Glassy nano-materials
View Patent ↗The present invention is directed at metal alloys that are capable of forming spinodal glass matrix microconstituent structure. The alloys are iron based and include nickel, boron, silicon and optionally chromium. The alloys exhibit ductility and relatively high tensile strengths and may be in the form of sheet, ribbon, wire, and/or fiber. Applications for such alloys are described.
1. A method for forming a metallic alloy containing spinodal glass matrix microconstituent (SGMM) comprising:
supplying a metallic alloy comprising Fe at a level of 45.0 atomic percent to 71 atomic percent; Ni at a level of 4.0 atomic percent to 9.0 atomic percent; B at a level of 11.0 atomic percent to 16 atomic percent; Si at a level of 0.3 atomic percent to 4.0 atomic percent, chromium at a level of 12 at % to 19 at % and does not include cobalt;
melting said alloy; and
forming said spinodal glass matrix microconstituent through spinodal decomposition of said metallic alloy wherein said metallic alloy upon cooling separates into two distinct phases that are different in chemical composition and physical properties, wherein said phase formation is not nucleation controlled and said SGMM structure includes one or more semicrystalline or crystalline phases wherein the semicrystalline phase comprises clusters exhibiting a largest linear dimension of 2.0 nm or less and said crystalline phase comprises clusters exhibiting a largest linear dimension of greater than 2.0 nm and a glass matrix where the structural units in said glass matrix have a size of 5 Å to 100 Å;
wherein said alloy containing said SGMM structure has an ultimate tensile strength in the range of 0.4 GPa to 3.9 GPa and tensile elongation in the range of 0.4% to 5.5%.
2. The method of claim 1 wherein said SGGM structure is present in said alloy at a level of 5.0% to 95% by volume.
3. The method of claim 1 wherein said alloy exhibits a glass to crystalline transformation in the temperature range of 396° C. to 713° C.
4. The method of claim 1 wherein said alloy exhibits a Vickers Hardness in the range of 900 to 950.
5. The method of claim 1 wherein said alloy has a thickness of greater than 1.0 micron.
6. The method of claim 1 wherein said cooling comprises any one of melt-spinning, jet casting, hyperquenching, wire casting, planar flow casting or twin-roll casting.
7. The method of claim 1 wherein said alloy containing said SGMM structure has a thickness in the range of 0.5 mm to 5.0 mm.
8. The method of claim 1 wherein said alloy containing said SGGM structure is in the form of wire or fiber, having a diameter in the range of 1 μm to 120 μm.