Methods of forming abrasive articles

1. An abrasive article, comprising:

a polycrystalline material comprising abrasive grains separated by grain boundaries, wherein the grain boundaries comprise a filler material having an average negative coefficient of thermal expansion (CTE) within a range of temperatures between about 70 K to about 1500 K, wherein the filler comprises at least one material selected from the group consisting of a tungstate, a molybdate, and a vanadate.

2. An abrasive article, comprising:

a substrate having an upper surface; and

an abrasive layer overlying the upper surface of the substrate, wherein the abrasive layer comprises abrasive grains and a filler material, wherein the filler material has an average coefficient of thermal expansion (CTE) of not greater than zero within a range of temperatures between about 70 K and about 1500 K, and wherein the filler material comprises an isopolyoxometalate.

3. The abrasive article of claim 2 , wherein the filler material has an average negative coefficient of thermal expansion (CTE) within a range of temperatures between about 70 K to about 1500 K.

4. The abrasive article of claim 2 , wherein the filler material comprises a material in a polycrystalline phase.

5. The abrasive article of claim 2 , wherein the abrasive grains exhibit an average grain size from about 0.1 μm to about 40 μm.

6. The abrasive article of claim 1 , further comprising a passivation agent dispersed throughout the polycrystalline material.

7. The abrasive article of claim 6 , wherein the passivation agent exhibits a CTE of not greater than about 20×10 −6 /K within a range of temperatures between about 70 K to about 1500 K.

8. The abrasive article of claim 7 , wherein the passivation agent exhibits a CTE from about 1×10 −6 /K to about 15×10 −6 /K within a range of temperatures between about 70 K to about 1500 K.

9. The abrasive article of claim 6 , wherein the passivation agent comprises at least one material selected from the group consisting of metals, metal alloys, ceramics, and cermets.

10. The abrasive article of claim 9 , wherein the passivation agent comprises at least one material selected from the group consisting of elements from Group III, Group IV, Group V, and Group VI of the Periodic Table of Elements.

11. The abrasive article of claim 10 , wherein the passivation agent comprises at least one material selected from the group consisting of Mn, V, Ti, Sc, Zr, Pd, Mo, Ta, W, Hf, Pt, La, Nd, and Nb.

12. The abrasive article of claim 6 , wherein the polycrystalline material comprises from about 1% to about 10% passivation agent by volume.

13. The abrasive article of claim 12 , wherein the polycrystalline material comprises from about 1% to about 5% passivation agent by volume.

14. The abrasive article of claim 2 , wherein the filler material comprises a material selected from the group of oxides consisting of AMO 3 , AM 2 O 8 , AM 2 O 7 , A 2 M 3 O 12 , and combinations thereof, wherein A represents a metal element, M represents a metal element different from the metal element represented by A, and O represents oxygen.

15. The abrasive article of claim 14 , wherein A represents at least one metal selected from the group consisting of Zr, Hf, Sn, U, Th, Sc, Al, Fe, and Cr.

16. The abrasive article of claim 14 , wherein M represents at least one metal selected from the group consisting of W, Mo, P, and V.

17. The abrasive article of claim 1 , wherein the filler material comprises zirconium tungstate.

18. The abrasive article of claim 1 , wherein the polycrystalline material comprises from about 1% to about 50% filler material by volume.

19. The abrasive article of claim 18 , wherein the polycrystalline material comprises from about 1% to about 10% filler material by volume.

20. The abrasive article of claim 1 , wherein the polycrystalline material further comprises a catalyst material exhibiting a CTE from about 0.1×10 −6 /K to about 15×10 −6 /K within a range of temperatures between about 70 K to about 1500 K.