Thermally stabilized nickel-cobalt materials and methods of thermally stabilizing the same
Nickel-cobalt materials, methods of forming a nickel-cobalt material, and methods of thermally stabilizing a nickel-cobalt material are provided. A nickel-cobalt material may include a metal matrix composite with amorphous regions and crystalline regions substantially encompassed by a nanocrystalline grain structure with a grain size distribution of about 50 nanometers to about 800 nanometers, and the nanocrystalline grain structure may include widespread intragranular twinning. The metal matrix composite may have a chemical makeup that includes nickel, cobalt, and a dopant such as phosphorus and/or boron. A nickel-cobalt material may be heat treated within a first temperature zone below the onset temperature for grain growth and then within a second temperature zone above the onset temperature for grain growth in the material. Chemical composition and heat treatment may yield a thermally stabilized nickel-cobalt material.
1. A method of forming a nickel-cobalt material, the method comprising:
heat treating the nickel-cobalt material within a first temperature zone from about 600K to about 750K, the nickel-cobalt material comprising between 40-90% by weight nickel and between 10-60% by weight cobalt, wherein the first temperature zone is below an onset temperature for grain growth in the nickel-cobalt material.
2. The method of claim 1 , further comprising:
heat treating the nickel-cobalt material within a second temperature zone above the onset temperature for grain growth in the nickel-cobalt material, the second temperature zone being from about 800K to about 900K.
3. The method of claim 1 , wherein the nickel-cobalt material comprises a doped nickel-cobalt material, the doped nickel-cobalt material formed using an electrodeposition process.
4. The method of claim 3 , wherein the doped nickel-cobalt material comprises a dopant, the dopant comprising aluminum, antimony, arsenic, boron, beryllium, cadmium, carbon, chromium, copper, erbium, europium, gallium, germanium, gold, iron, indium, iridium, lead, magnesium, manganese, mercury, molybdenum, niobium, neodymium, palladium, phosphorus, platinum, rhenium, rhodium, selenium, silicon, sulfur, tantalum, tellurium, tin, titanium, tungsten, vanadium, zinc, and/or zirconium.
5. The method of claim 1 , wherein the nickel-cobalt material comprises a phosphorous-doped nickel-cobalt material, the phosphorous-doped nickel-cobalt material formed using an electrodeposition process.
6. The method of claim 1 , wherein the nickel-cobalt material comprises from about 100 ppm to about 20,000 ppm by weight of a dopant.
7. The method of claim 6 , wherein a concentration of the dopant in the nickel-cobalt material is from about 1,000 ppm to about 2,500 ppm by weight.
8. The method of claim 1 , wherein the nickel-cobalt material comprises from about 100 ppm to about 20,000 ppm by weight of phosphorous.
9. The method of claim 1 , further comprising:
heat treating the nickel-cobalt material within the first temperature zone for a period of from 30 minutes to 36 hours.
10. The method of claim 2 , further comprising:
heat treating the nickel-cobalt material within the second temperature zone for a period of from 10 minutes to 5 hours.
11. The method of claim 1 , wherein prior to heat treating, the nickel-cobalt material comprises a nanocrystalline grain structure having a grain size distribution of about 20 to 100 nanometers substantially encompassing the nickel-cobalt material.
12. The method of claim 1 , wherein after heat treating, the nickel-cobalt material comprises a nanocrystalline grain structure having a grain size distribution of about 20 to about 100 nanometers substantially encompassing the nickel-cobalt material.
13. The method of claim 1 , further comprising:
heat treating the nickel-cobalt material within a temperature zone above the onset temperature for grain growth in the nickel-cobalt material, providing a metal matrix composite comprising amorphous metal regions and crystalline grain regions, the crystalline grain regions having a grain size distribution of about 50 to about 800 nanometers.
14. The method of claim 13 , wherein the temperature zone above the onset temperature for grain growth in the nickel-cobalt material is from about 800K to about 900K.
15. The method of claim 14 , wherein prior to heat treating within the temperature zone below the onset temperature for grain growth, the nickel-cobalt material comprises a metal matrix composite substantially encompassing the nickel-cobalt material, the metal matrix composite having amorphous metal regions and ultra-fine nanocrystalline grain regions.
16. The method of claim 1 , wherein the first temperature zone is between 625-650 K, and wherein the nickel-cobalt material comprises 30% by weight cobalt.
17. The method of claim 1 , wherein the first temperature zone is between 650-700 K.
18. The method of claim 17 , further comprising heat treating the nickel-cobalt material within a second temperature zone above the onset temperature for grain growth in the nickel-cobalt material, wherein the second temperature zone is between 700-750 K.
19. A method of forming a nickel-cobalt material, the method comprising:
performing a heat treatment on a precursor material to determine an onset temperature for grain growth in the nickel-cobalt material; and
heat treating the nickel-cobalt material within a first temperature zone from about 600K to about 750K, wherein the first temperature zone is below the onset temperature for grain growth.
20. The method of claim 19 , wherein the heat treatment comprises an isochronal heat treatment.