Additive manufacturing of iron-based amorphous metal alloys

Abstract

Embodiments disclosed herein relate to the production of amorphous metals having compositions of iron, chromium, molybdenum, carbon and boron for usage in additive manufacturing, such as in layer-by-layer deposition to produce multi-functional parts. Such parts demonstrate ultra-high strength without sacrificing toughness and also maintain the amorphous structure of the materials during and after manufacturing processes. Two additive manufacturing techniques are provided: (1) the complete melting of amorphous powder and re-solidifying to amorphous structure to eliminate the formation of crystalline structure therein by controlling a heating source power and cooling rate without affecting previous deposited layers; and (2) partial melting of the outer surface of the amorphous powder, and solidifying powder particles with each-other without undergoing a complete melting stage. Amorphous alloy compositions have oxygen impurities in low concentration levels to optimize glass forming ability (GFA). Specific techniques of additive manufacturing include those based on lasers, electron beams and ultrasonic sources.

What is claimed is: 
     
         1 . A composition comprising a feedstock comprising an amorphous alloy composition comprising iron, chromium, molybdenum, carbon and boron, wherein a level of oxygen in the feedstock is up to 0.2 at. % oxygen. 
     
     
         2 . The composition of  claim 1 , wherein the amorphous alloy composition has a formula of Fe100-(a+b+c+d)CraMobCcBd, wherein a, b, c and d represent an atomic percentage. 
     
     
         3 . The composition of  claim 1 , wherein: a is in the range of 10 at. % to 35 at. %; b is in the range of 10 at. % to 20 at. %; c is in the range of 2 at. % to 5 at. %; and d is in the balance of 0.5% at. % to 3.5 at. %. 
     
     
         4 . The composition of  claim 1 , wherein the feedstock containing the amorphous alloy composition and having up to 0.2 at. % oxygen has a glass-forming ability higher than that of a comparable feedstock having a comparable amorphous alloy composition having a same composition as that of the amorphous alloy composition and the level of the oxygen greater than 0.2 at. % oxygen. 
     
     
         5 . The composition of  claim 4 , wherein the glass forming ability is a property to generate a layer of an amorphous material when the feedstock or the comparable feedstock is exposed to wear, load or friction. 
     
     
         6 . The composition of  claim 1 , wherein the amorphous alloy composition is in a powder form. 
     
     
         7 . The composition of  claim 6 , wherein the powder has a sphericity of more than 80%. 
     
     
         8 . The composition of  claim 6 , wherein the powder has a flowability of less than 20 seconds per 50 grams. 
     
     
         9 . The composition of  claim 6 , wherein the powder has a particle size larger than 10 micrometers. 
     
     
         10 . The composition of  claim 9 , wherein the powder has the particle size is greater than 10 micrometers and less than 60 micrometers. 
     
     
         11 . The composition of  claim 6 , wherein the powder has a packing density about 30%. 
     
     
         12 . The composition of  claim 1 , wherein the feedstock is in a wire form. 
     
     
         13 . The composition of  claim 1 , wherein the feedstock is in powder form. 
     
     
         14 . The composition of  claim 1 , wherein the feedstock is in a foil form. 
     
     
         15 . The composition of  claim 2 , wherein the amorphous alloy composition has an endothermic peak between 550° C. and 750° C. in a DSC graph. 
     
     
         16 . The composition of  claim 1 , wherein the amorphous alloy composition is not fully amorphous. 
     
     
         17 . The composition of  claim 1 , wherein the feedstock has equal or less than 0.15 at. % oxygen. 
     
     
         18 . A composition comprising an amorphous alloy composition having a formula Fe(100−a+b+c+d)(CraXbYcZd), wherein the Y component is selected from the group consisting of boron, carbon and combinations thereof, while the X and Z components is selected from the group consisting of molybdenum, copper, cobalt, aluminum, titanium, tungsten, niobium, silicon, vanadium, and combinations thereof; wherein a, b, c and d represent an atomic percentage, wherein an oxygen level of the composition is up to 0.2 at. % oxygen. 
     
     
         19 . The composition of  claim 18 , wherein the amorphous alloy composition has: ‘a’ in the range of 10 at. % to 50 at. %; ‘b’ in the range of 10 at. % to 30 at %; ‘c’ in the range of 2 at. % to 10 at %, and ‘d’ in the range of 0.5 at. % to 10 at %. 
     
     
         20 . The composition of  claim 18 , wherein the composition having up to 0.2 at % oxygen and the amorphous alloy composition has a glass-forming ability that is higher than that of a comparable composition having a comparable amorphous alloy composition having a same composition as that of the amorphous alloy composition and greater than 0.2 at % oxygen; wherein the glass forming ability is a property to generate a layer of an amorphous material when the composition or the comparable composition is exposed to wear, load or friction.