Cermet electrode material
A cermet material includes as mass percentages, at least: 50% to 90% of a metallic phase containing an alloy of copper (Cu) and nickel (Ni), and 10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of Ni: 0.2%≤Ni≤17%. An electrode, preferably an anode, may include this cermet material.
1. Cermet material comprising as mass percentages, at least:
50% to 90% of a metallic phase which contains at least one alloy of copper (Cu) and nickel (Ni), said at least one alloy comprising as percentages by mass:
35% to 75% of nickel, and
25% to 65% of copper, and
10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of nickel: 0.2%≤Ni≤17%.
2. Cermet material according to claim 1 , characterized in that the at least one alloy of copper (Cu) and nickel (Ni) contains iron (Fe), the mass percentage of iron in said alloy not exceeding 20%.
3. Cermet material, comprising a cermet material according to claim 2 which is coated completely or partially with a protective layer of composition Ni 0.9 M y Fe 2.1-y O 4 .
4. Cermet material according to claim 3 , characterized in that a thickness of the protective layer is between 15 and 30 μm.
5. Cermet material according to claim 2 , characterized in that the percentage by mass of iron in the alloy of copper (Cu) and nickel (Ni) is between 2% and 15%.
6. Cermet material according to claim 1 , characterized in that the oxide phase further contains at least one metal (M) selected from aluminum (Al), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta), yttrium (Y), and hafnium (Hf).
7. Cermet material according to claim 1 , characterized in that said oxide phase comprises:
a monoxide phase of composition Ni x M y Fe 1-x-y O with the following proportions by mass:
0.3%≤Ni≤17%,
60%≤Fe≤78%, and
0≤M≤10%,
and/or
a nickel ferrite oxide phase of composition Ni x M y Fe 3-x-y O 4 with the following proportions by mass:
0.2%≤Ni≤13%,
60%≤Fe≤72%,
0≤M≤8%,
M being a metal selected from aluminum (Al), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta), yttrium (Y), hafnium (Hf) or a combination of these metals.
8. Cermet material according to claim 7 , characterized in that when said oxide phase comprises a nickel ferrite oxide phase, said nickel oxide ferrite phase is of composition Ni x M y Fe 3-x-y O 4 with the following mass proportions:
0.2%≤Ni≤10%,
63%≤Fe≤72%, and
0≤M≤4%.
9. Cermet material according to claim 8 , characterized in that said nickel oxide ferrite phase has the following mass proportions:
0.2%≤Ni≤5%,
68%≤Fe≤72%, and
0≤M≤4%.
10. Cermet material according to claim 7 , characterized in that when the oxide phase of the cermet material comprises a monoxide phase, said monoxide phase is of composition Ni x M y Fe 1-x-y O with the following mass proportions:
0.3%≤Ni≤13%,
65%≤Fe≤78%, and
0≤M≤4%.
11. Cermet material according to claim 10 , characterized in that said monoxide phase has the following mass proportions:
0.3%≤Ni≤8%,
70%≤Fe≤78%, and
0≤M≤4%.
12. Cermet material according to claim 1 , characterized in that the metallic phase further comprises at least one rare earth element selected from yttrium (Y), cerium (Ce), lanthanum (La) and neodymium (Nd).
13. Cermet material obtained after a pre-oxidation treatment of a cermet material according to claim 1 .
14. Cermet material according to claim 13 , characterized in that the pre-oxidation treatment is carried out in air between 900° C. and 1000° C. for a time between 2 and 10 hours.
15. Cermet material according to claim 1 , characterized in that the mass percentage of the metallic phase is 60% to 80% and the mass percentage of the oxide phase is 20% to 40%.
16. Cermet material according to claim 1 , characterized in that the percentage by mass of nickel is 40% to 60% and the percentage by mass of copper is 40% to 55% in the alloy of copper (Cu) and nickel (Ni).
17. Electrode comprising a metallic core covered wholly or partially by at least one layer comprising a cermet material comprising as mass percentages:
50% to 90% of a metallic phase which contains at least one alloy of copper (Cu) and nickel (Ni), said at least one alloy comprising as percentages by mass:
35% to 75% of nickel, and
25% to 65% of copper, and
10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of nickel: 0.2%≤Ni≤17%.
18. Electrode according to claim 17 , characterized in that said metallic core comprises at least one alloy of nickel (Ni) and iron (Fe), with proportions by mass of Ni and Fe being the following:
40%≤Ni≤85%, and
15%≤Fe≤60%.
19. Electrode according to claim 18 , characterized in that said metallic core further comprises copper (Cu) in the following mass proportion: 5%≤Cu≤40%.
20. Electrode according to claim 17 , characterized in that the metallic core of the electrode comprises at least one metal A chosen from aluminum (Al), cobalt (Co), chromium (Cr), manganese (Mn), molybdenum (Mo), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta), and hafnium (Hf) or a combination of these metals, the proportion by mass of metal A in the metallic core being as follows: 0.5%≤A≤30%.
21. Electrode according to claim 17 , characterized in that the metallic core further comprises at least one rare earth element selected from yttrium (Y), cerium (Ce), lanthanum (La) and neodymium (Nd).
22. Electrode according to claim 17 , characterized in that said layer comprising the cermet material is an intermediate layer arranged between the metallic core and a layer of oxide-rich cermet material or pure oxide.
23. Electrode according to claim 18 , characterized in that the proportions by mass of Ni and Fe in the at least one alloy of nickel (Ni) and iron (Fe) are the following:
55%≤Ni≤80%, and
20%≤Fe≤45%.
24. Method of manufacturing a cermet material comprising as mass percentages:
50% to 90% of a metallic phase which contains at least one alloy of copper (Cu) and nickel (Ni), said at least one alloy comprising as percentages by mass:
35% to 75% of nickel, and
25% to 65% of copper, and
10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of nickel: 0.2%≤Ni≤17%;
wherein the method comprises forming the cermet material using a power metallurgy method or a thermal spraying technique, characterized in that said method of manufacturing uses as raw materials comprising:
iron in metallic form or as an alloy, and optionally copper and nickel in metallic form or as an alloy, and
an oxide selected from nickel ferrite oxides Ni x Fe 3-x O 4 , NiO, Fe 2 O 3 , CuO, Cu 2 O, CuFeO 2 , the spinel of type Cu x Fe 3-x O 4 with 0<x≤1.
25. Manufacturing method according to claim 24 , characterized in that between 30% and 100% of the copper is supplied in the form of an oxide.
26. Manufacturing method according to claim 24 , characterized in that between 30% and 100% of the iron is supplied in the form of metallic iron.