Layered construction of metallic materials
The present disclosure is directed at alloys and method for layer-by-layer deposition of metallic alloys on a substrate. The resulting deposition provides for relatively high hardness metallic parts with associated wear resistance. Applications for the metallic parts include pumps, valves and/or bearings.
1. A method of layer-by-layer construction of a metallic part comprising:
supplying particles of an alloy, said alloy consisting of Fe in an amount ranging from 54.0 wt. % to 78.0 wt. %, B in an amount ranging from 3.0 wt. % to 5.0 wt. %, Cr in an amount ranging from 14.0 wt. % to 20.0 wt. %, C in an amount ranging from 0.5 wt. % to 7.0 wt. %, optionally Mo in an amount up to 11.0 wt. %, optionally Mn in an amount up to 2.5 wt. %, optionally Nb in an amount up to 4.5 wt. %, optionally Si in an amount up to 2.0 wt. %, optionally W in an amount up to 7.0 wt. %;
supplying a substrate;
applying a first layer of said particles onto said substrate;
irradiating said first layer of particles with a laser or electron beam to cause at least partial melting of said first layer of particles to form a first molten layer of said alloy;
cooling said first molten layer to form a first solidified layer of said alloy with an as-formed thickness of 5.0 to 200.0 microns
applying a second layer of said particles to said first solidified layer;
irradiating said second layer of particles with a laser or an electron beam to cause at least partial melting of said second layer of particles to form a second molten layer of said alloy;
cooling said second molten layer to form a second solidified layer of said alloy with an as-formed thickness of 5.0 to 200.0 microns; and
removing said substrate by electric-discharge machining or mechanical sawing to form a free-standing metallic part;
wherein:
said first solidified layer, said second solidified layer, or said first and second solidified layers exhibit a hardness in the range of 900-1800 HV; and
said first and second solidified layers contain:
(a) borocarbide and carbide phases at a size of 0.1 microns to 10.0 microns; and
(b) grains with a grain size of 0.1 microns to 10.0 microns.
2. The method of claim 1 wherein said alloy includes said Mo in an amount ranging from 0.1 wt. % to 11.0 wt. %, said Si in an amount ranging from 0.1 wt % to 2.0 wt. %, and said W in an amount ranging from 0.1 wt. % to 7.0 wt. %.
3. The method of claim 1 wherein said alloy includes said Nb in an amount ranging from 0.1 wt. % to 4.5 wt. %.
4. The method of claim 1 wherein said alloy includes said Mo in an amount ranging from 0.1 wt. % to 11.0 wt. %.
5. The method of claim 1 wherein said particles of said alloy comprises particles having a diameter in the range of 5.0 microns to 75.0 microns.
6. The method of claim 1 wherein said substrate has a first thermal expansion coefficient and said metal alloy has a second thermal expansion coefficient, wherein the first thermal expansion coefficient differs from the second thermal expansion coefficient by less than 2 μm/m·° C.
7. The method of claim 1 wherein when the second molten layer is formed, the first solidified layer has a temperature in the range of 25° C. to 1400° C., and the second molten layer has a temperature in the range of 900° C. to 2000° C.
8. The method of claim 1 wherein the first and second solidified layers each have an as-formed thickness in the range of 5.0 microns to 50.0 mm.
9. The method of claim 1 wherein said part has a volume and 95% or more of said volume of said part comprises metallic regions with the remainder voids.
10. The method of claim 1 wherein said part has a volume and 97% or more of said volume of said part comprises metallic regions with the remainder voids.
11. The method of claim 1 wherein said part has a volume and 99% to 100% of said volume of said part comprises metallic regions.
12. The method of claim 1 wherein said first solidified layer, said second solidified layer, or said first and second solidified layers have an ASTM G65-10 Procedure A (2010) wear resistance of 24.0 mm 3 at +/−5.0 mm 3 .
13. The method of claim 1 wherein said metallic part comprises a pump, valve or bearing.
14. A method of layer-by-layer construction of a metallic part comprising:
supplying particles of an alloy, said alloy consisting of Fe in an amount ranging from 54.0 wt. % to 78.0 wt. %, B in an amount ranging from 3.0 wt. % to 5.0 wt. %, Cr in an amount ranging from 14.0 wt. % to 20.0 wt. %, C in an amount ranging from 0.5 wt. % to 7.0 wt. %, optionally Mo in an amount up to 11.0 wt. %, optionally Mn in an amount up to 2.5 wt. %, optionally Nb in an amount up to 4.5 wt. %, optionally Si in an amount up to 2.0 wt. %, optionally W in an amount up to 7.0 wt. %;
supplying a substrate, wherein said substrate has a first thermal expansion coefficient, said alloy has a second thermal expansion coefficient, wherein the first thermal expansion coefficient differs from the second thermal expansion coefficient by less than 2 μm/m·° C.;
applying a first layer of said particles onto said substrate;
irradiating said first layer of particles with a laser or electron beam to cause at least partial melting of said first layer of particles to form a first molten layer of said alloy;
cooling said first molten layer to form a first solidified layer of said alloy with an as-formed thickness of 5.0 to 200.0 microns;
applying a second layer of said particles to said first solidified layer;
irradiating said second layer of particles with a laser or an electron beam to cause at least partial melting of said second layer of particles to form a second molten layer of said alloy;
cooling said second molten layer to form a second solidified layer of said alloy with an as-formed thickness of 5.0 to 200.0 microns; and
optionally removing said substrate to form a free-standing metallic part;
wherein:
said first solidified layer, said second solidified layer, or said first and second solidified layers exhibit a hardness in the range of 900-1800 HV; and
said first and second solidified layers contain:
(a) borocarbide and carbide phases at a size of 0.1 microns to 10.0 microns; and
(b) grains with a grain size of 0.1 microns to 10.0 microns.
15. The method of claim 14 , wherein said irradiating is performed with an electron beam.
16. The method of claim 1 , wherein said first solidified layer, said second solidified layer, or said first and second solidified layers exhibit a hardness in the range of 1200-1600 HV.
17. The method of claim 14 , wherein said first solidified layer, said second solidified layer, or said first and second solidified layers exhibit a hardness in the range of 1200-1600 HV.