Metal powder composition and preparation thereof
AssigneeHöganäs AB
InventorsMats Larsson, Åsa Ahlin, Maria Ramstedt, Hilmar Vidarsson
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Abstract
The invention concerns an improved segregation-resistant and dust-resistant metallurgical composition for making compacted parts, comprising at least about 80 percent by weight of an iron or iron-based powder; at least one alloying powder; and (c) about 0.05 to about 2 percent by weight of a binding/lubricating combination of polyethylene wax and ethylene bis-stearamide, the polyethylene wax having a weight average molecular weight below about 1000 and a melting point below that of ethylene bis-stearamide, and being present in amount between 10 and 90% by weight of the binding/lubricating combination.
Claims20
An improved segregation-resistant and dust-resistant metallurgical composition for making compacted parts, comprising:
- (a) at least about 80 percent by weight of an iron or iron-based powder;
- (b) at least one alloying element powder;
- and
- (c) about 0.05 to about 2 percent by weight of a binding/lubricating combination of polyethylene wax and ethylene bis-stearamide, the polyethylene wax having a weight average molecular weight below about 1000 and a melting point below that of ethylene bis-stearamide, and being present in amount between 10 and 90% by weight of the binding/lubricating combination,
- wherein the particles of the iron or iron-based powder are coated with a layer of the polyethylene wax binding particles of the alloying element(s) and particles of the ethylene bis-stearamide.
Method of preparing an improved segregation-resistant and dust-resistant metallurgical composition containing alloying powder bound to iron-based powder comprising the steps of
- mixing and heating an iron or iron-based powder, an alloying element powder, ethylene bis-stearamide and a pulverulent polyethylene wax and optionally a fatty acid to a temperature above the melting point of the polyethylene wax and below the melting point of the ethylene bis-stearamide
- cooling the obtained mixture to a temperature below the melting point of the polyethylene wax for a period of time sufficient to solidify the polyethylene wax and bind the particles of the alloying element to the iron-containing particles in order to form aggregate particles, and optionally
- mixing a pulverulent flow agent having a particle size below 200 nanometers with the obtained mixture in an amount between 0.005 to about 2% by weight of the composition.
An improved segregation-resistant and dust-resistant metallurgical composition for making compacted parts, comprising:
- (a) at least about 80 percent by weight of an iron or iron-based powder;
- (b) at least one alloying element powder;
- and
- (c) about 0.05 to about 2 percent by weight of a binding/lubricating combination of polyethylene wax and ethylene bis-stearamide, the polyethylene wax having a weight average molecular weight below about 1000 and a melting point below that of ethylene bis-stearamide, and being present in amount between 10 and 90% by weight of the binding/lubricating combination,
- wherein a mixture of the iron or iron-based powder, alloying element powder, ethylene bis-stearamide and polyethylene wax having been heated to a temperature above the melting point of the polyethylene wax and below the melting point of the ethylene bis-stearamide and cooled to a temperature below the melting point of the polyethylene wax for a period of time sufficient to solidify the polyethylene wax.
Dependencies are inferred from the claim text.