About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
|
Symposium
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Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
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Presentation Title |
Nanostructural Effects Beyond Hall-Petch: Towards Superhard Tungsten Carbide |
Author(s) |
Kevin P. Anderson, James Wollmershauser, Heonjune Ryou, Ramasis Goswami, Sarshad Rommel, Mark Aindow, Edward Gorzkowski, Boris Feigelson |
On-Site Speaker (Planned) |
Kevin P. Anderson |
Abstract Scope |
Industrial application of superhard materials (Vickers hardness, HV > 40 GPa) such as diamond and cubic boron nitride is limited by high costs and complex routes of synthesis. Tungsten carbide (WC) is a common industrial material valued for its hardness, but falls well short of qualification as a superhard material even in its less common but harder binderless form (HV ~ 26 GPa). However, despite recent advances in sintering technology, even the smallest grained binderless WC (<100 nm) has failed to achieve HV values above 33 GPa. In this work, multiple hardening mechanisms are exploited through a unique sintering approach proving WC as a candidate superhard material. Environmentally Controlled – Pressure Assisted Sintering (EC-PAS) is utilized to produce dense, binderless nanocrystalline WC ceramics with hardness as high as 39 GPa. The unprecedented WC hardness is attributed to the combined effects of small average crystallite size and deformation-induced nanoscale intragranular defects. |