3d printable hard ferrous metallic alloys for powder bed fusion

Abstract

Alloy compositions for 3D metal printing procedures which provide metallic parts with high hardness, tensile strengths, yield strengths, and elongation. The alloys include Fe, Cr and Mo and at least three or more elements selected from C, Ni, Cu, Nb, Si and N. As built parts indicate a tensile strength of at least 1000 MPa, yield strength of at least 640 MPa, elongation of at least 3.0% and hardness (HV) of at least 375.

What is claimed is: 
     
         1 . An alloy for 3D printing of a metallic part, the alloy comprising:
 C is present at 0.1 to 0.35 wt. %, based on the total weight of the alloy,   Cr is present at 10.0 wt. % to 19.0 wt. %, based on the total weight of the alloy,   Mo is present at 0.5 wt. % to 3.0 wt. %, based on the total weight of the alloy; and   at least two elements from the group consisting of Ni, Cu, Nb, Si and,
 wherein if present Ni is present at 0 to 5.0 wt. %, based on the total weight of the alloy, 
 wherein if present Cu is present at 0 to 5.0 wt. %, based on the total weight of the alloy, 
 wherein if present Nb is present at 0 to 1.0 wt. %, based on the total weight of the alloy, 
 wherein if present Si is present at 0 to 1.0 wt. %, based on the total weight of the alloy, and 
 wherein if present N is present at 0 to 0.25 wt. %, based on the total weight of the alloy; and 
   the balance of the alloy composition containing Fe.   
     
     
         2 . The alloy of  claim 1 , wherein Cr is present at 10.0 wt. % to 18.3 wt. %, C is present at 0.1 to 0.30 wt. %, Mo is present at 0.5 wt. % to 2.5 wt. %, Ni is present at 0 to 4.0 wt. %, Cu is present at 0 to 4.0 wt. %, Nb is present at 0 to 0.7 wt. %, Si is present at 0 to 0.7 wt. % and N is present at 0 to 0.25 wt. %. 
     
     
         3 . The method of  claim 1 , wherein Cr is present at 10.5 wt. % to 19.0 wt. %. 
     
     
         4 . The alloy of  claim 1 , wherein Mo is present at 0.89 wt. % to 3.0 wt. %. 
     
     
         5 . The alloy of  claim 1 , wherein C is present at 0.1 wt. % to 0.25 wt. %. 
     
     
         6 . The alloy of  claim 1 , wherein the alloy includes at least three elements selected from the group consisting of Ni, Cu, Nb, Si and N. 
     
     
         7 . The alloy of  claim 1 , wherein the alloy includes at least four elements selected from the group consisting of Ni, Cu, Nb, Si and N. 
     
     
         8 . The alloy of  claim 1 , wherein the alloy includes Ni, Cu, Nb, Si and N. 
     
     
         9 . The alloy of  claim 1 , wherein the alloy, when printed, is capable of forming a metallic part having the following properties: tensile strength of at least 1000 MPa, yield strength of at least 640 MPa, elongation of at least 1.0%, hardness (HV) of at least 375. 
     
     
         10 . The alloy of  claim 1 , wherein the alloy, when printed, is capable of forming a metallic part having the following properties: a tensile strength of 1000 MPa to 1900 MPa, a yield strength of 640 MPa to 1500 MPa, an elongation of 1.0% to 25.0%, and a hardness (HV) of 375 to 600. 
     
     
         11 . The alloy of  claim 1 , wherein the alloy, when printed, is capable of forming a metallic part having the following properties: a tensile strength of at least 1000 MPa, a yield strength of at least 900 MPa, an elongation of at least 1.0% and a hardness (HV) of at least 475. 
     
     
         12 . The alloy of  claim 1 , wherein the alloy is in a powder form. 
     
     
         13 . The alloy of  claim 12 , wherein the powder form has >10% wt. particles with a diameter in the range of 1 to 200 microns. 
     
     
         14 . The alloy of  claim 12 , wherein the powder form has >5% wt. particles with a diameter in the range of 3 to 70 microns. 
     
     
         15 . The alloy of  claim 12 , wherein the powder form has >5% wt. particles with a diameter in the range of 15 to 53 microns. 
     
     
         16 . A method of producing a metal alloy, the method comprising:
 supplying an alloy comprising:
 C at 0.1 to 0.35 wt. %, based on the total weight of the alloy, 
 Cr at 10.0 wt. % to 19.0 wt. %, based on the total weight of the alloy, 
 Mo at 0.5 wt. % to 3.0 wt. %, based on the total weight of the alloy; and 
 at least two elements from the group consisting of Ni, Cu, Nb, Si and, 
 wherein if present Ni is present at 0 to 5.0 wt. %, based on the total weight of the alloy, 
 wherein if present Cu is present at 0 to 5.0 wt. %, based on the total weight of the alloy, 
 wherein if present Nb is present at 0 to 1.0 wt. %, based on the total weight of the alloy, 
 wherein if present Si is present at 0 to 1.0 wt. %, based on the total weight of the alloy, and 
 wherein if present N is present at 0 to 0.25 wt. %, based on the total weight of the alloy; and 
 the balance of the alloy composition containing Fe; 
   melting the alloy;   atomizing the melted alloy to form a powder metal alloy.   
     
     
         17 . The method of  claim 16 , wherein the atomization comprises at least one of gas atomization, water atomization or centrifugal atomization. 
     
     
         18 . The method of  claim 16 , further comprising 3D printing the powder metal alloy to form a metallic part by at least in part by a solid-liquid-solid phase transformation. 
     
     
         19 . The method of  claim 18 , wherein the solid-liquid-solid phase transformation comprises at least in part powder bed fusion (PBF). 
     
     
         20 . The method of  claim 16 , wherein the powder metal alloy has >10% wt. particles with a diameter in the range of 1 to 200 microns.