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Indexed by:期刊论文

Date of Publication:2009-05-01

Journal:JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

Included Journals:SCIE、EI、ISTIC、Scopus

Volume:25

Issue:3

Page Number:379-382

ISSN No.:1005-0302

Key Words:Ni-based superalloy; High magnetic field; Magnetostrictive strain energy; Precipitation

Abstract:The shape change of the gamma' precipitates of cast Ni-based superalloy K52 after aging treatment under a high magnetic field was investigated. The results show that duplex gamma' precipitates are present in the gamma matrix after aging treatment with or without the magnetic field. One is the coarse particles with average size of 500 nm; the other is fine spherical gamma' precipitates with average of 100 nm in diameter. The application of a 10T magnetic field only results in the shape of the coarse gamma' particles changing from spherical to cuboidal when the alloys subjected to the same heat treatments. This shape change was mainly discussed based on the strain energy increase caused by the difference in magnetostriction between the gamma matrix and gamma' precipitates. The fine gamma' particles still keep spherical. Further TEM observations shows that a number of gamma particles in nano-scale precipitate in the coarse gamma' particles in the specimens treated without the magnetic field. In addition, it was found that the magnetic field caused the decrease of the hardness in the alloy, and the hardness was associated with the field direction.