1. Microstructural and mechanical properties of cBN-Si composites prepared from the high pressure infiltration method.
- Author
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Liu, Yinjuan, He, Duanwei, Wang, Pei, Yan, Xiaozhi, Xu, Chao, Liu, Fangming, Liu, Jin, and Hu, Qiwei
- Subjects
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SCANNING electron microscopy , *ELECTRON microscopy , *INFILTRATION (Military science) , *POLYCRYSTALLINE semiconductors , *HEAT stability in proteins - Abstract
The grain size dependence of the mechanical properties of cBN-Si composites prepared using the high pressure infiltration method has been investigated. Indentation testing indicates that cBN-Si composites have hardness values of 38–43 GPa, which increase with increasing grain size and are harder than traditional polycrystalline cBN composites (PcBNs). Thermostability analyses display that cBN-Si composites with a grain size of > 9 μm also possess a higher temperature of oxidation, compared to traditional PcBNs, and the thermostability increases with increasing cBN grain size. Fracture toughness tests show that almost no cracks appear on the polished cBN-Si samples when the loading forces are increased to 294 N and the fracture toughness is better than for commercial samples. Scanning electron microscopy illustrates that deformations and close pores occurred easily between coarse BN grains, leading to denser cBN-Si compacts with better mechanical performances. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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