Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/43876
Title: Microstructural characterization, formation mechanism and fracture behavior of the needle δ phase in Fe-Ni-Cr type superalloys with high Nb content
Authors: Ning, Y
Huang, S
Fu, MW 
Dong, J
Keywords: Fe-Ni-Cr superalloys
Fractography
Hot working behavior
Mechanical property
Microstructural mechanism
Needle δ phase
Issue Date: 2015
Publisher: Elsevier
Source: Materials characterization, 2015, v. 109, p. 36-42 How to cite?
Journal: Materials characterization 
Abstract: Microstructural characterization, formation mechanism and fracture behavior of the needle δ phase in Fe-Ni-Cr type superalloys with high Nb content (GH4169, equivalent to Inconel 718) have been quantitatively investigated in this research. The typical microstructures of δ phases with the stick, mixed and needle shapes obviously present in Inconel 718 after the isothermal upsetting at the temperature of 980-1060 °C with the initial strain rate of 10- 3-10- 1 s- 1. It is found that the shape of the δ phase has a great effect on the mechanical properties of the alloy, viz., the stick δ phase behaves good plasticity and the needle δ phase has good strength. In addition, the needle δ phase can be used to control the grain size as it can prevent grain growth. The combined effect of the localized necking and microvoid coalescence leads to the final ductile fracture of the GH4169 components with the needle δ phase. Both dislocation motion and atom diffusion are the root-cause for the needle δ phase to be firstly separated at grain boundary and then at sub-boundary. The formation mechanism of the needle δ phase is the new finding in this research. Furthermore, it is the primary mechanism for controlling the needle δ phase in Fe-Ni-Cr type superalloys with high Nb content.
URI: http://hdl.handle.net/10397/43876
ISSN: 1044-5803
DOI: 10.1016/j.matchar.2015.09.011
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

4
Last Week
0
Last month
Citations as of Jun 22, 2017

WEB OF SCIENCETM
Citations

4
Last Week
0
Last month
Citations as of Jun 23, 2017

Page view(s)

17
Last Week
2
Last month
Checked on Jun 18, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.