Manganese-titanium intermediate alloy and preparation method and application thereof

Abstract

The invention belongs to the field of alloys, and particularly discloses a manganese-titanium intermediate alloy and a preparation method and application thereof. The manganese-titanium intermediate alloy is prepared by adding sponge titanium step by step according to a specific proportion and carrying out vacuum induction melting. According to the preparation method of the manganese-titanium intermediate alloy and the titanium alloy, the situation that a large amount of Mn element is burnt out in the smelting process can be reduced, so that the component content consistency and uniformity of the manganese-titanium intermediate alloy, the titanium alloy and the like are improved, and the metallurgical quality of the smelted alloy is guaranteed; meanwhile, the method is simple and easy to implement, can be achieved through one-time smelting, does not need to make raw materials into electrode blocks in advance, reduces the process complexity degree and the production cost, and is environmentally friendly and suitable for being widely applied and popularized in the alloy field.

Description

Technical Field

[0001] The invention belongs to the field of alloys, and in particular relates to a manganese-titanium master alloy and a preparation method and application thereof. Background Art

[0002] Titanium alloys, titanium aluminum alloys, titanium nickel alloys and other alloys have high chemical activity in the melt and can only be melted by vacuum melting or protective atmosphere melting methods such as vacuum induction melting, vacuum consumable melting, and electron beam melting. Mn, as a common alloying element, is widely added and used in the above alloy systems.

[0003] At present, pure Mn raw materials are usually added to titanium alloys, titanium aluminum alloys, and titanium nickel alloys containing Mn alloying elements in vacuum melting or protective atmosphere melting. For example, CN103820677B "A new β-γTiAl intermetallic compound material containing Mn and high Nb and its preparation method", CN103820672A "A Cr, Mn alloyed β phase solidified high Nb-TiAl alloy and its preparation method" and CN103834844B "A V, Mn alloyed β phase solidified high Nb-TiAl alloy and its preparation method" all use electrolytic manganese flake pure metal as raw material. However, due to the low melting point of Mn metal, which is only 1246℃, and the high saturated vapor pressure of Mn element, which is quite different from the saturated vapor pressure of other elements in the melt, such as the saturated vapor pressures of Ti and Mn elements are 0.04Pa (solid phase) and 1588Pa at 1500℃, respectively, the volatilization loss of Mn element with high vapor pressure during the melting process is relatively serious, and the higher the melting temperature and the lower the melting vacuum, the greater the Mn volatilization loss. The large amount of burning caused by the volatilization of Mn element will inevitably affect the composition consistency and uniformity of the smelted alloy ingot, and it is difficult to ensure the alloying effect of Mn element in the alloy.

[0004] The research directions for improving the above problems in the prior art mainly include the improvement of smelting equipment, replacement of raw materials and further optimization of process parameters. For example, CN117704801A (A smelting and pouring device and method for preparing TiAl-Mn alloy castings) relates to a smelting and pouring device and method for preparing TiAl-Mn alloy castings, which mainly reduces the volatilization of Mn elements by setting a gas protection cover during smelting and pouring; this type of method requires special equipment to implement, and the effect is general. The optimization of process parameters will bring about a very cumbersome process and is difficult to implement. Another example is CN110983079A (a method for preparing a titanium alloy ingot containing volatile elements), which uses an intermediate alloy and performs primary smelting (ion cooling furnace) and secondary smelting (vacuum consumable arc furnace) to prepare a titanium alloy containing volatile elements, and clarifies parameters such as smelting atmosphere, smelting power, smelting current, and stirring cycle. Although this method does not require special improved equipment to be implemented and the effect is relatively good, the existing intermediate alloy used in this method must be pressed into electrode blocks with other raw materials before the primary smelting, and must undergo secondary smelting, which has certain application limitations. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art. Based on this, the present invention provides a titanium-manganese intermediate alloy with a specific element content prepared by a specific process. When the intermediate alloy is applied to the preparation of titanium alloys, titanium-aluminum alloys and titanium-nickel alloys containing Mn components, the technical problem of large-scale volatilization and burning loss of Mn elements during the smelting process can be reduced.

[0006] Specifically, the present invention provides a method for preparing a manganese-titanium master alloy, comprising the following steps:

[0007] According to the nominal composition of the manganese-titanium master alloy, corresponding parts by weight of sponge titanium and metallic manganese are prepared; wherein the weight of the sponge titanium is recorded as 100 parts;

[0008] First, 25-50 parts (i.e. 1 / 4 to 1 / 2) of the sponge titanium and all the metallic manganese are used as the first raw material for vacuum induction melting. After the first raw material is completely melted, the remaining sponge titanium is added as the second raw material for vacuum induction melting. After the second raw material is completely melted, the manganese-titanium intermediate alloy is obtained.

[0009] The present invention adopts a two-step adding method of first mixing and melting a part of the sponge titanium with metallic manganese in a specific proportion, and then adding the remaining sponge titanium into the melt, and cooperates with the vacuum induction melting method, thereby effectively reducing the problem of large-scale volatilization and burning loss of Mn element during the melting process. The obtained manganese-titanium intermediate alloy has a more accurate composition (closer to the nominal composition), a lower impurity content, a more flexible adding method (no need to press in advance to prepare the electrode block), and a simple process.

[0010] On the basis of the above preparation method, the inventor determined based on theoretical analysis and experimental optimization that when the titanium content in the above manganese-titanium master alloy is 30%-36% by weight, the manganese-titanium master alloy with a specific content has a relatively high melting point, and the preparation method of the master alloy is designed accordingly. On the one hand, the manganese-titanium master alloy of the present invention, the raw materials are added in two steps, and the protective atmosphere smelting method is used to reduce the large amount of volatilization and burning loss of the Mn element during the preparation process to improve the uniformity of the master alloy, and at the same time, the impurity content of the manganese-titanium master alloy is well controlled by combining the thermodynamically stable oxide crucible preparation technology. On the other hand, when the manganese-titanium master alloy with a specific content is used in the process of preparing titanium alloys, titanium-nickel, titanium-aluminum and other alloys, the manganese-titanium master alloy with a higher melting point can be slowly released after being added to titanium alloys, titanium-nickel, titanium-aluminum and other alloys without causing local manganese enrichment in the melt and large amounts of volatilization losses, which has a beneficial effect on the uniformity of the alloy components of titanium alloys, titanium-nickel, titanium-aluminum and other alloys).

[0011] In some embodiments, the vacuum induction melting (a vacuum induction melting furnace may be used) is performed under a protective atmosphere, which is an inert gas atmosphere, such as argon or helium; wherein the pressure of the protective atmosphere is 0.05 MPa-0.1 MPa.

[0012] In some embodiments, the first raw material is added to an oxide crucible for vacuum induction melting; the oxide crucible is a thermodynamically stable oxide crucible such as a calcium oxide crucible, a magnesium oxide crucible, a zirconium oxide crucible, or a yttrium oxide crucible. The second raw material can be placed in a secondary feeding bin of a vacuum induction melting furnace.

[0013] In some embodiments, the metallic manganese is electrolytic manganese flakes; the purity of the titanium sponge is greater than 99.8%, and the purity of the metallic manganese is greater than 99.8%.

[0014] In some embodiments, in the above preparation method, after the above second raw material is completely melted, it is refined and then cast into a metal mold to obtain the above manganese-titanium master alloy, wherein the refining temperature is 1340°C-1400°C and the time is 1min-5min.

[0015] The present invention provides a manganese-titanium master alloy prepared by the above-mentioned preparation method. In which, by weight percentage, the titanium content is 30%-36%, and the impurity content satisfies: O≤0.04%, N≤0.01%. The manganese-titanium master alloy can be well used in the preparation of alloys including: (titanium alloys containing Mn components, titanium-aluminum alloys, titanium-nickel alloys, etc.), steel containing both Mn components and Ti components, or manganese alloys containing Ti components), can reduce the problem of large-scale volatilization and burning loss of Mn elements during smelting, the obtained alloy composition is more accurate (closer to the nominal composition), and the addition method is more flexible (no need to press and prepare electrode blocks in advance), and the smelting operation is simple.

[0016] The beneficial effects of the present invention are as follows: the preparation method of the manganese-titanium intermediate alloy and the titanium alloy provided by the present invention can reduce the large-scale burning loss of the Mn element during the smelting process, thereby improving the consistency and uniformity of the component content of the manganese-titanium intermediate alloy and the titanium alloy, and ensuring the metallurgical quality of the smelted alloy; at the same time, the method of the present invention is simple and easy to implement, can be achieved by one-time smelting, and there is no need to make the raw materials into electrode blocks in advance, which reduces the complexity of the process and the production cost, is green and environmentally friendly, and is suitable for large-scale promotion and application in the alloy field. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is an electron photograph of the manganese-titanium master alloy ingot prepared in Example 1. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments and drawings to clearly and completely describe the concept and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0019] Example 1: Preparation of manganese-titanium master alloy

[0020] A manganese-titanium master alloy, the nominal composition of which by mass percentage includes: Ti 31%, Mn 69%. The preparation method thereof includes the following steps:

[0021] Weigh 31% of sponge titanium (purity 99.85%) and 69% of electrolytic manganese flakes (purity 99.87%) by mass, add all the electrolytic manganese flakes and 1 / 3 of the mass of sponge titanium into a calcium oxide crucible (melting weight 2 kg), place it in a vacuum induction furnace, and place the remaining 2 / 3 of the mass of sponge titanium in the secondary feeding bin of the vacuum induction melting furnace.

[0022] The vacuum induction melting furnace is filled with 0.05MPa argon as a protective gas, and the power is supplied for melting. After all the raw materials in the crucible are melted, the remaining sponge titanium in the secondary feeding bin is added to the melt for further melting. After it is completely melted, it is refined at 1450℃ for 2min, and then cast into a metal mold. After it is completely cooled, the manganese-titanium intermediate alloy is obtained. Its electronic photo is as follows Figure 1 shown.

[0023] Comparative Example 1: (Ti content less than 30%)

[0024] A manganese-titanium master alloy, the nominal composition of which by mass percentage includes: Ti 20%, Mn 80%. The preparation method thereof includes the following steps:

[0025] Weigh 20% of sponge titanium (purity 99.85%) and 80% of electrolytic manganese flakes (purity 99.87%) by mass, add all the electrolytic manganese flakes and 1 / 3 of the mass of sponge titanium into a calcium oxide crucible (melting weight 2 kg), place it in a vacuum induction furnace, and place the remaining 2 / 3 of the mass of sponge titanium in the secondary feeding bin of the vacuum induction melting furnace.

[0026] The vacuum induction melting furnace is filled with 0.05MPa argon as a protective gas, and power is supplied for melting. After all the raw materials in the crucible are melted, the remaining sponge titanium in the secondary feeding bin is added to the melt for further melting. After complete melting, it is refined at 1450°C for 2min, and then cast into a metal mold. After complete cooling, the manganese-titanium intermediate alloy is obtained.

[0027] Comparative Example 2: (Ti content higher than 36%)

[0028] A manganese-titanium master alloy, the nominal composition of which by mass percentage includes: Ti 46%, Mn 56%. The preparation method thereof includes the following steps:

[0029] Weigh 40% of titanium sponge (purity 99.85%) and 60% of electrolytic manganese flakes (purity 99.87%) by mass, add all the electrolytic manganese flakes and 1 / 3 of the titanium sponge into a calcium oxide crucible (melting weight 2 kg), place it in a vacuum induction furnace, and place the remaining 2 / 3 of the titanium sponge in the secondary feeding bin of the vacuum induction melting furnace.

[0030] The vacuum induction melting furnace is filled with 0.05MPa argon as a protective gas, and power is supplied for melting. After all the raw materials in the crucible are melted, the remaining sponge titanium in the secondary feeding bin is added to the melt for further melting. After complete melting, it is refined at 1450°C for 2min, and then cast into a metal mold. After complete cooling, the manganese-titanium intermediate alloy is obtained.

[0031] Effect test 1

[0032] The manganese-titanium intermediate alloys (i.e., manganese-titanium intermediate alloy ingots) prepared in Example 1 and Comparative Examples 1 and 2 were subjected to element content analysis to determine the contents of manganese, titanium and impurity elements therein, and the melting points were analyzed. The results are shown in Table 1.

[0033] Table 1 Melting point (°C) and composition (wt.%) of manganese-titanium master alloy ingot

[0034] Melting point Ti Mn O N H Example 1 1325 31.08 68.91 0.030 0.0087 0.00034 Comparative Example 1 1290 20.88 79.12 0.035 0.0095 0.00027 Comparative Example 2 1280 46.13 53.87 0.080 0.0130 0.00082

[0035] As can be seen from Table 1, the element content (Mn and Ti) of the manganese-titanium intermediate alloy prepared by the method of the present invention is very close to the nominal content, which fully demonstrates that the method of the present invention can reduce the situation of large-scale burnout of the Mn element; and the impurity content of the prepared manganese-titanium intermediate alloy, including O, is also low; the manganese-titanium intermediate alloy prepared by the present invention can further ensure the metallurgical quality of alloys such as titanium alloys.

[0036] Example 2: Application in NiTiMn alloy

[0037] The manganese-titanium master alloy prepared in Example 1 is used as a raw material to prepare a nickel-titanium-manganese alloy having a composition of 50Ni-30Ti-20Mn (at.%). The preparation method comprises the following steps:

[0038] The nominal alloy composition (50Ni-30Ti-20Mn, at.%) is converted into weight percentage (53.56%Ni-26.26%Ti-20.09%Mn), and the weight of the corresponding raw materials is calculated according to the total weight of 5kg nickel-titanium alloy, i.e. 860g of sponge titanium, 2683g of electrolytic nickel, and 1457g of the TiMn master alloy obtained in Example 1 (in terms of mass percentage, the Mn content in the TiMn master alloy is 68.91%, i.e. 1004g of Mn and 453g of Ti). A CaO crucible is used for vacuum induction melting, and the raw materials are melted once and then cast to obtain an alloy ingot, and the manganese content of the ingot is uniform and the impurity content is low.

[0039] Example 3: Application in titanium-zirconium-manganese-chromium alloy

[0040] The difference from Example 2 is that the alloy composition used is different. The alloy composition of this example is Ti1.0Zr0.1Mn1.1Cr0.9. The preparation method includes the following steps:

[0041] The nominal alloy composition (Ti1.0Zr0.1Mn1.1Cr0.9) is converted into a weight percentage content (29.15%Ti-3.23%Zr-36.80%Mn-28.49%Cr), and the weight of the corresponding raw materials is calculated according to 5kg, i.e. 628g of titanium sponge, 278g of zirconium sponge, 1425g of metallic chromium, and 2670g of the TiMn master alloy obtained in Example 1 (in terms of mass percentage, the Mn content in the TiMn master alloy is 68.91%, i.e. 1840g of Mn and 830g of Ti). A CaO crucible is used for vacuum induction melting, and the raw materials are melted once and then cast to obtain an alloy ingot, the manganese content of the ingot is uniform, and the impurity content is less.

[0042] Example 4: TC2 alloy

[0043] The differences from Example 2 and Example 3 are the following two points: 1) the alloy composition is different, the composition of this example is Ti-4Al-1.5Mn (wt.%), 2) the smelting crucible is different, this case uses a water-cooled copper crucible, and the smelting times are two times.

[0044] The specific steps include:

[0045] The weight of the corresponding raw materials is calculated according to the nominal composition of 5 kg alloy (Ti-4Al-1.5Mn, wt.%), i.e. 4691 g of titanium sponge, 200 g of aluminum metal, and 109 g of the TiMn master alloy prepared in Example 1 (in terms of mass percentage, the Mn content in the TiMn master alloy is 68.91%, i.e., 75 g of Mn and 34 g of Ti). All the above raw materials are placed in a water-cooled copper crucible for vacuum induction melting. After the raw materials are melted, they solidify in the crucible, and after cooling, they are turned upside down and re-smelted, and cast to obtain an alloy ingot.

[0046] Effect Test 2

[0047] The content of the upper part and the bottom part of the alloy ingots prepared in Example 2 to Example 4 were detected respectively, and the results of the element content are shown in Table 2.

[0048] Table 2 Composition of three alloy ingots smelted from manganese-titanium master alloy raw materials (wt.%)

[0049]

[0050] As can be seen from Table 2, by using the manganese-titanium master alloy of the present invention as a raw material and limiting its element content within a specific range, and applying it to vacuum induction melting, quick melting and preparation of titanium alloys, nickel-titanium, titanium-zirconium-manganese-chromium and other alloys are achieved, and the large amount of volatilization and burning loss of the Mn element is greatly reduced, thereby ensuring the consistency and uniformity of the components in the smelted alloy; at the same time, the content of impurities such as oxygen is also low, and the more complicated process steps in the prior art are not required.

[0051] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A method for preparing a manganese-titanium master alloy, characterized in that: The following steps are involved: According to the nominal composition of the manganese-titanium master alloy, corresponding parts by weight of sponge titanium and metal manganese are prepared; wherein the weight of the sponge titanium is recorded as 100 parts; First, 25-50 parts of the sponge titanium and the metal manganese are used as the first raw materials for vacuum induction melting. After the first raw materials are completely melted, the remaining sponge titanium is added as the second raw material for vacuum induction melting. After the second raw material is completely melted, the manganese-titanium intermediate alloy is obtained.

2. The preparation method according to claim 1, characterized in that: In the manganese-titanium master alloy, the content of titanium is 30%-36% by weight.

3. The preparation method according to claim 1, characterized in that: The vacuum induction melting is carried out under a protective atmosphere, which is an inert gas atmosphere; the pressure of the protective atmosphere is 0.05MPa-0.1MPa.

4. The preparation method according to claim 1, characterized in that: The first raw material is added into an oxide crucible for vacuum induction melting; and a vacuum induction melting furnace is used for vacuum induction melting.

5. The preparation method according to claim 1, characterized in that: The metallic manganese is electrolytic manganese flakes; and / or the purity of the titanium sponge is greater than 99.8%, and the purity of the metallic manganese is greater than 99.8%.

6. The preparation method according to claim 1, characterized in that: After the second raw material is completely melted, it is refined and then cast into a metal mold to obtain the manganese-titanium intermediate alloy.

7. A manganese-titanium master alloy, characterized in that: Prepared by the preparation method according to any one of claims 1 to 6.

8. The manganese-titanium master alloy according to claim 7, characterized in that: In terms of weight percentage, the titanium content is 30%-36%, and the impurity content satisfies: O≤0.04%, N≤0.01%.

9. Use of the manganese-titanium master alloy as claimed in claim 7 or 8 in preparing alloys.

10. The use according to claim 9, characterized in that: The alloy includes: a titanium alloy containing a Mn component, a titanium-aluminum alloy containing a Mn component, a titanium-nickel alloy containing a Mn component, steel containing both a Mn component and a Ti component, or a manganese alloy containing a Ti component.

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