Iron-based powder mixtures containing binder-lubricant

Claim 2

In an improved metallurgical powder composition of the kind comprising (a) an iron-based powder, (b) a minor amount of at least one alloying powder, and (c) at least about 0.005% by weight, based on the combined widths of (a) and (b), of an organic binder for the iron-based and alloying powders, the improvement comprising that at least 40% by weight of said organic binder is a polyalkylene oxide of the general formula ##STR3## where R is H, CH 3 , or C 2 H 5 ,, and n is the average number of repeating oxyalkylene unit sufficient to provide a number average molecular weight of at least about 7,000.

Claim 3

A composition of claim 1 in which the organic binder is present in an amount up to about 1% by weight, based on the total weight of the iron-based and alloying powders, and in which the iron-based powders have an average particle size of about 150 microns or less.

Claim 4

A composition of claim 2 in which said polyalkylene oxide comprises a homopolymers or copolymer of ethylene glycol.

Claim 5

A composition of claim 2 in which said polyalkylene oxide has a number average molecular weight of about 15,000-100,000 and in which said iron-based powders have an average particle size of about 70-100 microns.

Claim 6

A metallurgical powder composition of claim 4 in which said polyalkylene oxide is a homopolymer or copolymer of ethylene glycol and wherein the composition is at least as compressible as its unbonded analog at compaction pressures up to about 700 MPa.

Claim 7

A composition of claim 5 in which the weight ratio of binder to alloying powder in the composition is in accordance with the following schedule: ______________________________________ Weight Ratio of Binder to Density of Alloying Powder According to Alloying Particle Size Powders To Over Over (g/cm.sup.3) ˜10 μm 10 to ˜20 μm 20 μm ______________________________________ ≦2.5 0.125 0.125-0.175 ≧0.175 >2.5-4.5 0.100 0.100-0.125 ≧0.125 >4.5-7.0 0.050 0.050-0.075 0.075-0.125 >7.0 0.025 0.025-0.050 0.050-0.10 ______________________________________

Claim 8

A composition of claim 2 in which said polyalkylene oxide has an average molecular weight of about 15,000-35,000.

Claim 9

A composition of claim 7 in which said polyalkylene oxide constitutes at least bout 50% by weight of the organic binder.

Claim 10

A composition of claim 7 in which said polyalkylene oxide is a homopolymer or copolymer of ethylene glycol and constitutes at least about 75% by weight of the organic binder.

Claim 11

A metallurgical powder composition of claim 1 that is at least as compressible as its unbonded analog at compaction pressures up to about 700 MPa.

Claim 12

A composition of claim 1 in which the weight ratio of binder to alloying powder in the composition is in accordance with the following schedule: ______________________________________ Weight Ratio of Binder to Density of Alloying Powder According to Alloying Particle Size Powders To Over Over (g/cm.sup.3) ˜10 μm 10 to ˜20 μm 20 μm ______________________________________ ≦2.5 0.125 0.125-0.175 ≧0.175 >2.5-4.5 0.100 0.100-0.125 ≧0.125 >4.5-7.0 0.050 0.050-0.075 0.075-0.125 >7.0 0.025 0.025-0.050 0.050-0.10 ______________________________________

Claim 13

A metallurgical powder combustion of claim 11 that is at least as compressible as its unbonded analog at compaction pressures up to about 700 MPa.

Claim 14

A composition of claim 11 in which said polyalkylene oxide has an average molecular weight of at least about 75,000 and in which said organic binder consists essentially of about 60-95% by weight of said polyalkylene oxide and about 5-40% by weight of a plasticizer for said polyalkylene oxide.

Claim 15

A composition of claim 1 in which said polyalkylene oxide has an average molecular weight of at least about 75,000, and in which said organic binder consists essentially of about 60-95% by weight of said polyalkylene oxide and about 5-40% by weight of a plasticizer for said polyalkylene oxide.