A novel route to superhard nanocrystalline cubic boron nitride: Emulsion detonation and high-pressure high-temperature transformation-assisted consolidation. Issue 11 (September 2021)

• Record Type: Journal Article
• Authors: Petrusha, Igor; Hwang, Chawon; Prikhna, Tatiana; Örnek, Metin; Zhao, Dexin; Xie, Kelvin Y.; Haber, Richard A.; Karpets, Myroslav; Ponomaryov, Semyon; Dub, Sergey; Moshchil, Viktoer
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 11(2021)
• Page Start: 5505
• Page End: 5511
• Publication Date: 2021-09
• Subjects: Cubic boron nitride -- Nanocrystalline -- Emulsion detonation -- Superhard -- Transformation-assisted consolidation; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.04.042
• Languages: English
• ISSNs: 0955-2219

Abstract

Highlights: A novel route is demonstrated to synthesize superhard bulk nanocrystalline cubic boron nitride. A route that combines emulsion detonation and high pressure high temperature transformation-assisted consolidation. Design insights on how to refine grains while enhancing densification to synthesize bulk nanocrystalline materials. Abstract: Synthesizing bulk nanocrystalline materials is challenging since grain growth should be suppressed whereas densification promoted. Here, we demonstrate a novel route to synthesize superhard bulk nanocrystalline cubic boron nitride (cBN), which combines the use of emulsion detonation and high-pressure high-temperature transformation-assisted consolidation. The emulsion detonation process activates BN to possess unique structure and chemistry, i.e. wurtzitic BN nanograins in hexagonal BN matrix with enhanced structural disordering and oxygen impurity, a combination that enhances the nucleation rate of cBN and its densification leading to the formation of bulk nanocrystalline cBN at reduced conditions. The cBN, synthesized at 7.5 GPa and 1800 °C, displayed Vickers hardness values of 50−62 GPa for 5−20 N loads. The findings in the study suggest a feasible solution to synthesize bulk nanocrystalline cBN in a more scalable way, while also providing design insights on how to refine grain growth while enhancing densification to synthesize bulk nanocrystalline materials.