Metal powder mixtures, sintered article produced therefrom and process for producing same

Claim 2

A metallic powder mixture for the production of highly densified sintered bodies which exhibit high resistance to wear, corrosion and alternating thermal stresses, which comprises 95 to 99.5% of a base alloy powder and 0.5 to 5% of an additive alloy powder comprising a nickel base alloy which contains from 0.1 to 4% boron and 0.1 to 6% silicon, said additive alloy having a melting point which is lower than the melting point of said base alloy such that when pressed and sintered at a temperature above the melting temperature of said additive alloy and below the melting temperature of said base alloy for about 20 to about 40 minutes, a sintered body is produced having a density of at least 95% of the theoretical density.

Claim 3

A metallic powder mixture as set forth in claim 1, wherein said additive alloy comprises: ______________________________________ carbon 1% maximum chromium 5-18% boron .1-4% silicon .1-6% iron 6% maximum nickel and incidental the balance. impurities ______________________________________

Claim 4

A metallic powder mixture in accordance with claim 1, wherein said base alloy comprises nickel as the major component.

Claim 5

A metallic powder mixture in accordance with claim 2, wherein said base alloy comprises nickel as the major component.

Claim 6

A metallic powder mixture in accordance with claim 1, wherein said base alloy comprises: ______________________________________ carbon 1.25% maximum cobalt 9-11% chromium 27-31% tungsten 13-16% iron 8% maximum silicon 1% maximum nickel and incidental the balance. impurites ______________________________________

Claim 7

A metallic powder mixture in accordance with claim 2, wherein said base alloy comprises: ______________________________________ carbon 1.25% maximum cobalt 9-11% chromium 27-31% tungsten 13-16% iron 8% maximum silicon 1% maximum nickel and incidental the balance. impurites ______________________________________

Claim 8

A metal powder mixture for the production of sintered bodies having a density of at least 95% of theoretical density, wherein the sintered bodies exhibit high corrosion-, wear-, heat-, and abrasion-resistance, which comprises from about 95 to 99.5% of a base powder alloy consisting essentially of up to 1.25% carbon, from about 9-11% cobalt, from about 13-16% tungsten, from about 27-31% chormium, up to 1% silicon, up to 8% iron, and the balance nickel and impurities, and from about 0.5 to 5% of a low melting point additive alloy consisting essentially of up to 1% carbon, up to 6% iron, from about 0.1-6% silicon, from about 0.1-4% boron, from about 5-18% chromium, and the balance nickel and impurities.

Claim 9

A metal powder mixture for the production of sintered bodies having a density of at least 95% of theoretical density, wherein the sintered bodies exhibit high corrosion-, wear-, heat-, and abrasion-resistance, which comprises from about 95 to 99.5% of a base powder alloy consisting essentially of up to 1.25% carbon, from about 9-11% cobalt, from about 13-16% tungsten, from about 27-31% chormium, up to 1% silicon, up to 8% iron, and the balance nickel and impurities, and from about 0.5 to 5% of a low melting point additive alloy consisting essentially of up to 1% carbon, up to 6% iron, from about 0.1-6% silicon, from about 0.1-4% boron, from about 5-18% chromium, and the balance nickel and impurities.

Claim 10

A sintered article prepared from the metal powder mixture of claim 1.

Claim 11

A sintered article prepared from the metal powder mixture of claim 1.

Claim 12

A sintered article prepared from the metal powder mixture of claim 2.

Claim 13

A sintered article prepared from the metal powder mixture of claim 5.

Claim 14

A sintered article prepared from the metal powder mixture of claim 6.

Claim 15

A sintered article prepared from the metal powder mixture of claim 8.

Claim 16

A process for preparing sintered articles of high density comprising: mixing from about 95 to 99.5% of a base alloy powder consisting essentially of up to 1.25% carbon, from about 9-11% cobalt, from about 13-16% tungsten, from about 27-31% chromium, up to 1% silicon, up to 8% iron, and the balance nickel and impurities, with from about 0.5 to 5% of a low melting additive alloy powder consisting essentially of up to 1% carbon, up to 6% iron, from about 0.1-6% silicon, from about 0.1-4% boron, from about 5-18% chromium, and the balance nickel and impurities; compacting said mixture to a green density of from about 6.8 to about 7.2 g/cm 3 ; and sintering said mixture at a temperature of from about 1000° to about 1300° C., for a duration of from 20 to about 40 minutes.

Claim 17

A process for preparing sintered articles of high density comprising: mixing from about 95 to 99.5% of a base alloy powder consisting essentially of up to 1.25% carbon, from about 9-11% cobalt, from about 13-16% tungsten, from about 27-31% chromium, up to 1% silicon, up to 8% iron, and the balance nickel and impurities, with from about 0.5 to 5% of a low melting additive alloy powder consisting essentially of up to 1% carbon, up to 6% iron, from about 0.1-6% silicon, from about 0.1-4% boron, from about 5-18% chromium, and the balance nickel and impurities; compacting said mixture to a green density of from about 6.8 to about 7.2 g/cm 3 ; and sintering said mixture at a temperature of from about 1000° to about 1300° C., for a duration of from 20 to about 40 minutes.