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US 5,423,899 AGranted
Dispersion alloyed hard metal composites and method for producing same
AssigneeNewcomer Products, Inc.
InventorsJack Krall, Anders Olsson
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AssigneeNewcomer Products, Inc.
InventorsJack Krall, Anders Olsson
Estimating the term…
A method for forming a sintered hard metal composite is provided in which unsintered nodules of a pre-blended hard metal powder of a first grade are uniformly dispersed into unsintered nodules of a pre-blended hard metal composite of a second grade. The pre-blended hard metal powders form a composite powder blend which is subsequently pressed and sintered to form the dispersion alloyed hard metal composite. A sufficient amount of pressing lubricant is provided to one of the pre-blended hard metal powders so that each of the hard metal powders shrinks at approximately the same rate relative to the application of pressure during the compacting process. The pressing lubricant is added to that hard metal powder which shrinks more during sintering. By providing uniform shrinkage of the constituent powder grades, migration of the binder from one constituent grade to the other constituent grade is minimized, thereby allowing the composite powder blend to achieve superior properties because each of the constituent grades maintains its own integrity. In addition, the uniform shrinkage of the constituent powders prevents irregular surface conditions of the "as sintered" surface.
A method for forming a sintered hard metal composite comprising the steps of:
A method for forming a sintered hard metal composite comprising the steps of:
A method for forming a sintered hard metal composite comprising the steps of:
A sintered hard metal composite comprising unsintered nodules of a pre-blended hard metal powder of a first grade uniformly dispersed among unsintered nodules of a pre-blended hard metal powder of second grade, said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade having distinctively different properties from each other, wherein the integrity of the constituent grades is maintained after sintering, and the resulting composite exhibits hardness and toughness properties of the hard metal powder of the first grade and the hard metal powder of the second grade, wherein at least one of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade is processed such that each said hard metal powder shrinks by approximately the same rate when compacted and sintered.
A sintered hard metal composite comprising unsintered nodules of a pre-blended hard metal powder of a first grade uniformly dispersed among unsintered nodules of a pre-blended hard metal powder of second grade, said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade having distinctively different properties from each other, wherein the integrity of the constituent grades is maintained after sintering, and the resulting composite exhibits hardness and toughness properties of the hard metal powder of the first grade and the hard metal powder of the second grade, wherein a stearate compound pressing lubricant is provided in at least one of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade.
A sintered hard metal composite comprising unsintered nodules of a pre-blended hard metal powder of a first grade uniformly dispersed among unsintered nodules of a pre-blended hard metal powder of second grade, said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade having distinctively different properties from each other, wherein the integrity of the constituent grades is maintained after sintering, and the resulting composite exhibits hardness and toughness properties of the hard metal powder of the first grade and the hard metal powder of the second grade, wherein a pressing lubricant is provided in at least one of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade, wherein said each of said hard metal powder of a first grade and said hard metal powder of a second grade comprise tungsten carbide and a binder, said pressing lubricant providing sufficient shrinkage adjustment of said at least one of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade to prevent migration of said binder from which of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade that shrinks less relative to the application of pressure.
A sintered hard metal composite comprising unsintered nodules of a pre-blended hard metal powder of a first grade having a binder provided therein uniformly dispersed among unsintered nodules of a pre-blended hard metal powder of a second different grade having a binder provided therein, wherein a sufficient amount of pressing lubricant is provided in at least one of said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade to control the binder migration between said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade resulting from the shrinkage difference between said pre-blended hard metal powder of a first grade and said pre-blended hard metal powder of a second grade during sintering.
A method for forming a sintered hard metal composite having predetermined composition and properties comprising the steps of:
A method for forming a sintered hard metal composite having predetermined composition and properties comprising the steps of:
A method for forming a sintered hard metal composite having predetermined composition and properties comprising the steps of:
Dependencies are inferred from the claim text.