_2.0 alloy. However, tetragonal distortion caused mis-fitting at the twinning boundaries resulted in a rapid reduction of logarithmic decrement in the vicinity of 273 K. Meanwhile, a larger amount of precipitated Cu-enriched phase confined the formation and growth of twinning plates in the fct phases, and hence reduced logarithmic decrements. In contrast, a tweed microstructure in Mn_72.4Cu_20.0Ni_5.6Fe_2.0 alloy sustained the high damping capacity in a wide temperature range near 273 K, irrespective of the cooling rates.

Journal

• Materials Transactions, JIM

  Materials Transactions, JIM 39 (8), 841-848, 1998

  The Japan Institute of Metals

Keywords

• logarithmic decrement
• Young’s modulus
• phase decomposition
• (011) twinning plate
• tweed microstructure

Details

• CRID: 1390282679223421568
• NII Article ID: 130003557068
• NII Article ID: 10003803499
• NII Book ID: AA10699969
• DOI: 10.2320/matertrans1989.39.841
• COI: 1:CAS:528:DyaK1cXms1Ont7k%3D
• ISSN: 2432471X
• ISSN: 09161821
• NDL BIB ID: 4549325
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4549325
• Web Site: https://www.jstage.jst.go.jp/article/matertrans1989/39/8/39_8_841/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed