Antimicrobial niobium alloy

Abstract

An antimicrobial alloy includes titanium, niobium, and silver. Further, the antimicrobial alloy includes between 5 and 30 atomic percent niobium, up to 3 atomic percent silver, the remaining atomic percentage is titanium, and the alloy does not include zirconium. The antimicrobial alloy has a predominantly beta-titanium crystal structure and an elasticity modulus ranging from 60 to 85 GPa. A process for manufacturing the antimicrobial alloy. The antimicrobial alloy prepared by the method can be used in bioimplants.

1 . An antimicrobial alloy, comprising:
 titanium, niobium, and silver; wherein the alloy comprises between 10 and 30 atomic percent niobium, up to 3 atomic percent silver and between 67 and 7 atomic percent titanium, wherein atomic percent is calculated based on the total number of Ti, Nb and Ag atoms;   wherein the alloy does not comprise zirconium; and   wherein the antimicrobial alloy has at least 51 percent beta-titanium crystal structure, determined by scanning electron microscope image analysis, and an elasticity modulus ranging from 60 to 85 GPa as measured according to ASTM E111,   wherein the alloy has a bulk densification percentage, given by the following expression;   (ρ ex  of uniaxially pressed powder mixture)/(ρ ex  of sintered alloy)×100 that ranges from 80.0 to 95.0%, wherein ρ ex  is calculated according to the equation   
       
         
           
             
               
                 ρ 
                 ex 
               
               = 
               
                 
                   
                     ( 
                     
                       a 
                       / 
                       
                         ( 
                         
                           a 
                           - 
                           b 
                         
                         ) 
                       
                     
                     ) 
                   
                   * 
                   
                     ( 
                     
                       
                         ρ 
                         L 
                       
                       - 
                       
                         ρ 
                         a 
                       
                     
                     ) 
                   
                 
                 + 
                 
                   ρ 
                   a 
                 
               
             
           
         
         wherein ρ ex  is the measured density of the specimen as measured by a densimeter, ‘a’ and ‘b’ are the weight of the specimen in air and water, respectively, and ‘ρ L ’ and ‘ρ a ’ are the density of water and air, respectively. 
       
     
     
         2 . (canceled) 
     
     
         3 . The antimicrobial alloy of  claim 1  wherein the bulk densification percentage ranges from 89.3 to 89.7%. 
     
     
         4 . (canceled) 
     
     
         5 . The antimicrobial alloy of  claim 1  wherein the alloy has a microhardness ranging from 2.692 to 2.742 GP according to ASTM E384. 
     
     
         6 . The antimicrobial alloy of  claim 1  wherein the alloy has an elasticity modulus of about 80 GPa as measured according to ASTM E111. 
     
     
         7 . The antimicrobial alloy of  claim 1  wherein the alloy has a corrosion potential voltage ranging from −0.130 and −0.150 V as measured using electrochemical impedance spectroscopy in at least one of the group consisting of artificial saliva and simulated body fluid. 
     
     
         8 . (canceled) 
     
     
         9 . The antimicrobial alloy of  claim 1  wherein said alloy inhibits gram-positive bacteria growth by at least 85 percent as measured by agar diffusion according to the equation 
       
         
           
             
               
                 Inhibition 
                 ⁢ 
                      
                 efficiency 
                 ⁢ 
                      
                 rates 
                 ⁢ 
                     
                 
                   ( 
                   % 
                   ) 
                 
               
               = 
               
                 
                   ( 
                   
                     
                       N 
                       ⁢ 
                       0 
                     
                     - 
                     N 
                   
                   ) 
                 
                 / 
                 N 
                 ⁢ 
                 0 
                 × 
                 100 
               
             
           
         
         wherein N0 and N represent the average number of colony forming units in control and said alloy-treated samples, respectively. 
       
     
     
         10 - 16 . (canceled)