Suppressing η-phase development in steel-cemented tungsten carbide: A spark plasma sintering study
- Univ. of California, San Diego, CA (United States). Dept. of Mechanical and Aerospace Engineering; Alfred Univ., NY (United States). Kazuo Inamori School of Engineering
- Univ. of California, San Diego, CA (United States). Dept. of Mechanical and Aerospace Engineering
- Advanced Materials and Devices, Inc., Reno, NV (United States)
We describe the phase stability of a cemented tungsten carbide prepared using a high-vanadium tool steel as the cementing/binder phase and confirm suppression of (Fe, W)6C η-phase formation, attributed to the preferential formation of a V0.78W0.22C1-x phase that exists as islands within the Fe-rich binder matrix. The samples were prepared using spark plasma sintering (SPS), starting from commercially available WC and A11-LVC tool steel powders. The starting powders were ball milled adding 10, 15, and 20 vol.% steel. An A11-LVC tool steel was chosen as a low-cost hard steel (49 HRC) that does not contain Ni or Co but has a high vanadium (~9 wt.%) and carbon (~1.75 wt.%) content. Our results show that sintering by SPS can produce high-density (>98%) WC-steel specimens in which the matrix wets the WC grain surfaces and formation of the brittle η-phase is avoided. The η phase is often regarded as embrittling and undesirable, and its presence can result in degradation of mechanical properties. Microhardness values for the WC-10 and WC-15 vol.% steel samples were 12.3 ± 1.2 and 13.0 ± 0.9 GPa, respectively, whereas the fracture toughness values were 8.83 ± 0.48 and 8.81 ± 0.61 MPa·m1/2, respectively.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1488769
- Report Number(s):
- LLNL-JRNL-751653; 937352
- Journal Information:
- Journal of the American Ceramic Society, Vol. 102, Issue 2; ISSN 0002-7820
- Publisher:
- American Ceramic SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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