| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
|
| Presentation Title |
Towards Superhard Binderless Nanocrystalline Tungsten Carbide |
| Author(s) |
Kevin P. Anderson, James A. Wollmershauser, Heonjune Ryou, Edward P. Gorzkowski, Boris N. Feigelson |
| On-Site Speaker (Planned) |
Kevin P. Anderson |
| Abstract Scope |
Tungsten carbide, with a typical Vickers hardness ~26 GPa, is not generally considered a superhard material (Hv > 40 GPa). In this work, fully dense, binderless nanocrystalline tungsten carbide ceramics with a Vickers hardness as high as 39 GPa and indentation fracture resistance values of > 9 MPa√m were produced by Environmentally Controlled – Pressure Assisted Sintering (EC-PAS). EC-PAS utilizes applied pressure (2 GPa), low temperature (< 0.5 Tm), and creation and preservation of pristine nanoparticle surfaces throughout the sintering process to achieve densification with negligible grain growth. Tungsten carbide ceramics produced through this process had grain sizes as small as 26 nm and were characterized with XRD, SEM (including XEDS and EBSD), Vickers microindentation, and instrumented nanoindentation. The mechanical properties – microstructure relationship will be discussed with respect to the powder processing and sintering conditions, in addition to possible process improvements leading to further increases in hardness. |