Ni-free zr-based bmgs for black hue control

Abstract

The disclosure provides nickel free Zr—Cu—Al metallic glass-forming alloys and metallic glasses comprising at least of Pt, Pd, and Co where the atomic fraction of Zr ranges from 50 to 70, the atomic fraction of Cu ranges from 15 to 45, the atomic fraction of Al ranges from 5 to 15, and the combined atomic fraction of Pt, Pd, and Co ranges from 1 to 10.

What is claimed is: 
     
         1 . A metallic glass-forming alloy having a composition represented by the following formula (subscripts denote atomic percentages):
   Zr (100-a-b-c) Cu a Al b X c      where:   X is at least one of Pt, Pd, and Co   a ranges from 15 to 45 at %;   b ranges from 5 to 15 at %;   c ranges from 1 to 10 at %;   wherein the critical rod diameter of the metallic glass-forming alloy is at least 1 mm, and   wherein a thermal stability of the supercooled liquid of the composition is at least 70 K.   
     
     
         2 . The metallic glass-forming alloy of  claim 1  wherein the atomic fraction of Zr ranges from 55 to 65 at %. 
     
     
         3 . The metallic glass-forming alloy of  claim 1  wherein the atomic fraction of Cu ranges from 15 to 40 at %. 
     
     
         4 . The metallic glass-forming alloy of  claim 1  wherein b is 8 to 12 at %. 
     
     
         5 . The metallic glass-forming alloy of  claim 1  wherein a is from 18 to 38, b is from 8 to 12, and c is from 2 to 7. 
     
     
         6 . The metallic glass-forming alloy of  claim 1  wherein X is Pt. 
     
     
         7 . The metallic glass-forming alloy of  claim 6  wherein a is from 18 to 31, b is from 8 to 12, and c is from 2 to 7. 
     
     
         8 . The metallic glass-forming alloy of  claim 7  wherein the alloy has a brightness L*from 35 to 50, an a* value from −0.1 to 1, and a b* value from −0.25 to +5. 
     
     
         9 . The metallic glass-forming alloy of  claim 1  wherein X is Pd or Pt. 
     
     
         10 . The metallic glass-forming alloy of  claim 9  wherein a ranges from 18 to 35, b is from 8 to 12, and c ranges from 2 to 7. 
     
     
         11 . The metallic glass-forming alloy of  claim 10  wherein the alloy has a brightness L* from 36 to 444, an a* value from −0.5 to 0.5, and a b* value from −5.25 to 1. 
     
     
         12 . The metallic glass-forming alloy of  claim 8  wherein a is from 18 to 38, b is from 8 to 12, and c is from 2 to 7. 
     
     
         13 . The metallic glass-forming alloy of  claim 13  wherein the alloy has a brightness L* from 35 to 45, an a* value from −0.3 to 0.25, and a b* value from −4.5 to 6. 
     
     
         14 . A metallic glass comprising an alloy where a composition of the alloy is represented by the following formula (subscripts denote atomic percentages):
   Zr (100-a-b-c) Cu a Al b X c      where:   a ranges from 15 to 45;   b ranges from 5 to 15;   c ranges from 1 to 10;   where X can is selected from at least one of Pd, Pt, Co, and a combinations thereof.   
     
     
         15 . The metallic glass of  claim 14  wherein a ranges from 15 to 40. 
     
     
         16 . The metallic glass of  claim 14  wherein a ranges from 18 to 38, b is 10, and c ranges from 2 to 7. 
     
     
         17 . A method of producing the metallic glass comprising:
 melting an alloy into a molten state; where the alloy has a composition represented by the following formula (subscripts denote atomic percentages):
   Zr (100-a-b-c) Cu a Al b X c    
   where:   a ranges from 15 to 45;   b ranges from 5 to 15;   c ranges from 1 to 10;
 where X can is selected from at least one of Pd, Pt, Co, and a combinations thereof; and 
   quenching the melt at a cooling rate sufficiently rapid to prevent crystallization of the alloy.   
     
     
         18 . The method of  claim 17  wherein the atomic fraction of Cu ranges from 15 to 40 at %. 
     
     
         19 . The method of  claim 17 , further comprising fluxing the melt with a reducing agent prior to quenching. 
     
     
         20 . The method of  claim 17  wherein the temperature of the melt prior to quenching is at least 1100° C.