Microstructural evolution during high-temperature tensile creep at 1,500°C of a MoSiBTiC alloy
Microstructural evolution in the TiC-reinforced Mo–Si–B-based alloy during tensile creep deformation at 1,500°C and 137 MPa was investigated via scanning electron microscope-backscattered electron diffraction (SEM-EBSD) observations. The creep curve of th...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
De Gruyter
2020-04-01
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Series: | High Temperature Materials and Processes |
Subjects: | |
Online Access: | https://doi.org/10.1515/htmp-2020-0039 |
Summary: | Microstructural evolution in the TiC-reinforced Mo–Si–B-based alloy
during tensile creep deformation at 1,500°C and 137 MPa was
investigated via scanning electron microscope-backscattered electron diffraction
(SEM-EBSD) observations. The creep curve of this alloy displayed no clear steady
state but was dominated by the tertiary creep regime. The grain size of the
Moss phase increased in the primary creep regime. However, the grain
size of the Moss phase was found to remarkably decrease to
<10 µm with increasing creep strain in the tertiary creep
regime. The EBSD observations revealed that the refinement of the Moss
phase occurred by continuous dynamic recrystallization including the transformation
of low-angle grain boundaries to high-angle grain boundaries. Accordingly, the
deformation of this alloy is most likely to be governed by the grain boundary sliding
and the rearrangement of Moss grains such as superplasticity in the
tertiary creep regime. In addition, the refinement of the Moss grains
surrounding large plate-like T2 grains caused the rotation of their
surfaces parallel to the loading axis and consequently the cavitation preferentially
occurred at the interphases between the end of the rotated T2 grains and
the Moss grains. |
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ISSN: | 0334-6455 2191-0324 |