Sintered nanocrystallinealloys

Abstract

Provided in one embodiment is a method, comprising: sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy, wherein at least some of the nanocrystalline particulates may include a non-equilibrium phase comprising a first metal material and a second metal material, and the first metal material may be soluble in the second metal material. The sintered nanocrystalline alloy may comprise a bulk nanocrystalline alloy.

1 . A method comprising:
 sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy; wherein
 at least some of the nanocrystalline particulates comprise a non-equilibrium phase comprising a first metal material and a second metal material; and 
 the first metal material is soluble in the second metal material. 
   
     
     
         2 . The method of  claim 1 , wherein the first metal material comprises at least one of tungsten and chromium. 
     
     
         3 . The method of  claim 1 , wherein the second metal material comprises at least one of Pd, Pt, Ni, Co, Fe, Ti, V, Cr, and Sc. 
     
     
         4 . The method of  claim 1 , wherein the non-equilibrium phase comprises a solid solution. 
     
     
         5 . The method of  claim 1 , further comprising forming the at least some of the nanocrystalline particulates by mechanically working a powder comprising the first metal material and the second metal material. 
     
     
         6 . The method of  claim 1 , further comprising forming the at least some of the nanocrystalline particulates by ball milling a powder comprising the first metal material and the second metal material. 
     
     
         7 . The method of  claim 1 , wherein the at least some of the nanocrystalline particulates have a grain size of smaller than or equal to about 50 nm. 
     
     
         8 . The method of  claim 1 , wherein the non-equilibrium phase undergoes decomposition during the sintering. 
     
     
         9 . The method of  claim 1 , wherein the non-equilibrium phase undergoes decomposition during the sintering, and the decomposition of the non-equilibrium phase accelerates a rate of sintering of the nanocrystalline particulates. 
     
     
         10 . The method of  claim 1 , wherein the at least some of the nanocrystalline particulates comprise less than or equal to about 40 at % of the second metal material. 
     
     
         11 . The method of  claim 1 , wherein the non-equilibrium phase comprises a supersaturated phase comprising the second metal material dissolved in the first metal material. 
     
     
         12 . The method of  claim 1 , further comprising alloying the nanocrystalline alloy with a third metal material. 
     
     
         13 . The method of  claim 1 , wherein the nanocrystalline alloy has a first grain size, and a sintered material comprising the first metal material in the absence of the second metal material has a second grain size, the first grain size being smaller than the second grain size. 
     
     
         14 . The method of  claim 1 , wherein the nanocrystalline alloy has a relative density of at least about 90%. 
     
     
         15 . The method of  claim 1 , wherein the first metal material comprises Cr and the second metal material comprises Ni. 
     
     
         16 . A method comprising:
 sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy; wherein   at least some of the nanocrystalline particulates comprise a non-equilibrium phase comprising a first metal material and a second metal material; and   the sintering involves a first sintering temperature, and the first sintering temperature is lower than a second sintering temperature needed for sintering the first metal material in the absence of the second metal material.   
     
     
         17 . The method of  claim 16 , wherein the first sintering temperature is lower than or equal to about 1200° C. 
     
     
         18 . The method of  claim 16 , wherein
 the sintering further comprises forming a second phase at at least one of a surface and a grain boundary of the nanocrystalline particulates during the sintering; and   the first metal material is soluble in the second phase.   
     
     
         19 . The method of  claim 16 , wherein
 the sintering further comprises forming a second phase at at least one of a surface and a grain boundary of the nanocrystalline particulates during the sintering; and   the second phase is rich in the second metal material.   
     
     
         20 . The method of  claim 16 , wherein during the sintering, the first metal material has a first diffusivity in itself and a second diffusivity in a second phase rich in the second metal material, the first diffusivity being smaller than the second diffusivity. 
     
     
         21 . The method of  claim 16 , wherein the nanocrystalline alloy has a first grain size and a sintered material comprising the first metal material in the absence of the second metal material has a second grain size, the first grain size being smaller than the second grain size. 
     
     
         22 . A method comprising:
 sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy; wherein   at least some of the nanocrystalline particulates comprise a non-equilibrium phase comprising a first metal material and a second metal material;   the first metal material is soluble in the second metal material; and   the nanocrystalline alloy has a relative density of at least about 90%.