Ceramic material and cutting tools made thereof
A ceramic material includes of β-sialon (Si (6-z) Al z O z N (8-z) ), polytype 15R, an intergranular phase, and yttrium. The polytype 15R includes twin grains.
1. A ceramic material consisting of:
β-sialon (Si (6-z) Al z O z N (8-z) ), polytype 15R, and intergranular phase, and yttrium, wherein:
z is the substitution rate in the β-sialon, wherein 0.0<z<4.2; and
the polytype 15R comprises twin grains.
2. The ceramic material according to claim 1 , wherein:
an amount of the polytype 15R is between 25% and 55%, as measured as a ratio of a height in a Cu-Kα X-ray diffraction pattern of 15R peak at a 2θ value of 34° and a height in the same diffraction pattern of a β-sialon peak at a 2θ value of 33°.
3. A cutting tool for machining a chip-forming metal, comprising:
the ceramic material according to claim 2 .
4. A cutting tool for machining a chip-forming metal, comprising:
the ceramic material according to claim 1 .
5. A ceramic material comprising:
β-sialon (Si (6-z) Al z O z N (8-z) ), polytype 15R, and intergranular phase, and yttrium, wherein:
z is the substitution rate in the β-sialon, wherein 0.0<z<4.2; and
the polytype 15R comprises twin grains.
6. The ceramic material according to claim 5 , wherein:
an amount of the polytype 15R is between 25% and 55%, as measured as a ratio of a height in a Cu-Kα X-ray diffraction pattern of 15R peak at a 2θ value of 34° and a height in the same diffraction pattern of a β-sialon peak at a 2θ value of 33°.
7. A cutting tool for machining a chip-forming metal, comprising:
the ceramic material according to claim 6 .
8. A cutting tool for machining a chip-forming metal, comprising:
the ceramic material according to claim 5 .
9. The ceramic material according to claim 5 , wherein:
1.3≤ z≤ 1.8.
10. The ceramic material according to claim 9 , wherein:
1.6≤ z≤ 1.7.
11. The ceramic material according to claim 5 , wherein the ceramic material is devoid of Mg.
12. The ceramic material according to claim 5 , comprising reaction products of Si 3 N 4 , AlN, Y 2 O 3 and Al 2 O 3 , but not MgO.
13. A ceramic material consisting essentially of:
β-sialon (Si (6-z) Al z O z N (8-z) ), polytype 15R, and intergranular phase, and yttrium, wherein:
z is the substitution rate in the β-sialon, wherein 0.0<z<4.2; and
the polytype 15R comprises twin grains.
14. The ceramic material according to claim 13 , wherein:
an amount of the polytype 15R is between 25% and 55%, as measured as a ratio of a height in a Cu-Kα X-ray diffraction pattern of 15R peak at a 2θ value of 34° and a height in the same diffraction pattern of a β-sialon peak at a 2θ value of 33°.
15. The ceramic material according to claim 13 , wherein:
1.3≤ z≤ 1.8.
16. The ceramic material according to claim 15 , wherein:
1.6≤ z≤ 1.7.
17. The ceramic material according to claim 13 , wherein the ceramic material is devoid of Mg.
18. The ceramic material according to claim 13 , consisting essentially of reaction products of Si 3 N 4 , AlN, Y 2 O 3 and Al 2 O 3 .
19. The ceramic material according to claim 13 , wherein each of the twin grains comprises bright bands and dark bands repeatedly stacked on one another.
20. The ceramic material according to claim 1 , wherein each of the twin grains comprises bright bands and dark bands repeatedly stacked on one another.
21. The ceramic material according to claim 5 , wherein each of the twin grains comprises bright bands and dark bands repeatedly stacked on one another.