Method of forming ductile metallic glasses in ribbon form
View Patent ↗The present disclosure relates to an iron based alloy composition that may include iron present in the range of 45 to 70 atomic percent, nickel present in the range of 10 to 30 atomic percent, cobalt present in the range of 0 to 15 atomic percent, boron present in the range of 7 to 25 atomic percent, carbon present in the range of 0 to 6 atomic percent, and silicon present in the range of 0 to 2 atomic percent, wherein the alloy composition exhibits an elastic strain of greater than 0.5% and a tensile strength of greater than 1 GPa.
1. A method of forming an iron based alloy composition, comprising:
melting one or more feedstocks consisting essentially of iron present in the range of 45 to 70 atomic percent; nickel present in the range of 10 to 30 atomic percent; cobalt present in the range of 0 to 15 atomic percent; boron present in the range of 7 to 25 atomic percent; carbon present in the range of 0 to 6 atomic percent; and silicon present in the range of 0 to 2 atomic percent together to form an alloy;
forming ribbon from said alloy wherein said ribbon exhibits an elastic strain of greater than 0.5% and a tensile strength of greater than 1 GPa and said ribbon consists of metallic glass and crystalline phases wherein said crystalline phases are 1 nm to 500 nm.
2. The method of claim 1 , wherein said composition consists essentially of:
iron present in the range of 46 to 69 atomic percent;
nickel present in the range of 12 to 17 atomic percent;
cobalt present in the range of 2 to 15 atomic percent;
boron present in the range of 12 to 16 atomic percent;
carbon present in the range of 4 to 5 atomic percent; and
silicon present in the range of 0.4 to 0.5 atomic percent.
3. The method of claim 1 , wherein said ribbon are cast by melt spinning.
4. The method of claim 1 , wherein said ribbon have a thickness in the range of 0. 02 to 0.15 mm.
5. The method of claim 1 , wherein said alloy has a critical cooling rate of less than 100,000K/s.
6. The method of claim 1 , wherein said ribbon exhibit an elastic strain of 0.5% to 4.0% and a tensile strength of greater than 1 GPa to 5.0 GPa.
7. The method of claim 1 , wherein said ribbon exhibits a glass to crystalline transition onset temperature in the range of 415 C to 474 C and a primary peak glass to crystalline transition temperature in the range of 425 C to 479 C, measured by DSC at a rate of 10° C. per minute.
8. The method of claim 1 , wherein said ribbon exhibits melting temperatures in the range of 1060° C. to 1120° C., measured by DSC at a rate of 10° C. per minute.
9. The method of claim 1 , wherein said ribbon includes amorphous fractions including structures that exhibit a mean grain size of less than 50 nm.
10. The method of claim 1 , wherein said ribbon includes nanocrystalline structures exhibiting a mean grain size of below 100 nm.
11. The method of claim 1 , wherein said ribbon includes microcrystalline structures exhibiting a mean grain size in the range of 100 nm to 500 nm.