0
RESEARCH PAPERS

Effects of CO2 Laser Surface Processing on Fracture Behavior of Silicon Nitride Ceramic

[+] Author and Article Information
Li Sun, Wenping Jiang

Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701

Ajay P. Malshe1

Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701apm2@engr.uark.edu

Philip H. McCluskey

Technology & Solutions Division, Caterpillar Inc., Peoria, IL 61629

1

Corresponding author.

J. Eng. Mater. Technol 128(3), 460-467 (Jan 23, 2006) (8 pages) doi:10.1115/1.2203104 History: Received August 02, 2005; Revised January 23, 2006

Surface defects generated by grinding deteriorate the flexural strength of the silicon nitride (Si3N4) ceramic. In this paper, CO2 laser surface processing was applied to eliminate the grinding-induced defects. SEM micrograph showed that the surface integrity of Si3N4 samples was improved after laser processing. Four-point bending tests and fractographic analysis indicated that the flexural strength and fracture origins were affected by the change of surface integrity in laser-treated Si3N4 samples. The effect of grinding-induced residual stress on flexural strength of laser-treated samples was discussed. It was concluded that laser surface processing had significant effects on fracture behavior of flexure Si3N4 samples.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Microstructure of the Si3N4 ceramic in this study

Grahic Jump Location
Figure 2

Experimental setup for CO2 laser surface processing of Si3N4 samples

Grahic Jump Location
Figure 3

Surface morphology of Si3N4 samples before and after laser treatments

Grahic Jump Location
Figure 4

The total area of cavities and fracture areas in an area of 4000μm2 on the surface of samples before and after laser treatments

Grahic Jump Location
Figure 5

Cross-sectional metallographs of Si3N4 samples: (a) untreated sample (SP: secondary phase); (b) laser treated with 70MW∕m2, 0.5mm∕s

Grahic Jump Location
Figure 6

Average flexural strength of Si3N4 samples before and after CO2 laser treatments

Grahic Jump Location
Figure 7

Weibull strength distribution plot of Si3N4 samples before and after CO2 laser treatments

Grahic Jump Location
Figure 8

SEM photos illustrating the fracture surface of an untreated sample (617MPa): (a) fracture surface, (b) fracture mirror, and (c) fracture origin

Grahic Jump Location
Figure 9

SEM photos showing the fracture surface of an untreated sample (583MPa): (a) fracture surface, (b) fracture mirror, and (c) fracture origin

Grahic Jump Location
Figure 10

SEM photos illustrating the fracture surface of a sample treated with condition 30MW∕m2‐0.1mm∕s(670MPa): (a) fracture surface, (b) fracture mirror, and (c) fracture origin

Grahic Jump Location
Figure 11

SEM photos showing the fracture surface of a sample treated with condition 70MW∕m2‐0.5mm∕s(721MPa): (a) fracture surface, (b) fracture mirror, and (c) fracture origin

Grahic Jump Location
Figure 12

Correlation between the fracture origins and laser processing conditions

Grahic Jump Location
Figure 13

Residual stress of ground Si3N4 samples before and after CO2 laser treatments

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