Composite formed of cubic boron nitride and method of making thereof
A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 15-45 vol. % titanium (Ti)-containing binders, about 2-20 vol. % zirconium dioxide (ZrO 2 ), about 3-15 vol. % cobalt-tungsten-borides (Co x W y B z ), and about 2-15 vol. % aluminum oxide (Al 2 O 3 ).
1. A cubic boron nitride (cBN)-based composite, consisting of:
about 30-65 vol. % cBN;
about 15-45 vol. % titanium (Ti)-containing binders;
about 3-15 vol. % zirconium dioxide (ZrO 2 );
about 3-8 vol. % cobalt-tungsten-borides (Co x W y B z );
about 2-15 vol. % aluminum oxide (Al 2 O 3 ); and
less than or equal to about 10 vol. % titanium diboride (TiB 2 ).
2. The cBN-based composite of claim 1 , wherein the Co x W y B z is selected from the group consisting of crystalline CoWB, crystalline CoW 2 B 2 , and crystalline W 3 CoB 3 .
3. The cBN-based composite of claim 1 , wherein the W and Co are present in a W/Co weight ratio of about 3 to about 8.
4. The cBN-based composite of claim 1 , wherein the cBN has a grain size of about 0.1 micrometer (μm)-4 μm.
5. The cBN-based composite of claim 1 , wherein the cBN has a grain size of about 0.1 micrometer (μm)-2 μm.
6. The cBN-based composite of claim 1 , wherein the cBN has a grain size of about 0.1 micrometer (μm)-1 μm.
7. A cutting tool for cutting superalloys, comprising the cBN-based composite of claim 1 .
8. A method of forming a cubic boron nitride (cBN)-based composite, comprising:
mixing powders of a cBN-based formulation for forming the cBN-based composite to form a first mixture, the cBN-based composite consisting of
about 30-65 vol. % cBN,
about 15-45 vol. % titanium (Ti)-containing binders,
about 3-15 vol. % zirconium dioxide (ZrO 2 ),
about 3-8 vol. % cobalt-tungsten-borides (Co x W y B z ),
about 2-15 vol. % aluminum oxide (Al 2 O 3 ), and
less than or equal to about 10 vol. % titanium diboride (TiB 2 );
drying the first mixture to form a second mixture;
loading the second mixture into one or more refractory molds; and
sintering the second mixture at high-pressure-high-temperature conditions.
9. The method of claim 8 , further comprising mixing the powders of the cBN-based formulation with one or more solvents comprising ethanol, isopropanol, acetone, methanol, hexane, heptane, or a combination thereof to form the first mixture.
10. The method of claim 8 , wherein drying the first mixture comprises vacuum drying the first mixture.
11. The method of claim 8 , wherein loading the second mixture comprises disposing the second mixture and a cemented carbide (WC—Co) substrate or disc in the one or more refractory molds.
12. The method of claim 8 , further comprising sintering the second mixture at a pressure of at least 4 gigapascal (GPa) and at a temperature of at least 1100° C.
13. A cutting tool, comprising:
a sintered cubic boron nitride (cBN)-based compact consisting of
about 30-65 vol. % cBN;
about 15-45 vol. % titanium (Ti)-containing binders;
about 3-15 vol. % zirconium dioxide (ZrO 2 );
about 3-8 vol. % cobalt-tungsten-borides (Co x W y B z );
about 2-15 vol. % aluminum oxide (Al 2 O 3 ); and
less than or equal to about 10 vol. % titanium diboride (TiB 2 ).
14. The cutting tool of claim 13 , wherein the Co x W y B z is selected from the group consisting of crystalline CoWB, crystalline CoW 2 B 2 , and crystalline W 3 CoB 3 .
15. The cutting tool of claim 13 , wherein the W and Co are present in a W/Co weight ratio of about 3 to about 8.