Chapter 24. Effect of Microstructure on Wear Behaviour of Silicon Nitride
- Mrityunjay Singh and
- Todd Jessen
Published Online: 26 MAR 2008
Copyright © 2001 The American Ceramic Society
25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3
How to Cite
Nakamura, M., Hirao, K., Sakaguchi, S., Yamauchi, Y. and Kanzaki, S. (2001) Effect of Microstructure on Wear Behaviour of Silicon Nitride, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294680.ch24
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2001
Print ISBN: 9780470375730
Online ISBN: 9780470294680
The mechanical and tribological properties of Si3N4 are dependent on its microstructure. In particular, grain morphology is a significant factor for controlling wear resistance. In this study, a silicon nitride ceramic with uni-directionally aligned ß-Si3N4 grains (UA-SN) was fabricated by an extruding method with a small amount of rodlike ß-Si3N4 seed. The effect of anisotropy in microstructure on tribological properties was investigated. Block-on Ring tests without lubricant were carried out at sliding speed of 1.5 m\s, normal load of 5 N and a sliding distance of 75 m, using commercially supplied Si3N4 as ring specimens. For evaluating tribological properties, wear tests were carried out in three different orientations relative to the grain alignment; the plane normal to the grain alignment (N), and in the directions both parallel (S-para) and perpendicular (S-perp) to the grain alignment in the plane of grain alignment. The N specimen exhibited the highest wear resistance, and the worn surface of this plane was quite smooth, in contrast to the other specimens whose surfaces were irregular owing to grain dropping. It is considered that the high wear resistance in this plane is attributable to the inhibition of crack propagation along the sliding surface by the stacked elongated ß-grains normal to the sliding surface.
In addition, α-Si3N4 ceramics with in-plane aligned ß-Si3N4 grains (IP-SN) were produced by tape casting. The relationship between ß content and tribological and mechanical properties was investigated. The results are discussed in comparison of the wear behaviour of UA-SN.