Suzuki segregation in Co-Ni-based superalloy at 973 K: An experimental and computational study by phase-field simulation

被引：93

作者：

Koizumi, Yuichiro ^{[1
]}

Nukaya, Takeshi ^{[1
]}

Suzuki, Sho ^{[1
]}

Kurosu, Shingo ^{[1
]}

Li, Yunping ^{[1
]}

Matsumoto, Hiroaki ^{[1
]}

Sato, Kazuhisa ^{[1
]}

Tanaka, Yuji ^{[1
]}

Chiba, Akihiko ^{[1
]}

机构：

[1] Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan

来源：

ACTA MATERIALIA | 2012年 / 60卷 / 6-7期

关键词：

Strain-aging; Transmission electron microscopy (TEM); Refractory metals; Interface segregation; Phase field models; STACKING-FAULT ENERGY; SUBSEQUENT HEAT-TREATMENT; CR-MO ALLOY; CU-SI ALLOY; YOUNGS MODULUS; DEFORMATION; TEMPERATURE; MICROSTRUCTURE; SYSTEM; TRANSFORMATION;

D O I：

10.1016/j.actamat.2012.01.054

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Suzuki segregation in Co-Ni-based superalloys is of longstanding interest. In this study, the development of widely extended stacking fault (SF) ribbons was confirmed in a Co-Ni-based superalloy aged at 973 K after deformation at room temperature, which supports the decrease in stacking fault energy (SFE) due to Suzuki segregation. In addition, the plastic deformation behaviors of Co-Ni-based superalloys with various Nb contents up to 3 wt.% were investigated focusing on the effect of Nb addition on dynamic strain-aging by Suzuki segregation. The negative strain-rate dependence of flow stress due to dynamic strain-aging became more significant with increasing Nb content; however, attempts to detect segregating elements by scanning transmission electron microscopy and energy-dispersive spectroscopy analysis were not successful. A phase-field simulation of Suzuki segregation suggested strong Ni depletion with segregation of Cr and Mo atoms at the SF, and the SFE can become negative as a consequence of the segregation. This agrees with the experimentally observed formation of wide SFs by the aging at 973 K after cold deformation. It is also suggested that Nb atoms are strongly depleted at SFs, and a small amount of Nb addition dramatically enhances Cr segregation, resulting in further decreases in the SFE, which is probably responsible for the observed enhancement of dynamic strain-aging by Nb addition. In addition, the local structural changes, such as short-range ordering and/or an in-plane ordering, accompanying the segregation were discussed as possible additional mechanisms for strain-aging enhancement. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：2901 / 2915

页数：15

共 37 条

[1] MICROSCOPIC THEORY FOR ANTIPHASE BOUNDARY MOTION AND ITS APPLICATION TO ANTIPHASE DOMAIN COARSENING [J].

ALLEN, SM ;

CAHN, JW .

ACTA METALLURGICA, 1979, 27 (06) :1085-1095

[2] FREE ENERGY OF A NONUNIFORM SYSTEM .1. INTERFACIAL FREE ENERGY [J].

CAHN, JW ;

HILLIARD, JE .

JOURNAL OF CHEMICAL PHYSICS, 1958, 28 (02) :258-267

[3] Phase-field models for microstructure evolution [J].

Chen, LQ .

ANNUAL REVIEW OF MATERIALS RESEARCH, 2002, 32 :113-140

[4]

CHEN LQ, 2004, CONTINUUM SCALE SIMU, P37

[5] High work-hardening rate and deformation twinning of Co-Ni-based superalloy at elevated temperatures [J].

Chiba, A ;

Li, XG ;

Kim, MS .

PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, 1999, 79 (07) :1533-1554

[6] Pin-on-disk wear behavior in a like-on-like configuration in a biological environment of high carbon cast and low carbon forged Co-29Cr-6Mo alloys [J].

Chiba, Akihiko ;

Kumagai, Kazushige ;

Nomura, Naoyuki ;

Miyakawa, Satoru .

ACTA MATERIALIA, 2007, 55 (04) :1309-1318

[7] Microstructure and mechanical properties of biomedical Co-29Cr-Mo alloy wire fabricated by a modified melt-spinning process [J].

Chiba, Akihiko ;

Nomura, Naoyuki ;

Ono, Yoshiki .

ACTA MATERIALIA, 2007, 55 (06) :2119-2128

[8] COBALT-BASED SUPERALLOYS FOR APPLICATIONS IN GAS-TURBINES [J].

COUTSOURADIS, D ;

DAVIN, A ;

LAMBERIGTS, M .

MATERIALS SCIENCE AND ENGINEERING, 1987, 88 :11-19

[9] Computational study of atomic mobility for fcc phase of Co-Fe and Co-Ni binaries [J].

Cui, Y. -W. ;

Jiang, M. ;

Ohnuma, I. ;

Oikawa, K. ;

Kainuma, R. ;

Ishida, K. .

JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION, 2008, 29 (01) :2-10

[10] MEASUREMENTS OF STACKING-FAULT ENERGIES IN CO-NI AND CO-NI-CR ALLOYS [J].

DRAPIER, JM ;

COUTSOUR.D ;

HABRAKEN, L .

ACTA METALLURGICA, 1967, 15 (04) :673-&

← 1 2 3 4 →