Composite refractory coatings and applications thereof
In one aspect, articles are described comprising wear resistant coatings employing one or more composite refractory layers. For example, a coated article described herein comprises a substrate and a coating deposited by CVD adhered to the substrate, the coating including a multiphase refractory layer comprising an alumina phase and a zirconia phase, wherein the zirconia phase has a texture coefficient for the (200) growth direction, TC(200), greater than 4.
1. A coated article comprising:
a substrate; and
a costing deposited by chemical vapor deposition (CVD) adhered to the substrate, the coating including a multiphase refractory layer comprising an alumina phase and zirconia phase, wherein the zirconia phase has a texture coefficient for the (200) growth direction, TC(200), greater than 4, the texture coefficient (TC) being defined as:
TC
(
hkl
)
=
I
(
hkl
)
I
o
(
hkl
)
{
1
n
∑
I
(
hkl
)
I
o
(
hkl
)
}
-
1
where
I(hkl)=measured intensity of the (hkl) reflection
I o (hkl)=standard intensity of the (hkl) reflection according to International Center for Diffraction Data (ICDD) card 00-037-1484
n=number of reflections used in the TC calculation
(hkl) reflections used in the TC calculation are (−111), (111), (200), (−112), (220) and (−221).
2. The coated article of claim 1 , wherein the TC(200) is greater than 45.
3. The coated article of claim 1 , wherein the TC(200) is greater than 5.
4. The coated article of claim 1 , wherein the TC(200) is greater than 5.5.
5. The coated article of claim 1 , wherein the TC(200) is from 4.1 to 6.
6. The coated article of claim 1 , wherein the alumina phase is doped with zirconium.
7. The coated article of claim 6 , wherein zirconium is present in the alumina phase in an amount of 0.1-3 weight percent of the alumina phase.
8. The coated article of claim 6 , wherein the alumina phase is α-alumina, κ-alumina or mixtures thereof.
9. The coated article of claim 1 , wherein the zirconia phase is dispersed in the alumina phase.
10. The coated article of claim 1 , wherein the ratio of aluminum to zirconium (Al/Zr) in the multiphase refractory layer is from 1.5 to 3.
11. The coated article of claim 1 , wherein zirconia is present in an amount of 20-40 weight percent of the multiphase refractory layer.
12. The coated article of claim 1 , wherein the zirconia phase primarily exhibits monoclinic crystalline structure.
13. The coated article of claim 1 , wherein the zirconia phase comprises a mixture of monoclinic and tetragonal crystalline phases.
14. The coated article of claim 13 , wherein the zirconia phase is 60-99.9% monoclinic.
15. The coated article of claim 13 , wherein the zirconia phase is 1-10% tetragonal.
16. The coated article of claim 1 , wherein the coating further comprises one or more inner layers between the multiphase refractory layer and substrate.
17. The coated article of claim 16 , wherein the one or more inner layers comprise one or more metallic elements selected from the group consisting of aluminum and metallic elements of Groups IVB, VB and VIB of the Periodic Table and one or more non-metallic elements selected from the group consisting of non-metallic elements of Groups IIIA, IVA, VA and VIA of the Periodic Table.
18. The coated article of claim 1 , wherein the coating further comprises one or more outer layers over the multiphase refractory layer.
19. The coated article of claim 18 , wherein the one or more outer layers comprise one or more metallic elements selected from the group consisting of aluminum and metallic elements of Groups IVB, VB and VIB of the Periodic Table and one or more non-metallic elements selected from the group consisting of non-metallic elements of Groups IIIA, IVA, VA and VIA of the Periodic Table.
20. The coated article of claim 1 , wherein the substrate is a cutting tool.
21. The coated article of claim 1 , wherein the cutting tool is a cutting insert or rotary cutting tool.
22. The coated article of claim 1 , where the substrate is cemented carbide, carbide, cermet, ceramic or steel.