Patent Publication Number: US-2018044770-A1

Title: (ZrM)-(CuN)-Ni-Al-RE amorphous alloy and manufacturing method and application thereof

Description:
FIELD OF INVENTION 
     The present invention relates to a Zr-based amorphous alloy preparation technology, and more particularly to a (ZrM)-(CuN)—Ni—Al-RE amorphous alloy having a high glass froming ability and preparation and application thereof. 
     DESCRIPTION OF RELATED ARTS 
     Zr-based amorphous alloys have many excellent properties due to their structural specificities, such as high strength (1500-2000 MPa), high hardness (about HRC 50), high elasticity limit (about 2%), excellent corrosion resistance and liquid near-net formability, etc., they have important application prospects in the fields of consumer electronics, medical and health, aerospace and transportation and other fields. 
     For the Zr-based amorphous alloy, a variety of alloy compositions have been developed, such as the Zr—Ti—Cu—Ni—Be system alloy developed in the United States, having a critical cooling rate of 1K/s, and with a strong glass froming ability and a high manufacturability. However, the application range of the alloy system is limited by its toxicBe element. Zr—Ti—Cu—Ni—Al and Zr—Nb—Cu—Ni—Al amorphous alloy have an amorphous size of φ15 mm and a relatively weak glass froming ability. Japan developed a Zr—Al—Ni—Cu alloy system, has an amorphous size of φ30 mm. However, the alloy system requires more strict preparation conditions, high-purity raw materials and high vacuum preparation technology, which restrict its application. 
     In order to improve the glass froming ability of the Zr-based amorphous alloy, a large amount of research work has been done by adjusting the compositions of the Zr—Cu—Ni—Al alloy and adding alloying elements, which mainly focused on the forming ability of the Zr—Cu—Ni—Al amorphous alloy itself. Ag, Ti, Fe, Hf and rare earth RE elements are added separately to the Zr—Cu—Ni—Al alloy, or Ag and Re are added simultaneously, but the principle of addition is not clearly stated (or is not clear), so that the added element and its content is not targeted, and the amorphous manufacturability of the alloy is not significantly improved or unknown. 
     The manufacturability (ie, the manufacturability of the amorphous alloy by employing industrial grade raw materials, low vacuum preparation and multiple cyclic utilization) of the Zr—Cu—Ni—Al alloy in the application process determines its application feasibility. Aiming at this, the present invention has developed a (ZrM)-(CuN)—Ni—Al-(RE) amorphous alloy having excellent glass froming ability and manufacturability, excellent mechanical properties and more excellent antibacterial and bacteriostatic function, have broad application prospects in the consumer electronics, health care, transportation and other fields. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention provides a Zr—Cu—Ni—Al alloy having the composition of M, N and RE elements, wherein the (ZrM)-(CuN)—Ni—Al-(RE) alloy has a high glass froming ability and manufacturability, excellent mechanical properties and antibacterial and bacteriostatic functions, which laid the application foundation of the alloy. 
     The conventional Zr—Cu—Ni—Al amorphous alloy has excellent mechanical properties and forming ability, but its manufacturing ability is relatively poor, that is, in the practical application of the preparation process, the forming, defect control, production efficiency and cost and other factors have to be considered together: the purity of raw materials and the preparation vacuum are relatively low, which result in its decreased glass froming ability, decreased manufacturability and limited practical application. 
     The present invention comprehensively considers the glass froming ability and manufacturability of Zr—Cu—Ni—Al type amorphous alloy, and aims to solve the bottleneck problem that restricts its application. It is found that the Zr—Cu—Ni—Al alloy can easily precipitate CuZr compound during the solidification process. If the precipitation of CuZr compound is effectively inhibited, the manufacturability of Zr—Cu—Ni—Al can be improved. 
     In the present invention, a small amount of Cu-like and Zr-like and rare earth RE elements are added: Cu-like element: N (Ag), Zr-like element M (Hf, Ti), so during the precipitate process, Cu and N elements compete with each other to form the compounds (CuZr and AgCu compounds) with Zr element, and Zr and M (Hf, Ti) elements compete with each other to form the compounds (such as CuZr, CuHf). The result of competing with each other is that the solidification process is complicated, the precipitation of CuZr is inhibited, and the glass froming ability and manufacturability of Zr—Cu—Ni—Al are improved. 
     The addition of rare earth element RE can effectively reduce the effect of the increase of the oxygen content on the glass froming ability due to the low degree of vacuum. On the one hand, the rare earth element RE is combined with oxygen to form oxide, floating on its surface, thus inhibiting the combination of oxygen and other elements, on the other hand, the addition of RE increases the complexity of alloying elements, to enhance the glass froming ability thereof. The simultaneous addition of M, N and RE in the Zr—Cu—Ni—Al alloy significantly increases the forming ability and manufacturability of the alloy. Adding separately M, N or RE have a certain role, but simultaneously adding these elements will generate a best result. 
     The technical solution of the present invention is as follows: 
     A (ZrM)-(CuN)—Ni—Al-RE amorphous alloy for manufacturing a mechanical component, which containing: 
     40-65% of Zr, 18-46% of Cu, 2-15% of Ni, 4-15% of Al, 0.1-3% of M, 0.05-3% of N, 0.1-2% of a rare earth element RE, wherein M is Hf and/or Ti, and N is Ag, the rare earth element RE is Y, Gd, Er, Sc or a combination thereof. 
     The preferably composition ratio: Zr: 50˜55%, Cu: 28˜35%, Ni: 4˜7%, Al: 5˜11%, M: 0.1˜1.0%, N: 0.05˜1.0%, rare earth element RE: 0.1˜1.0%. 
     The present invention is characterized in that a small amount of M, N and RE elements are simultaneously added into the basis alloy of Zr—Cu—Ni—Al. In practical applications, the factors such as cost, mechanical properties and surface quality of samples are taken into account. The atomic percentages of Hf, Ag and RE elements are controlled at 1%, and the atomic percentage of Ti is controlled at ≦2%. 
     The method for preparing (ZrM)-(CuN)—Ni—Al-RE amorphous alloy according to the present invention, is characterized in that, preparing a mother alloy ingot by an arc melting process or an induction melting process, by using Zr, Cu, Ni, Al, M, N and RE as raw materials; heating the mother alloy ingot by arc heating or induction heating process; and then preparing the amorphous alloy by casting or die casting process, wherein the process parameter is: vacuum degree is 1×10 1 ˜10 −3 , or being filled with argon, the melting temperature is 860˜1200° C., and the cooling rate is 10˜10 3  K/s. 
     The (ZrM)-(CuN)—Ni—Al-RE amorphous alloy of the present invention can be used in the fields of consumer electronics, medical and health, aerospace or transportation, for manufacturing complex components. 
     The (ZrM)-(CuN)—Ni—Al-RE amorphous alloy described in the present invention has the following characteristics: 
     1, The amorphous alloy has a high forming ability, in particular, has a good manufacturability, and its optimal glass froming ability is greater than 20 mm. Utilizing industrial manufacturing technology, the alloy repeated melting-casting preparation samples more than 4 times, still able to form amorphous, so as to ensure the quality and meet the actual production needs. 
     2, The mechanical properties of the amorphous alloy are as follows: the compressive fracture strength is greater than 1500 Pa, and the amorphous alloy has a more excellent antibacterial and bacteriostatic function, for the presence of Ag element is in the alloy. 
     3, The preparation raw materials can be industrial grade of metal Zr, Cu, Ni, Al, M, N and RE, and the vacuum is not demanding. 
     4, The amorphous alloy can be widely used in consumer electronics, health care, transportation and other fields, and is an ideal material for manufacturing complex, thin-walled parts, which has a broad application prospect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an amorphous alloy component. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     All raw materials (Zr, Hf, Ti, Cu, Ni, Al, Ag, Y, Gd, Sc) used in this embodiment are industrial grade metals, Zr and Ti metals are sponge zirconium, sponge titanium, Hf can be sponge zirconium containing a certain amount of Hf, which are prepared according to the atomic percentage. And then, prepare the mother alloy ingot by arc melting or induction melting, under the protection of argon. In order to ensure the uniform of the refined alloy ingot, the refined alloy ingot need to be flipped 3 to 4 times during the arc melting process of the mother alloy ingot, and then obtaining the mother alloy ingot by Cu mold casting and induction heating, wherein the heating temperature is about 1000° C., the vacuum is 10 −1 ˜10 −2  Pa. 
     Examples 1 to 23 shown in Table 1 (the same preparation process): 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Composition of (ZrM)—(CuN)—Ni—Al—RE alloy, amorphous  
               
               
                 size and mechanical properties 
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Amorphous  
                 Strength 
               
               
                 NO 
                 Alloy Composition (%) 
                 size (mm) 
                 (Mpa) 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 1 
                 Zr 50.4 Hf 0.4 Cu 35.9 Ag 0.1 Ni 4 Al 9 Y 0.2   
                 ≧8 
                 1830 
               
               
                 2 
                 Zr 50.4 Hf 0.4 Cu 35.9 Ag 0.1 Ni 4 Al 9 Gd 0.2   
                 ≧5 
                 1620 
               
               
                 3 
                 Zr 51.6 Hf 0.4 Cu 34.9 Ag 0.1 Ni 5 Al 7.5 Y 0.5   
                 ≧8 
                 1800 
               
               
                 4 
                 Zr 51.6 Hf 0.4 Cu 34.9 Ag 0.1 Ni 5 Al 7.5 Gd 0.5   
                 ≧6 
                 1630 
               
               
                 5 
                 Zr 50 Ti 2 Cu 34.9 Ag 0.1 Ni 5 Al 7.5 Y 0.5   
                 ≧6 
                 1820 
               
               
                 6 
                 Zr 50 Ti 2 Cu 34.9 Ag 0.1 Ni 5 Al 7.5 Gd 0.5   
                 ≧6 
                 1650 
               
               
                 7 
                 (Zr 51.8 Hf 0.4 Cu 35 Ag 0.1 Ni 6 Al 6.7 ) 98 Y 2   
                 ≧8 
                 1780 
               
               
                 8 
                 (Zr 54.6 Hf 0.4 Cu 29.9 Ag 0.1 Ni 5 Al 10 ) 98 Y 2   
                 ≧12 
                 1800 
               
               
                 9 
                 (Zr 63.9 Hf 0.5 Cu 18 Ag 0.1 Ni 10 Al 7.5 ) 98 Y 2   
                 ≧5 
                 1780 
               
               
                 10 
                 (Zr 54.6 Hf 0.4 Cu 29.9 Ag 0.1 Ni 5 Al 10 ) 99.5 Y 0.5   
                 ≧15 
                 1820 
               
               
                 11 
                 (Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10 ) 99.5 Y 0.5   
                 ≧20 
                 1800 
               
               
                 12 
                 (Zr 49.96 Hf 0.5 Cu 35.19 Ni 2.65 Ag 2.15 Al 9.55 ) 99.5 Y 0.5   
                 ≧12 
                 1812 
               
               
                 13 
                 (Zr 49.72 Hf 0.4 Cu 35.22 Ni 2.69 Ag 2.69 Al 9.28 ) 99.5 Y 0.5   
                 ≧20 
                 1810 
               
               
                 14 
                 (Zr 49.40 Hf 0.4 Cu 35.20 Ni 2.73 Ag 3.24 Al 9.03 ) 99.5 Y 0.5   
                 ≧20 
                 1810 
               
               
                 15 
                 (Zr 50.1 Hf 0.4 Cu 31.5 Ni 4 Al 11 Ag 3 ) 99.5 Y 0.5   
                 ≧20 
                 1890 
               
               
                 16 
                 (Zr 48.2 Hf 0.3 Cu 36 Ag 0.5 Ni 4 Al 9 Ti 2 ) 99.5 Y 0.5   
                 ≧12 
                 1790 
               
               
                 17 
                 Zr 55 Cu 30 Ni 5 Al 10   
                   4 mm 
                 1750 
               
               
                 18 
                 Zr 54 Ti 1 Cu 30 Ni 5 Al 10   
                 4.5 mm 
                 1760 
               
               
                 19 
                 Zr 54 Hf 1 Cu 30 Ni 5 Al 10   
                 4.5 mm 
                 1770 
               
               
                 20 
                 Zr 55 Cu 29.9 Ag 0.1 Ni 5 Al 10   
                   5 mm 
                 1740 
               
               
                 21 
                 Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10   
                   8 mm 
                 1790 
               
               
                 22 
                 (Zr 54.8 Cu 29.9 Ag 0.3 Ni 5 Al 10 ) 99.5 Y 0.5   
                  15 mm 
                 1800 
               
               
                 23 
                 (Zr 48.2 Hf 0.3 Cu 36.5 Ni 4 Al 9 Ti 2 ) 99.5 Y 0.5   
                 ≧10 
                 1785 
               
               
                   
               
            
           
         
       
     
     The antimicrobial properties of the amorphous alloy can be measured by a coating method (see JIS Z 2801-2000) to detect its sterilization rate against common  Escherichia coli  ATCC25922, wherein the concentration of bacteria is 4.2×10 5  cfu/ml. The results show that the bactericidal rate of the amorphous alloy against  Escherichia coli  is more than 99.9%. 
     Example 24 
     By utilizing (Zr54.4Hf0.4Cu29.9Ag0.3Ni5Al10)99.5Y0.5 alloy to prepare amorphous components by vacuum die casting method, under the conditions of induction melting 30 kg alloy, vacuum 10 −1 ˜10 −2  Pa and heating temperature 900˜1000° C. After repeating 5 times, the prepared component can still guarantee the amorphous structure of the alloy material. The prepared component is shown in  FIG. 1 . After Re-use 4 times, the alloy casted φ5 mm sample can still guarantee the formation of amorphous. 
     Comparative Example 1 
     The Zr55Cu30Ni5Al10 alloy is one of the Zr—Cu—Ni—Al quaternary amorphous alloys having strongest forming capacity, reported in the literature, and its forming capacity is φ30 mm. However, the alloy system requires a very demanding on the purity of the composition and preparation conditions. when employing industrial materials, under vacuum of 1×10 1 ˜10 −2  Pa, its amorphous size is merely φ4 mm; when adding separately a small amount of Hf or Ti element, the amorphous size of the Zr 54 Hf 1 Cu 30 Ni 5 Al 10  (Zr 54 Ti 1 Cu 30 Ni 5 Al 10 ) is merely φ4.5 mm; when adding separately a small amount of Ag element, the amorphous size of the Zr 55 Cu 29.9 Ag 0.3 Ni 5 Al 10  is φ5 mm; when adding simultaneously a small amount of Hf and Ag elements, the amorphous size of the Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10  is φ8 mm; when adding simultaneously a small amount of Ag and Y elements, the amorphous size of the (Zr 54.8 Cu 29.9 Ag 0.3 Ni 5 Al 10 ) 99.5 Y 0.5  is φ15 mm; and when adding simultaneously a small amount of Hf, Ag and Y elements, the amorphous size of the (Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10 ) 99.5 Y 0.5  is more than φ20 mm. 
     Comparative Example 2 
     Preparing the sample of Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10  amorphous alloy the second time, which has been crystallized partly, however, the sample of (Zr 54.4 Hf 0.4 Cu 29.9 Ag 0.3 Ni 5 Al 10 ) 99.5 Y 0.5  amorphous alloy repeats 4 times, which is still amorphous, and the sample is φ5×50 mm round bar.