Methods of making gold-titanium alloys from sintered powders

Abstract

A method of making a gold-titanium alloy can include preparing a powder mixture of gold source powder and titanium source powder. The method can also include consolidating the powder mixture to form a consolidated body. The consolidated body can be at least partially sintered in vacuum or a reducing atmosphere to for a gold-titanium alloy sintered article.Another example method of producing a gold-titanium alloy can include preparing a composite metal powder having composite granules including a gold source powder and a titanium source powder within the composite granules. The composite metal powder can be consolidated to form a consolidated body. The consolidated body can be at least partially sintered to form a sintered article. The method can also include deoxygenating at least one of the composite metal powder, the consolidated body, or the sintered article at a deoxygenation temperature under a hydrogen-containing atmosphere to reduce an oxygen content.

What is claimed is: 
     
         1 . A method of making a gold-titanium alloy, comprising;
 preparing a powder mixture comprising a gold source powder and a titanium source powder;   consolidating the powder mixture to form a consolidated body; and   at least partially sintering the consolidated body in vacuum or a reducing atmosphere to form a gold-titanium alloy sintered article.   
     
     
         2 . The method of  claim 1 , wherein a weight ratio of the gold source powder to the titanium source powder is from 1:5 to 5:1. 
     
     
         3 . The method of  claim 1 , wherein the powder mixture further contains another alloying element in an amount less than 10 wt % with respect to a total weight of the powder mixture. 
     
     
         4 . The method of  claim 3 , wherein the alloying element comprises Ag, Al, V, Fe, Co, Ba, Y, Zr, Ir, Ta, W, Ir, Ru, Re, Nb, Pd, Pt, Ni, Rh, Cr, C, Mn, Cu, Zn, B, Si, Ge, Sn, Sb, In, Mo, or a combination thereof. 
     
     
         5 . The method of  claim 1 , further comprising deoxygenating at least one of the titanium source powder, the powder mixture, and the sintered article to reduce oxygen. 
     
     
         6 . The method of  claim 5 , wherein the deoxygenating includes heating in presence of a magnesium deoxygenation agent under a hydrogen gas atmosphere. 
     
     
         7 . The method of  claim 1 , wherein the powder mixture comprises angular particles or spherical particles. 
     
     
         8 . The method of  claim 1 , wherein the powder mixture is a pre-alloy powder, and wherein the method further comprises forming the pre-alloy powder by blending the gold source powder with the titanium source powder and granulating the blended source powders to form granules. 
     
     
         9 . The method of  claim 8 , wherein the granulating is performed by forming a slurry of the blended source powders and drying the slurry using a spray drier. 
     
     
         10 . The method of  claim 8 , wherein forming the pre-alloy powder further comprises at least partially sintering the granules. 
     
     
         11 . The method of  claim 1 , wherein the sintering is performed at a sintering temperature from 800° C. to 1400° C. 
     
     
         12 . The method of  claim 1 , wherein the powder mixture has a particle size ranging from a D10 of 1 μm to a D90 of 150 μm. 
     
     
         13 . The method of  claim 1 , wherein the titanium source powder is commercially pure (CP) titanium. 
     
     
         14 . The method of  claim 1 , further comprising performing post-processing steps to meet final part specifications. 
     
     
         15 . The method of  claim 1 , further comprising densifying the sintered article or the consolidated body to increase a density of the sintered article. 
     
     
         16 . The method of  claim 15 , wherein the consolidated body is densified by uniaxial pressing, hot pressing, cold isostatic pressing, metal injection molding, powder injection molding, centrifugal casting, slip casting, powder extrusion, gravity casting, rolling, iso-static molding, explosive compacting, or a combination thereof. 
     
     
         17 . The method of  claim 1 , wherein the consolidating comprises debinding. 
     
     
         18 . The method of  claim 1 , wherein the consolidating includes additive printing of the consolidated body using laser powder bed fusion or binder jet printing. 
     
     
         19 . The method of  claim 1 , wherein the sintered article has a grain size range where no more than 10% of grain cross-section diameters (measured in any direction) are smaller than 10 μm or larger than 100 μm. 
     
     
         20 . A method of producing a gold-titanium alloy, comprising:
 preparing a composite metal powder having composite granules including a gold source powder and a titanium source powder within the composite granules;   consolidating the composite metal powder to form a consolidated body;   at least partially sintering the consolidated body to form a sintered article; and   deoxygenating at least one of the composite metal powder, the consolidated body, or the sintered article at a deoxygenation temperature under a hydrogen-containing atmosphere to reduce an oxygen content.   
     
     
         21 . A composite metal powder comprising granules including a gold source powder and a titanium source powder, wherein a weight ratio of gold source powder to titanium source powder in the granules is from 1:5 to 5:1, and wherein a variation of the weight ratio among the granules is less than 10%. 
     
     
         22 . The composite metal powder of  claim 21 , wherein the granules are individually at least partially sintered. 
     
     
         23 . The composite metal powder of  claim 21 , wherein the granules are angular or spherical. 
     
     
         24 . The composite metal powder of  claim 21 , wherein the granules have a particle size ranging from a D10 of 1 μm to a D90 of 150 μm and wherein a variation of the particle size among the granules is less than 10%.