Metal alloy composites

Abstract

This invention relates to metal composites and to metal-alloy composites. Metal-alloy composites of this invention comprise a metal alloy and layered inorganic nanostructures or nanoparticles such as nanotubes, nanoscrolls, spherical or quasi-spherical nanoparticles, nano-platelets or combinations thereof. Methods of producing the metal composites and the metal-alloy composites are demonstrated. The layered inorganic nanostructure serves as a strengthening phase. The layered inorganic nanostructure provides reinforcement to the metal alloy.

What is claimed is: 
     
         1 . A metal or a metal-alloy composite comprising:
 a. metal or a metal alloy; and   b. inorganic layered nanostructured material, wherein the inorganic layered nanostructured material does not comprise carbon.   
     
     
         2 . (canceled) 
     
     
         3 . The metal-alloy composite of  claim 1 , wherein said metal alloy composite comprises Mg, Fe, Cu, Al, Ti, Zn, Ni, Hg, Mn, Ag, Au or a combination thereof. 
     
     
         4 . The metal-alloy composite of  claim 3 , wherein the base metal in said metal alloy is Mg. 
     
     
         5 . The metal-alloy composite of  claim 3 , wherein the base metal in said metal alloy is Fe, Cu, Al, Ti, Zn, Ni, Hg. 
     
     
         6 . The metal-alloy composite of  claim 1 , wherein said metal alloy comprises one or more secondary metals. 
     
     
         7 . The metal-alloy composite of  claim 6 , wherein said secondary metal(s) in said metal alloy comprises Al, Zn, Mn or a combination thereof. 
     
     
         8 . The metal-alloy composite of  claim 6 , wherein said secondary metal(s) in said metal alloy comprises Zn, Al, Cu, Mg, Mn, Sn, Sb, Ag, Au, Pt, Pd, In, Zr, Ni, Fe, C, Si, Ti, Pb, Be, Y, Cc, Nd, Ca, Os, As, Ba, B, Cr, Co, Ga, Ge, Li, Rh, Ru, Se, Sr, W, Na, Pt, Cd, Bi, or a combination thereof. 
     
     
         9 . The composite of  claim 1 , wherein said layered inorganic nanostructured material is a spherical nanoparticle, a quasi-spherical nanoparticle, a nanotube, a nanoscroll, a nano-platelet or a combination thereof. 
     
     
         10 . The composite of  claim 1 , wherein said inorganic layered nanostructured material comprises WS 2 , MoS 2 , or a combination thereof. 
     
     
         11 . The metal alloy composite material of  claim 9 , wherein the sulfur-containing compound is 2H-phase WS 2 . 
     
     
         12 . The composite material of  claim 1 , wherein the concentration of said layered inorganic nanostructured material in said composite ranges between 0.001 wt % to 15 wt %. 
     
     
         13 . The composite of  claim 12 , wherein the concentration of said layered inorganic nanostructured material in said composite ranges between 0.001 wt % and 1 wt %. 
     
     
         14 . The metal-alloy composite of  claim 1 , wherein the % increase in fracture toughness of said composite with respect to an alloy without the inorganic layered structure ranges between 250% and 300%. 
     
     
         15 . The metal-alloy composite of  claim 1 , wherein the % increase in yield strength of said composite with respect to an alloy without the inorganic layered structure ranges between 15% and 20%. 
     
     
         16 . The metal-alloy composite of  claim 1 , wherein the % increase in ultimate tensile strength of said composite with respect to an alloy without the inorganic layered structure ranges between 45% and 70%. 
     
     
         17 . The metal-alloy composite of  claim 1 , wherein the elongation of said composite with respect to an alloy without the inorganic layered structure ranges between 140% and 400%. 
     
     
         18 . The metal-alloy composite of  claim 1 , wherein the size of the grains of said composite ranges between 50 μm-100 μm. 
     
     
         19 . A method for producing a metal or a metal-alloy composite comprising:
 metal or metal alloy; and   layered inorganic nanostructures;   
       wherein said method comprises:
 a. placing said metal or metal alloy and said inorganic layered nanostructured material in a crucible; 
 b. heating said metal or metal alloy and said inorganic layered nanostructured material in said crucible to a first temperature, forming a melt; 
 c. stirring said melt of said metal or metal alloy and said inorganic layered nanostructured material in said crucible; 
 d. bringing gas into contact with said melt in said crucible; 
 e. optionally heating said melt in said crucible to a second temperature; 
 f. optionally heating said melt in said crucible to a third temperature; 
 g. pouring said melt into a mold; 
 h. cooling said melt; thus forming a solid metal or metal-alloy composite. 
 
     
     
         20 . (canceled) 
     
     
         21 . The method of  claim 19 , wherein the order of steps b, c, and d is switched or wherein steps b; c, and d are conducted in parallel or at least partially overlap in time. 
     
     
         22 . The method of  claim 19 , wherein said first temperature is 380-420° C., said second temperature is 580-620° C. and said third temperature is 680-720° C. 
     
     
         23 . The method of  claim 19 , wherein said gas is selected from the group consisting of CO 2 , SF 6 , N 2 , Ar or a combination thereof. 
     
     
         24 . The method of  claim 19 , wherein said melt is kept at said first temperature and optionally at said second temperature and optionally at said third temperature for a period of time ranging between 10 min-20 min. 
     
     
         25 . The method of  claim 19 , wherein said heating is conducted in a resistance-heating furnace. 
     
     
         26 . The method of  claim 19 , wherein said stirring is conducted using a stirrer comprising a vane, a blade, a rod, a screw or a combination thereof. 
     
     
         27 . A method for producing a metal or a metal-alloy composite comprising:
 metal or metal alloy; and   layered inorganic nanostructures;   
       wherein said method comprises:
 heating a metal or a metal alloy to form a melt or a metal solution; 
 adding a layered inorganic nanostructure into the metal or metal solution; 
 cooling down the metal or metal solution containing the metal or metal alloy and the layered inorganic nanostructures to form a composite material; and 
 optionally performing a solid solution treatment to the composite material. 
 
     
     
         28 . (canceled) 
     
     
         29 . The method of  claim 27 , wherein the metal alloy is a magnesium-based alloy or an aluminum-based alloy. 
     
     
         30 . The method of  claim 27 , wherein the layered inorganic nanostructure is a sulfur-containing compound. 
     
     
         31 . The method of  claim 30 , wherein the sulfur-containing compound comprises tungsten disulfide (WS 2 ), molybdenum disulfide (MoS 2 ) or a combination thereof. 
     
     
         32 . The method of  claim 27 , further comprising introducing a protective gas when heating the metal or the metal alloy. 
     
     
         33 . The method of  claim 32 , wherein introducing the protective gas comprises introducing helium (He), argon (Ar), nitrogen (N 2 ), sulfur hexafluoride (SF 6 ), carbon dioxide (CO 2 ) or a combination thereof. 
     
     
         34 . The method of  claim 32 , wherein protective gas introduction is stopped after holding a temperature of between 600° C. and 800° C. for 1 min to 2 hour. 
     
     
         35 . A metal composite or a metal-alloy composite comprising:
 a. metal or metal alloy; and   b. inorganic layered nanostructured material.   wherein said metal composite or metal-alloy composite is produced by the method described in  claim 19 .   
     
     
         36 . A metal composite or a metal-alloy composite comprising:
 a. metal or metal alloy; and   b. inorganic layered nanostructured material.   wherein said metal composite or metal-alloy composite is produce by the method described in  claim 27 .