Boron nitride composites

1. A composite product, comprising:

hexagonal boron nitride (hBN);

a plurality of cubic boron nitride (cBN) particles, wherein the plurality of cBN particles are dispersed in a matrix of the hBN; and

one or more binders present in the composite product at about 2 to about 25 vol. %, wherein the one or more binders include one or more borates.

2. A composite product, comprising:

hexagonal boron nitride (hBN); and

a plurality of cubic boron nitride (cBN) particles,

wherein the plurality of cBN particles are dispersed in a matrix of the hBN,

wherein the cBN particles are present in an amount ranging from about 15 to about 90 vol. %,

wherein the cBN particles comprise a first average particle size and a second average particle size, wherein the second average particle size is at least one order of magnitude smaller than the first average particle size.

3. The composite product of claim 2 , further comprising one or more binders present in the composite product at about 2 to about 25 vol. %.

4. The composite product of claim 3 , wherein the one or more binders are selected from the group consisting of: calcium borate, potassium borate, magnesium borate, lithium tetraborate, and combinations thereof.

5. The composite product of claim 2 , wherein no binder material other than the hBN is present in the composite product.

6. The composite product of claim 2 , wherein an average particle size of the cBN particles is about 0.5 nm to about 250 microns.

7. The composite product of claim 2 , wherein each of the cBN particles is a single crystal of cBN.

8. The composite product of claim 2 , wherein an average particle size of the cBN particles is about 0.5 nm to about 15 microns.

9. The composite product of claim 2 , further comprising amorphous boron nitride.

10. The composite product of claim 3 , wherein a plurality of the binders are present in the composite product at about 2 to about 25 vol. %, wherein one or more of the plurality of binders are present in a crystalline phase and one or more of the plurality of binders are present in an amorphous phase.

11. The composite product of claim 2 , wherein a ratio of the volume percent of the cBN particles comprising the first average particle size to the cBN particles comprising the second average particle size is about 1:1 to about 10:1.

12. A composite product, comprising:

a plurality of cubic boron nitride (cBN) particles dispersed in a matrix,

wherein one or more of the cBN particles have a first average particle size and one or more of the cBN particles have a second average particle size that is smaller than the first average particle size.

13. The composite product of claim 12 , wherein the second average particle size is at least one order of magnitude smaller than the first average particle size.

14. The composite product of claim 12 , wherein a ratio of the volume percent of the one or more cBN particles having the first average particle size to the one or more cBN particles having the second average particle size is about 1:1 to about 10:1.

15. The composite product of claim 12 , wherein the matrix comprises a material selected from the group consisting of: hexagonal boron nitride (hBN), amorphous boron nitride, one or more borate binders, and combinations thereof.

16. The composite product of claim 15 , wherein the matrix comprises the one or more borate binders in an amount ranging from about 2 to about 25 vol. %.

17. The composite product of claim 16 , wherein the one or more borate binders are selected from the group consisting of: calcium borate, potassium borate, magnesium borate, lithium tetraborate, and combinations thereof.

18. The composite product of claim 12 , wherein the cBN particles are present in an amount ranging from about 15 to about 90 vol. %.