Process for the preparation of pre-alloyed powders for diamond tools, and the powders so obtained
AssigneeUmicore AG & Co. KG
InventorThierry COMMEAU
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Abstract
The invention concerns pre-alloyed powders useful for the manufacture of metal-bonded diamond tools. A process for the synthesis of such powders is presented, characterized in that at least a major part of the phosphor is introduced by adding an aqueous solution of a phosphorus salt to one or more of the metal-bearing compounds. The powder can have a low cobalt content, or even be cobalt-free, yet remain suitable for the production of diamond-loaded segments having harness and bending characteristics approaching or exceeding that of cobalt.
Claims16
1-15. (canceled)
A process for the synthesis of pre-alloyed powders for the manufacture of diamond tools, comprising the steps of:
- preparing a mixture of metal-bearing compounds in solid form containing one or more of Fe, Cu, Ni, Co, Sn, P, Mo, W, wherein the relative metallic concentrations are selected so as to obtain a pre-alloyed powder according to the formula FeaCubNicCodSnePfMogWh, with, in weight %, a>50, 5<b<25, c<20, d<5, e<5, 0.5<f<5, 0.5<g+h<5, and a+b+c+d+e+f+g+h>95%;
- hydrogen reduction of the precursor mixture;
- comminuting the reduced precursor mixture, thereby obtaining a pre-alloyed powder;
- wherein at least a major part of the phosphorus is introduced by adding an aqueous solution of a phosphorus salt to one or more of the metal-bearing compounds or to their mixture.
A metal powder according to the formula FeaCubNicCodSnePfMogWhAxOy, with, in weight %, a>50, 5<b<25, c<20, d<5, e<5, 0.5<f<5, 0.5<g+h<5, x+y<5, and a+b+c+d+e+f+g+h+x+y=100;
- whereby A represents one or more elements having a Gibbs free energy of oxidation at 700° C. which is lower than the Gibbs free energy of oxidation of Mo at 700° C.
A precursor for preparing a metal powder, the precursor comprising
- one or more P-bearing compounds, wherein P is present in an oxidised state, and
- metal-bearing compounds bearing Fe, Cu and one or both of Mo and W, wherein the Fe, Cu and one or both of Mo and W are present in the metal bearing compounds in an oxidised state.
Dependencies are inferred from the claim text.