Process for making composite bearing material

Claim 2

A process for making a composite bearing material comprising a steel backing strip having a copper-lead bearing alloy lining tenaciously bonded to at least one side thereof which comprises the steps of applying a layer of a prealloyed powder on the surface of a steel backing strip, said prealloyed powder containing about 64% to about 88% copper, about 8% to about 35% lead and up to about 10% tin and ranging in average particle size of from about one micron up to about 147 microns, heating the prealloyed powder layer and said backing strip to a temperature of about 1450° F to about 1600° F in a reducing atmosphere for a period of time sufficient to effect a liquid phase sintering of the powder and the formation of a bond between said layer and said backing strip, cooling the sintered layer and backing strip to about 1000° F to about 1200° F in a protective atmosphere and applying pressure thereto to effect a substantially complete densification of said powder layer and a further diffusion bonding of the powder particles to each other and to the surface of said backing strip, and thereafter cooling the composite strip in a protective environment to a temperature below about 800° F.

Claim 3

The process as defined in claim 1, in which the powder layer is applied on said backing strip in a thickness of about 0.020 to about 0.070 inch.

Claim 4

The process as defined in claim 1, in which said prealloyed powder contains particles of a substantially spherical configuration which are of a size randomly distributed over the permissible size range.

Claim 5

The process as defined in claim 1, in which the application of pressure to the sintered powder layer is achieved by a roll compaction in a manner to achieve a powder layer density of substantially 100% density.

Claim 6

The process as defined in claim 4, in which the roll compaction is performed to apply a pressure of about 5000 psi on the powder layer.

Claim 7

The process as defined in claim 1, wherein cooling of the composite material is achieved by passing it through a molten lead bath.

Claim 8

The process as defined in claim 1, including the further step of precleaning said surface of said steel backing strip to provide a metallurgically clean surface prior to the step of applying a layer of a prealloyed powder thereon.

Claim 9

The process as defined in claim 1, in which said prealloyed powder is comprised of particles of an average size randomly distributed over the range of from 1 micron to about 147 microns with about 50% thereof less than 44 microns.

Claim 10

The process as defined in claim 1, in which the step of cooling the composite strip in a protective environment to a temperature below about 800° F is performed by first cooling the composite strip in a protective atmosphere to a temperature of from about 900° F to about 1000° F and thereafter introducing the composite strip into a molten lead bath.

Claim 11

A process for making a composite bearing material comprising a steel backing strip having a copper-lead bearing alloy lining tenaciously bonded to at least one side thereof which comprises the steps of applying a layer of a prealloyed powder on the surface of a steel backing strip in a thickness of about 0.020 to about 0.070 inch, said prealloyed powder containing about 64% to about 88% copper, about 8% to about 35% lead and up to about 10% tin and ranging in average particle size of from about 1 micron up to about 147 microns with 50% of the particles being less than 44 microns, heating the prealloyed powder layer and said backing strip to a temperature of about 1450° F to about 1600° F in a reducing atmosphere for a period of time sufficient to effect a liquid phase sintering of the powder and the formation of a bond between said layer and said backing strip, cooling the sintered layer and backing strip to about 1000° F to about 1200° F in a protective atmosphere and applying pressure thereto by a roll compaction to effect densification of said powder layer to substantially 100% theoretical density and a further diffusion bonding of the powder particles to each other and to the surface of said backing strip forming a composite strip, cooling the composite strip in a protective atmosphere to a temperature of from about 900° F to about 1000° F and thereafter passing the composite strip through a molten lead bath to effect a cooling thereof to a temperature below about 800° F.

Claim 12

A process for making a composite bearing material comprising a steel backing strip having a copper-lead bearing alloy lining tenaciously bonded to at least one side thereof which comprises the steps of applying a layer of a prealloyed powder on the surface of a steel backing strip in a thickness of about 0.020 to about 0.070 inch, said prealloyed powder containing about 64% to about 88% copper, about 8% to about 35% lead and up to about 10% tin and ranging in average particle size of from about 1 micron up to about 147 microns with 50% of the particles being less than 44 microns, heating the prealloyed powder layer and said backing strip to a temperature of about 1450° F to about 1600° F in a reducing atmosphere for a period of time sufficient to effect a liquid phase sintering of the powder and the formation of a bond between said layer and said backing strip, cooling the sintered layer and backing strip to about 1000° F to about 1200° F in a protective atmosphere and applying pressure thereto by a roll compaction to effect densification of said powder layer to substantially 100% theoretical density and a further diffusion bonding of the powder particles to each other and to the surface of said backing strip forming a composite strip, cooling the composite strip in a protective atmosphere to a temperature of from about 900° F to about 1000° F and thereafter passing the composite strip through a molten lead bath to effect a cooling thereof to a temperature below about 800° F.