Abstract
Calcium-stabilized alpha-sialon ceramics reinforced with cubic boron nitride (cBN) particles were synthesized using spark plasma sintering. The effects of the size of alpha-sialon precursor particle and the influence of the amount of cBN reinforcement on the physical, structural and mechanical characteristics of the composites were studied. Synthesis of the composites at 1500 °C with a holding time of 30 min resulted in densified composites. CBN-reinforced alpha-sialon composites synthesized via probe sonication showed particle sizes between 200 nm and 450 nm and showed significantly better mechanical properties than did the unreinforced sialon. A Vickers hardness (HV10) value of as high as 24.0 GPa was measured for this reinforced sialon, as compared to a value of 21.6 GPa for the pure alpha sialon. However, a phase transformation from alpha to beta sialon was observed when using high energy ball milling process condition, where the size of the alpha-forming precursors was decreased to about 100 nm. This phase transformation was accompanied by a simultaneous cubic-to-hexagonal boron nitride phase transformation.
| Original language | English |
|---|---|
| Pages (from-to) | 836-843 |
| Number of pages | 8 |
| Journal | Journal of Alloys and Compounds |
| Volume | 728 |
| DOIs | |
| State | Published - 2017 |
Bibliographical note
Funding Information:The authors would like to acknowledge the support provided by King Abdulaziz City for Science and Technology (KACST) through Science & Technology Unit at King Fahd University of Petroleum & Minerals ( KFUPM ) for funding this work through project No. 13-NAN1700-04 as part of National Science, Technology and Innovation Plan.
Publisher Copyright:
© 2017
Keywords
- Ceramics
- Composite materials
- High-energy ball milling
- Phase transformation
- Sialon
- Spark plasma sintering
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry