Method for producing a powder-metallurgical product

1. A method for producing a powder-metallurgical product, comprising:

providing a powder mixture including:

a first hard phase, which includes 52 to 78% by weight of molybdenum, 0.4% to 2% by weight of silicon, 0 to 1.5% by weight of copper and a remaining weight proportion of iron and production-related contaminations;

a second hard phase including manganese, the second hard phase including 0.8% by weight or less of manganese and less than 0.1% by weight of carbon;

0 to 1.8% by weight of graphite;

0 to 5% by weight each of cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride and molybdenum;

0.1 to 1.8% by weight of each of a pressing aid and a flow improver; and

a remaining proportion of a total weight of the powder mixture is an iron-base powder;

forming the powder mixture into a green body; and

sintering the green body to form a resulting powder-metallurgical product.

2. The method according to claim 1 , wherein one of:

the second hard phase further includes 25 to 30% by weight of molybdenum, 6 to 11% by weight of chromium, 2 to 4.5% by weight of silicon, 0 to 5% by weight of iron, and a remaining proportion of a total weight of the second hard phase is cobalt and production-related contaminations; and

the second hard phase further includes 26 to 32% by weight of molybdenum, 12 to 19% by weight of chromium, 2 to 5% by weight of silicon, 0 to 5% by weight of cobalt, and a remaining proportion of a total weight of the second hard phase is iron and production-relating contaminations.

3. The method according to claim 1 , wherein one of:

the first hard phase and the second hard phase in total amount to 10 to 45% of the total weight of the powder mixture and a ratio of a weight proportion of the first hard phase to a weight proportion of the second hard phase amounts to between 3 to 1 and 1 to 3; and

the first hard phase and the second hard phase in total amount to 22 to 40% of the total weight of the powder mixture and a ratio of a weight proportion of the first hard phase to a weight proportion of the second hard phase amounts to between 2 to 1 and 1 to 2.

4. The method according to claim 1 , wherein the iron-base powder includes at least one tool steel powder.

5. The method according to claim 1 , wherein 30 to 70% by weight of the iron-base powder is composed of a powder including 0.8 to 1.3% by weight of carbon, 3 to 5% by weight of chromium, 0 to 1% by weight of cobalt, 0 to 0.5% by weight of manganese, 3 to 7% by weight of molybdenum, 0 to 1% by weight of silicon, 2 to 4% by weight of vanadium, 5 to 7.5% by weight of tungsten, and a remaining proportion of a total weight of the powder is iron and production-related contaminations.

6. The method according to claim 1 , wherein forming the powder mixture into a green body includes uni-axial pressing the powder mixture to a green density of 6.3 g/cm 3 to 7.5 g/cm 3 .

7. The method according to claim 1 , further comprising infiltrating a plurality of pores in the green body with a copper base infiltrant when sintering the green body.

8. The method according to claim 1 , wherein the green body is sintered at a temperature of 1,065° C. to 1,195° C.

9. The method according to claim 1 , wherein at least one of:

the powder mixture includes 0.15% by weight to 5% by weight of tri-iron phosphide;

the powder mixture includes more than 0% by weight to 5% by weight of bronze; and

the powder mixture includes more than 0% by weight to 5% by weight of phosphorous.

10. The method according to claim 1 , wherein the powder mixture is formed into the green body via pressing.

11. The method according to claim 1 , wherein the resulting powder-metallurgical product is one of a bearing, a sealing element, a sliding element, a valve component, and a valve seat ring.

12. The method according to claim 1 , wherein a total weight of the resulting powder-metallurgical product includes 0.5 to 1.8% by weight of carbon, 2 to 9% by weight of chromium, 4 to 16% by weight of cobalt, 0 to 1.6% by weight of manganese, 10 to 22% by weight of molybdenum, 0 to 2% by weight of silicon, 0.5 to 6% by weight of vanadium, 1 to 8% by weight of tungsten, 5 to 25% by weight of copper, 0 to 2% by weight of calcium, 0 to 1.5% by weight of sulphur, 0 to 5% nickel, and a remaining proportion of the total weight of the resulting powder-metallurgical product is iron and production-related contaminations.

13. The method according to claim 1 , wherein a total weight of the resulting powder-metallurgical product includes 0.7 to 1.5% by weight of carbon, 2 to 5% by weight of chromium, 8 to 12% by weight of cobalt, 0 to 1% by weight of manganese, 12 to 18% by weight of molybdenum, 0 to 2% by weight of silicon, 1 to 3% by weight of vanadium, 2 to 4% by weight of tungsten, 10 to 20% by weight of copper, 0 to 0.5% by weight of calcium, 0 to 1% by weight of sulphur, 0 to 3% by weight of nickel, and a remaining proportion of the total weight of the resulting powder-metallurgical product is iron and production-related contaminations.

14. The method according to claim 1 , wherein the pressing aid and the flow improver collectively defined 1.8% by weight or less of the powder mixture.

15. The method according to claim 1 , wherein the powder mixture includes 0.15% by weight to 5% by weight of tri-iron phosphide.

16. The method according to claim 1 , wherein the powder mixture includes each of graphite, cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride, molybdenum, the pressing aid, the flow improver, and the iron-base powder.

17. The method according to claim 1 , wherein:

the first hard phase and the second hard phase in total amount to 10 to 45% of the total weight of the powder mixture; and

a ratio of a weight proportion of the first hard phase to a weight proportion of the second hard phase is one of 3:1, 2:1, 1:2, and 1:3.

18. A method for producing a powder-metallurgical product, comprising:

providing a powder mixture;

forming the powder mixture into a green body; and

sintering the green body to form a resulting powder-metallurgical product;

wherein the powder mixture includes:

a first hard phase, which includes 52 to 78% by weight of molybdenum, 0 to 2% by weight of silicon, 0 to 1.5% by weight of copper and a remaining weight proportion of iron and production-related contaminations;

a second hard phase, which includes 0 to 0.8% by weight of manganese and less than 0.1% by weight of carbon;

0 to 1.8% by weight of graphite;

0 to 5% by weight each of cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride and molybdenum;

0.1 to 1.8% by weight of each of a pressing aid and a flow improver; and

a remaining proportion of a total weight of the powder mixture is an iron-base powder; and

wherein 30 to 70% by weight of the iron-base powder is composed of a powder including 0.8 to 1.3% by weight of carbon, 3 to 5% by weight of chromium, 0 to 1% by weight of cobalt, 0 to 0.5% by weight of manganese, 3 to 7% by weight of molybdenum, 0 to 1% by weight of silicon, 2 to 4% by weight of vanadium, 5 to 7.5% by weight of tungsten, and a remaining proportion of a total weight of the powder is iron and production-related contaminations.

19. A method for producing a powder-metallurgical product, comprising:

providing a powder mixture including a first hard phase, a second hard phase, graphite, cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride, molybdenum, a pressing aid, a flow improver, and an iron-base powder, the first hard phase including molybdenum, silicon, copper, and iron, and the second hard phase including manganese;

forming the powder mixture into a green body; and

sintering the green body to form a resulting powder-metallurgical product;

wherein the first hard phase includes 52 to 78% by weight of molybdenum, 2% by weight or less of silicon, 1.5% by weight or less of copper, and a remaining weight proportion of iron and production-related contaminations;

wherein the second hard phase includes 0.8% by weight or less of manganese and less than 0.1% by weight of carbon; and

wherein:

the first hard phase and the second hard phase collectively amount to 10 to 45% by weight of the powder mixture;

graphite amounts to 1.8% by weight or less of the powder mixture;

each of cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride, and molybdenum amount to 5% by weight or less of the powder mixture;

each of the pressing aid and the flow improver amount to 0.1 to 1.8% by weight of the powder mixture; and

the iron-base powder forms the remainder of the powder mixture.

20. A method for producing a powder-metallurgical product, comprising:

providing a powder mixture;

forming the powder mixture into a green body; and

sintering the green body to form a resulting powder-metallurgical product including carbon, chromium, cobalt, manganese, molybdenum, silicon, vanadium, tungsten, copper, calcium, sulphur, nickel, and iron;

wherein the powder mixture includes:

a first hard phase, which includes 52 to 78% by weight of molybdenum, 0 to 2% by weight of silicon, 0 to 1.5% by weight of copper and a remaining weight proportion of iron and production-related contaminations;

a second hard phase, which includes 0 to 0.8% by weight of manganese and less than 0.1% by weight of carbon;

0 to 1.8% by weight of graphite;

0 to 5% by weight each of cobalt, tri-iron phosphide, copper, bronze, phosphorous, sulphur, calcium fluoride and molybdenum;

0.1 to 1.8% by weight of each of a pressing aid and a flow improver; and

a remaining proportion of a total weight of the powder mixture is an iron-base powder; and

wherein the resulting powder-metallurgical product includes 0.7 to 1.5% by weight of carbon, 2 to 5% by weight of chromium, 8 to 12% by weight of cobalt, 1% by weight or less of manganese, 12 to 18% by weight of molybdenum, 2% by weight or less of silicon, 1 to 3% by weight of vanadium, 2 to 4% by weight of tungsten, 10 to 20% by weight of copper, 0.5% by weight or less of calcium, 1% by weight or less of sulphur, 3% by weight or less of nickel, and a remainder iron and production-related contaminations.