skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evolution of the mechanical properties of a cobalt-based alloy under thermal shocks

Abstract

A cobalt-base alloy manufactured by hot isostatic pressing sintering (HIP) was investigated in the present work. A series of quenching thermal-shock experiments were carried out to study the effects of thermal-cycle shocks on this new cobalt-based alloy. Scanning Electron Microscope (SEM) and Energy Dispersion Spectrum (EDS) were employed to observe the evolution of microstructures under thermal-shock cycles. Results show that some floccus Co3W3C precipitated around the WC particles after several thermal-shock cycles. These precipitates and the carbide particles correspond to the locations with the high-stress concentration. The mechanical properties evolution under thermal-shock cycles was analyzed by Nanoindentation tests. The nanohardness presents no noticeable change with thermal-shock cycles. However, the reduced modulus demonstrates a decreasing trend with the thermal-shock cycles. The variation of the mechanical properties has an unestimated relationship with the residual stress and densities of dislocations caused by thermal shocks. Furthermore, the present work pointed out that the precipitates around the carbides are the places where the thermal fatigue crack initiated. How to deal with the precipitates will be the optimized way for this material.

Authors:
 [1];  [2]; ORCiD logo [3];  [2];  [4];  [3]; ORCiD logo [4];  [4]; ORCiD logo [4]
  1. Lanzhou Univ. of Technology (China); Univ. of Tennessee, Knoxville, TN (United States); Liuzhou Vocational &Technical College (China)
  2. China Iron & Steel Research Inst. Group, Beijing (China)
  3. Lanzhou Univ. of Technology (China)
  4. Univ. of Tennessee, Knoxville, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE; National Science Foundation (NSF); National Natural Science Foundation of China (NSFC)
OSTI Identifier:
1606721
Grant/Contract Number:  
AC05-00OR22725; DMR-1611180; 1809640; 51761027; 51675255
Resource Type:
Accepted Manuscript
Journal Name:
Materials & Design
Additional Journal Information:
Journal Volume: 188; Journal Issue: C; Journal ID: ISSN 0264-1275
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; cobalt-based alloy; thermal shocks; nanoindentation test

Citation Formats

Wen, Junxia, Che, Hongyan, Cao, Rui, Dong, Hao, Ye, Youxiong, Zhang, Haiyan, Brechtl, Jamieson, Gao, Yanfei, and Liaw, Peter K. Evolution of the mechanical properties of a cobalt-based alloy under thermal shocks. United States: N. p., 2019. Web. https://doi.org/10.1016/j.matdes.2019.108425.
Wen, Junxia, Che, Hongyan, Cao, Rui, Dong, Hao, Ye, Youxiong, Zhang, Haiyan, Brechtl, Jamieson, Gao, Yanfei, & Liaw, Peter K. Evolution of the mechanical properties of a cobalt-based alloy under thermal shocks. United States. https://doi.org/10.1016/j.matdes.2019.108425
Wen, Junxia, Che, Hongyan, Cao, Rui, Dong, Hao, Ye, Youxiong, Zhang, Haiyan, Brechtl, Jamieson, Gao, Yanfei, and Liaw, Peter K. Fri . "Evolution of the mechanical properties of a cobalt-based alloy under thermal shocks". United States. https://doi.org/10.1016/j.matdes.2019.108425. https://www.osti.gov/servlets/purl/1606721.
@article{osti_1606721,
title = {Evolution of the mechanical properties of a cobalt-based alloy under thermal shocks},
author = {Wen, Junxia and Che, Hongyan and Cao, Rui and Dong, Hao and Ye, Youxiong and Zhang, Haiyan and Brechtl, Jamieson and Gao, Yanfei and Liaw, Peter K.},
abstractNote = {A cobalt-base alloy manufactured by hot isostatic pressing sintering (HIP) was investigated in the present work. A series of quenching thermal-shock experiments were carried out to study the effects of thermal-cycle shocks on this new cobalt-based alloy. Scanning Electron Microscope (SEM) and Energy Dispersion Spectrum (EDS) were employed to observe the evolution of microstructures under thermal-shock cycles. Results show that some floccus Co3W3C precipitated around the WC particles after several thermal-shock cycles. These precipitates and the carbide particles correspond to the locations with the high-stress concentration. The mechanical properties evolution under thermal-shock cycles was analyzed by Nanoindentation tests. The nanohardness presents no noticeable change with thermal-shock cycles. However, the reduced modulus demonstrates a decreasing trend with the thermal-shock cycles. The variation of the mechanical properties has an unestimated relationship with the residual stress and densities of dislocations caused by thermal shocks. Furthermore, the present work pointed out that the precipitates around the carbides are the places where the thermal fatigue crack initiated. How to deal with the precipitates will be the optimized way for this material.},
doi = {10.1016/j.matdes.2019.108425},
journal = {Materials & Design},
number = C,
volume = 188,
place = {United States},
year = {2019},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share: