0
Research Papers

Effects of Silicon Content on the Microstructure and Mechanical Properties of Cobalt-Based Tribaloy Alloys

[+] Author and Article Information
Rong Liu

Department of Mechanical and
Aerospace Engineering,
Carleton University,
1125 Colonel By Drive,
Ottawa, ON K1S 5B6, Canada;
Research Center of Laser Processing
Technology and Engineering,
Zhejiang University of Technology,
Hangzhou, Zhejiang 310014, China
e-mail: Rong.Liu@carleton.ca

Jianhua Yao, Qunli Zhang

Research Center of Laser Processing
Technology and Engineering,
Zhejiang University of Technology,
Hangzhou, Zhejiang 310014, China

Matthew X. Yao, Rachel Collier

Kennametal Stellite, Inc.,
471 Dundas Street East,
Belleville, ON K8N 5C4, Canada

1Corresponding author.

Contributed by the Materials Division of ASME for publication in the JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY. Manuscript received July 31, 2015; final manuscript received June 9, 2016; published online August 8, 2016. Assoc. Editor: Marwan K. Khraisheh.

J. Eng. Mater. Technol 138(4), 041017 (Aug 08, 2016) (7 pages) Paper No: MATS-15-1176; doi: 10.1115/1.4034075 History: Received July 31, 2015; Revised June 09, 2016

Cobalt-based Tribaloy alloys are strengthened mainly by a hard, intermetallic Laves phase consisting of Co3Mo2Si or/and CoMoSi; therefore, silicon content plays a large role in the microstructure and performance of these materials. In this research, the microstructures of two cobalt-based Tribaloy alloys that are largely different in Si content are studied using scanning electron microscopy (SEM) with an EDAX energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD), fatigue strength under rotating-bending test, mechanical behavior under nanoindentation, and hardness at room and elevated temperatures using a microindentation tester. It is revealed that with higher silicon content (2.6 wt. %), T-400 has a hypereutectic microstructure with Laves phase as primary phase, whereas with lower silicon content (1.2 wt. %), T-401 has a hypoeutectic microstructure with solid solution as primary phase. T-400, containing lager volume fraction of Laves phase, exhibits better fatigue strength, in particular, at high stresses, while T-401, with less volume fraction of Laves phase, has improved ductility, exhibiting better resistance to fatigue at low stresses. The hardness of both alloys decreases with temperature, and T-401 shows higher reduction rate. T-400 is harder than T-401.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

SEM microstructures: (a) T-400 and (b) T-401

Grahic Jump Location
Fig. 2

EDX spectra of T-400: (a) phase in light and (b) phase in dark

Grahic Jump Location
Fig. 3

EDX spectra of T-401: (a) phase in dark and (b) phase in light

Grahic Jump Location
Fig. 4

XRD patterns of T-400 and T-401

Grahic Jump Location
Fig. 5

Stress–life (S–N) curves of T-400 and T-401 under rotating-bending test

Grahic Jump Location
Fig. 6

SEM morphologies of fatigue fractured surfaces under 400 MPa in rotating-bending test: (a) T-400 and (b) T-401

Grahic Jump Location
Fig. 7

Loading/unloading curves of indentation: (a) Laves phase and (b) solid solution

Grahic Jump Location
Fig. 8

Microscopic images of indentation on T-400: (a) Laves phase and (b) solid solution

Grahic Jump Location
Fig. 9

Microscopic images of indentation on T-401: (a) Laves phase and (b) solid solution

Grahic Jump Location
Fig. 10

Microhardness versus temperature of T-400 and T-401: (a) solid solution and (b) Laves phase

Grahic Jump Location
Fig. 11

Schematic pseudobinary section for Co–Mo–Cr–Si Tribaloy alloy system [19]

Grahic Jump Location
Fig. 12

SEM microstructure of T-401 at high magnification

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In