阅读说明：本技术 镁镍中间合金及其制备方法 (Magnesium-nickel intermediate alloy and preparation method thereof ) 是由 吕晶 姚茂海 李�杰 张晓梅 何锋 李俊辉 于 2020-11-20 设计创作，主要内容包括：本发明公开了一种镁镍中间合金及其制备方法。制备方法包括：称取镁锭和镍块并烘干；将部分镁锭放入非真空中频电磁感应炉中加热,镁锭开始熔化时通入SF-6与N-2的混合气体；镁锭全部熔化后放入镍块,并持续通入SF-6与N-2的混合气体,镍块完全反应后充分搅拌熔体；关闭非真空中频电磁感应炉,将剩余部分镁锭加入到熔体中,以对熔体进行降温处理,搅拌均匀,浇铸。本发明以普通镁锭以及镍为原材料,利用普通非真空中频电磁感应炉,通过熔炼工艺控制,生产出的镁镍合金表面质量好、成分均匀、夹渣量低,能在常规的环境下保存较长时间；生产过程操作简单,镁合金熔炼烧损少,设备要求低,产品质量稳定性好,可实现批量化生产。(The invention discloses a magnesium-nickel intermediate alloy and a preparation method thereof. The preparation method comprises the following steps: weighing magnesium ingots and nickel blocks and drying; heating part of magnesium ingot in a non-vacuum medium frequency electromagnetic induction furnace, and introducing SF when the magnesium ingot begins to melt 6 And N 2 The mixed gas of (3); putting the magnesium ingot into a nickel block after the magnesium ingot is completely melted, and continuously introducing SF 6 And N 2 The mixed gas of (1) and the nickel block are fully stirred after complete reaction; and closing the non-vacuum intermediate frequency electromagnetic induction furnace, adding the rest magnesium ingot into the melt to perform cooling treatment on the melt, uniformly stirring and casting. The invention takes common magnesium ingot and nickel as raw materials, utilizes a common non-vacuum intermediate frequency electromagnetic induction furnace, and is controlled by a smelting process, so that the produced magnesium-nickel alloy has good surface quality, uniform components and low slag inclusion amount, and can be preserved for a long time in a conventional environment; simple operation in the production process, less burning loss in the smelting of the magnesium alloy, low equipment requirement, good product quality stability and practicabilityAnd (4) batch production.)

1. The preparation method of the magnesium-nickel intermediate alloy is characterized by comprising the following steps of:

step S1, weighing magnesium ingots and nickel blocks, and drying;

step S2, putting the magnesium ingot accounting for 60-85% of the total weight of the magnesium ingot into a crucible of a non-vacuum medium-frequency electromagnetic induction furnace for heating, and introducing SF when the magnesium ingot begins to melt₆And N₂The mixed gas of (3);

step S3, putting nickel blocks into the molten magnesium ingot, and continuously introducing SF₆And N₂The mixed gas of (1) and the nickel block are fully stirred after complete reaction;

step S4, closing the non-vacuum intermediate frequency electromagnetic induction furnace, and adding the rest magnesium ingot into the melt to cool the melt;

and step S5, casting.

2. The method for preparing the magnesium-nickel intermediate alloy according to claim 1, wherein in the step S1, the weight ratio of the magnesium ingot to the nickel block is 1 (0.25-0.35).

3. The method of claim 1, wherein the mixed gas is SF₆And N₂The mixing ratio of (1) to (25-100).

4. The method for preparing the magnesium-nickel intermediate alloy according to claim 1, wherein the step S3 further comprises: and reducing the power of the non-vacuum medium-frequency electromagnetic induction furnace.

5. The method for preparing the magnesium-nickel intermediate alloy according to claim 1, wherein in step S5, the mixture is stirred uniformly, and casting is performed when the temperature of the melt is reduced to 700-780 ℃.

6. The method of claim 1, wherein in step S5, the melt flows into the mold through a buffer device, wherein the buffer device is a spoon-shaped structure.

7. The method for preparing the magnesium-nickel intermediate alloy according to claim 6, wherein the buffer device comprises: a material chamber for the inflow of the melt and a flow channel communicated with the material chamber and used for the outflow of the melt, wherein,

the inner bottom of the material chamber is lower than the inner bottom of the flow channel, so that the melt overflowing from the material chamber flows through the flow channel;

the width of the connecting end of the flow channel and the material chamber is the same as that of the material chamber, and the width of the other end of the flow channel is smaller than that of the material chamber and is 50% -80% of the width of the material chamber.

8. The preparation method of the magnesium-nickel intermediate alloy according to claim 7, wherein in the buffer device, the material chamber is rectangular, and the length, the width and the height of the material chamber are respectively 15-30 cm, 15-30 cm and 4-8 cm; the height of the flow channel is 1/2 of the material chamber.

9. The method of claim 1, wherein the SF is continuously supplied into the crucible, the casting container and the mold during the casting process in step S5₆And N₂The mixed gas of (3); and after the casting is finished, the mixed gas introduced into the crucible and the casting container is closed, and after the liquid melt is completely solidified, the mixed gas introduced into the casting mold is closed.

10. A magnesium-nickel intermediate alloy, characterized by being prepared by the method for preparing the magnesium-nickel intermediate alloy according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of intermediate alloy preparation, in particular to a magnesium-nickel intermediate alloy and a preparation method thereof.

Background

The magnesium-nickel alloy is easy to corrode, and the biodegradable nickel-magnesium-containing alloy is developed in recent years by utilizing the property, and is used for the degradable nickel-magnesium-containing alloy for exploiting shale gas. The magnesium-nickel alloy has good hydrogen storage performance and is the most promising substitute for LaNi in the future₅The hydrogen storage material of (1). The high-quality magnesium-nickel intermediate alloy is the basis for the application and development of the nickel-magnesium-containing alloy.

Chinese patent CN1165631C discloses a method for preparing Mg₂A method for preparing a Ni-Ni alloy by utilizing magnesium powder and nickel powder through mixing, pressing and sintering processes is particularly disclosed, but the method for preparing the Ni-Mg alloy by utilizing a powder metallurgy mode has high cost and is difficult to realize large-scale production and application.

The chinese application CN111139386A discloses a method for preparing a high-strength soluble magnesium alloy material, which refers to a preparation process of a magnesium-nickel intermediate alloy, but in the preparation process of the magnesium-nickel alloy, a melt protection measure is not specified, a protection mode in a melt casting process is not specified, and ingot casting quality is difficult to ensure.

Magnesium is easy to be burnt in the smelting process, the alloying reaction of magnesium and nickel needs higher temperature, no protective measures are taken, the problems of serious burning loss, blackening of the surface of a finished product, more slag inclusions and the like easily occur in the smelting process of the magnesium-nickel alloy, and the storage and the use of the intermediate alloy are seriously influenced. Common melt protection measures include gas protection, molten salt coverage protection, and protection by adding protective alloy elements. The covering protection by using molten salt can cause slag inclusion of the melt, and other elements can be introduced by using a method of adding a protective element.

In addition, during the casting process, the problem of slag inclusion of the melt needs to be controlled, otherwise, the produced magnesium-nickel alloy is corroded in a short time, and the storage and the use of the product are influenced. In the prior art, the problem that the temperature of a fused mass is difficult to control and the fused mass is easy to over-fire when the magnesium-nickel alloy is produced by using a non-vacuum intermediate frequency electromagnetic induction furnace also exists.

Disclosure of Invention

Based on the problems, the invention aims to provide a preparation method of a magnesium-nickel intermediate alloy, which takes a common magnesium ingot and nickel as raw materials, utilizes a common non-vacuum medium-frequency electromagnetic induction furnace, and is controlled by a smelting process, so that the produced magnesium-nickel intermediate alloy has the advantages of good surface quality, uniform components, low slag inclusion amount, long preservation time in a conventional environment, simple production process operation, less melting loss of the magnesium alloy, low equipment requirement, good product quality stability and batch production.

The invention also aims to provide the magnesium-nickel intermediate alloy.

The above purpose of the invention is realized by the following technical scheme:

according to one aspect of the invention, the preparation method of the magnesium-nickel intermediate alloy provided by the invention comprises the following steps:

step S1, weighing magnesium ingots and nickel blocks, and drying;

step S2, putting the magnesium ingot accounting for 60-85% of the total weight of the magnesium ingot into a crucible of a non-vacuum medium-frequency electromagnetic induction furnace for heating, and introducing SF when the magnesium ingot begins to melt₆And N₂The mixed gas of (3);

step S3, after the magnesium ingot is completely melted, putting a nickel block and continuously introducing SF₆And N₂After the nickel block is completely reacted, fully stirring the melt;

step S4, closing the non-vacuum intermediate frequency electromagnetic induction furnace, and adding the rest magnesium ingot into the melt to cool the melt;

and step S5, casting.

Preferably, in step S1, the weight ratio of the magnesium ingot to the nickel block is 1 (0.25-0.35).

Preferably, in all the mixed gases of the present invention, SF₆And N₂The mixing ratio of (1) to (25-100).

Preferably, in step S3, the method further includes: and reducing the power of the non-vacuum medium-frequency electromagnetic induction furnace in the reaction process of the nickel block and the magnesium liquid. Furthermore, the power can be reduced to 20-25 KW. For example, it may be reduced to 25 KW.

Preferably, in step S5, the mixture is stirred uniformly, and when the temperature of the melt is reduced to 700 to 780 ℃, casting is performed.

Preferably, in step S5, during casting, the melt flows into the mold through a buffer device, which is a spoon-shaped structure. The invention skillfully designs the spoon-shaped casting buffer device, which can reduce the flow speed of melt flowing into a mold, reduce the slag inclusion amount, intercept the miscible substances of metal and metal oxide and improve the quality of cast ingots.

Preferably, the buffering means comprises: the casting mold comprises a material chamber for melt to flow in and a flow channel communicated with the material chamber and used for flowing out the melt, wherein the inner bottom of the material chamber is lower than the inner bottom of the flow channel, so that the melt overflowing from the material chamber flows to the casting mold through the flow channel; the width of runner and material room link is the same with the material room, and the width of the other end is less than the width of material room, and is 50 ~ 80% of material room width.

Preferably, in the buffer device, the material chamber is rectangular, and the length, width and height of the material chamber are respectively 15-30 cm, 15-30 cm and 4-8 cm; the height of the flow channel is 1/2 of the material chamber. The material chamber and the flow channel in the buffer device can be integrally formed, but are not limited to the above, and can also be formed by connecting.

Preferably, in step S5, SF is continuously introduced into the crucible, the casting container and the mold during casting₆And N₂The mixed gas of (3); and after the casting is finished, the mixed gas introduced into the crucible and the casting container is closed, and after the liquid melt is completely solidified, the mixed gas introduced into the surface of the cast ingot in the casting mold is closed.

According to another aspect of the invention, the invention provides a magnesium-nickel intermediate alloy which is prepared by adopting the preparation method.

Compared with the prior art, the method takes the common magnesium ingot and the nickel as raw materials, utilizes the common non-vacuum intermediate frequency electromagnetic induction furnace, is controlled by the smelting process, produces the magnesium-nickel alloy with good surface quality, uniform components and low slag inclusion, can be preserved for a long time in the conventional environment, is simple in production process operation, has less smelting loss of the magnesium alloy, low equipment requirement and good product quality stability, and can be produced in batch.

The advantages of the invention are also shown in the following aspects:

1) according to the invention, the alloying temperature of magnesium and nickel is reduced by controlling the proportion of magnesium and nickel, the adding mode of the magnesium ingot is controlled, the magnesium ingot is added twice, the melt temperature is effectively reduced, and the over-high melt temperature is avoided. The first addition amount is controlled within the range of 60-85% of the total weight of the magnesium ingot, so that the problem that the burning loss of magnesium is accelerated due to the fact that the nickel content in a melt is higher and the temperature of the melt reaches or exceeds 980 ℃ because the first addition amount of magnesium is too low and nickel is completely dissolved is solved; the problems that the magnesium adding amount is too high for the first time, the cooling effect of the magnesium ingot cannot meet the requirement, and the quality of a cast product is influenced due to overhigh casting temperature are solved.

2) The invention controls the casting temperature of the melt in a proper range, ensures the fluidity of the melt, and simultaneously avoids irreversible burning loss caused by violent reaction with air after the surface protective film of the melt is broken in the casting process of the high-temperature melt.

3) The invention also skillfully designs a spoon-shaped casting buffer device, which can effectively control the speed of the metal melt flowing into the casting mold, so that the melt can stably fill the casting mold, and the problem of slag inclusion caused by turbulent flow formed by excessively high melt flow speed is solved; meanwhile, the buffer device can also effectively intercept miscible substances formed by metals and metal oxides in the melt.

4) The invention uses SF in the whole course₆And N₂The mixed gas protects the melt, reduces burning loss and improves product quality.

5) The magnesium-nickel alloy produced by the method has the advantages of uniform components, good surface quality, silver-gray fracture, no slag inclusion visible to naked eyes and total production yield of over 96 percent.

6) The production process of the magnesium-nickel intermediate alloy is simple to operate, additional equipment is not required, waiting for the temperature reduction of the melt is not required, the production cost is saved, and the production efficiency is improved.

Drawings

FIG. 1 is a graph showing the distribution of Ni content (wt%) in 61 lots of products obtained in example 1 of the present invention;

FIG. 2 is a schematic structural view of the casting buffer device of the present invention;

FIG. 3 is a schematic external view of a product produced in example 1 of the present invention;

FIG. 4 is a schematic cross-sectional view of a product produced in example 1 of the present invention.

In fig. 2, 10 chambers, 20 flow channels.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The preparation method of the magnesium-nickel intermediate alloy provided by the invention specifically comprises the following steps:

(1) weighing a certain amount of magnesium ingot and nickel block, and drying; wherein the weight ratio of the magnesium ingot to the nickel block is 1: 0.25-0.35.

(2) Weighing magnesium ingots accounting for 60-85% of the total weight of the magnesium ingots weighed in the step (1), putting the magnesium ingots into a crucible of a non-vacuum medium-frequency electromagnetic induction furnace for heating, and introducing SF into the crucible when the magnesium ingots start to melt₆And N₂The mixed gas of (3) protects the melt. Wherein, the use of the non-vacuum intermediate frequency electromagnetic induction furnace can avoid the volatilization of magnesium under the vacuum condition. SF in mixed gas₆And N₂Mixing ratio of (i.e. SF)₆:N₂＝1:25～100。

(3) After the magnesium ingot in the crucible is completely melted, putting the dried nickel block into the crucible, and continuously introducing SF on the surface of the melt₆And N₂The mixed gas of (1).

(4) When the melt is heated to a certain temperature, the nickel block begins to react with the magnesium liquid (the general reaction temperature is 800-850 ℃), and in order to avoid the overhigh melt temperature, the power of the non-vacuum medium-frequency electromagnetic induction furnace needs to be properly reduced. Further, the voltage can be reduced to 20-25 KW, for example, to about 25 KW.

(5) And fully stirring the melt after the nickel block completely reacts.

(6) And closing the power supply of the non-vacuum intermediate frequency electromagnetic induction furnace, and adding the rest magnesium ingot into the melt to cool the melt. The temperature of the melt is about 900-950 ℃ before cooling.

(7) Stirring uniformly, and casting when the temperature of the melt is reduced to 700-780 ℃.

(8) During casting, the melt flows into the casting mold after passing through the buffer device, so that the flow rate of the melt can be reduced, and partial oxidation slag inclusion can be intercepted. The buffer device is a self-made spoon-shaped buffer device, so that the flow speed of a melt flowing into a mold can be reduced, the slag inclusion amount is reduced, a mixed solution of metal and metal oxide is intercepted, and the quality of cast ingots is improved.

(9) During casting, SF is continuously introduced into the crucible, the casting container and the casting mold₆And N₂The mixed gas is used for avoiding the burning loss of the melt from influencing the quality of the cast ingot.

(10) After the casting is finished, the mixed gas which is introduced into the crucible and the casting container is closed, and SF is continuously introduced into the surface of the cast ingot in the casting mold₆And N₂The mixed gas is closed after the liquid melt is completely solidified.

Fig. 2 schematically shows the structure of the homemade spoon-shaped buffer device of the present invention, which comprises, as shown in fig. 2: a material chamber 10 for the inflow of the melt, and a flow passage 20 communicated with the material chamber 10 for the outflow of the melt. Wherein, the inner bottom of the material chamber 10 is lower than the inner bottom of the flow channel 20; the width of the connecting end of the flow channel 20 and the material chamber 10 is the same as that of the material chamber 10, and the width of the other end is smaller than that of the material chamber 10. Further, the width of the other end of the flow channel 20 may be 50-80% of the width of the material chamber 10.

The material chamber 10 can be rectangular, and the ratio of the length, the width and the height of the material chamber can be 15-30 cm, 15-30 cm and 4-8 cm. The height of the flow channel 20 may be 1/2 of the height of the material chamber 10, but is not limited thereto. The term "height" as used herein refers to the height of the interior of the material chamber 10 and the flow channel 20. Fig. 2 also shows a schematic operation diagram of the buffering device, as shown in fig. 2, the melt is poured into the material chamber 10, part of slag inclusion and metal oxide mixed solution are intercepted by the material chamber 10, and then the melt flows into the casting mold through the flow channel 20 after overflowing from the material chamber 10, so as to play a role in reducing the flow rate of the melt.

The technical scheme of the invention is described in detail by combining the specific embodiment of the invention as follows:

example 1

(1) Weighing 25.02Kg of magnesium ingot and 7.76Kg of 1# nickel, and drying;

(2) 15-21 Kg of magnesium ingot weighed in the step (1) is put into a crucible in a non-vacuum medium-frequency electromagnetic induction furnace for heating, and SF (sulfur hexafluoride) is introduced into the crucible when the magnesium ingot starts to melt₆And N₂The mixture ratio is 1: 75, protecting the molten magnesium;

(3) after the magnesium ingot put into the furnace is completely melted, putting the dried 1# nickel block into a crucible, and continuously introducing SF into the surface of the melt₆And N₂The mixture ratio is 1: 75 of a mixed gas protective melt;

(4) when the temperature of the melt rises to 800-850 ℃, the nickel block starts to react with magnesium liquid, and at the moment, in order to avoid overhigh temperature of the melt, the power of a non-vacuum medium-frequency electromagnetic induction furnace is reduced to 25KW (the temperature is increased to 50KW during normal smelting);

(5) fully stirring the melt after the nickel block is completely dissolved;

(6) closing a power supply of the non-vacuum medium-frequency electromagnetic induction furnace, adding the magnesium ingot which is weighed in the step (2) into the melt, and cooling the melt;

(7) after stirring uniformly, reducing the temperature of the melt to 760 ℃, and casting;

(8) during casting, firstly, uniformly and slowly pouring the melt into a spoon-shaped buffer device, wherein the melt overflows from a material chamber 10 of the buffer device and flows into a casting mold stably through a flow channel 20;

(9) during casting, SF is continuously introduced into the crucible, the casting container and the casting mold₆And N₂The mixture ratio is 1: 75 of a mixed gas;

(10) after the casting is finished, the protective gas introduced into the crucible and the casting container is closed; and continuously introducing SF to the surface of the ingot₆And N₂The mixture ratio is 1: 75 until it is completely solidified, and then the protective gas to the surface of the ingot is closed.

Fig. 3 shows the appearance of the product prepared in example 1, and fig. 4 shows the cross-sectional structure of the product. As shown in figures 3-4, the product has uniform components, good surface quality, silver gray fracture, and no slag inclusion visible to the naked eye.

According to the invention, 61 batches of products are prepared by the preparation method of example 1, and a Ni content (wt%) distribution curve diagram is drawn on the 61 batches of products, as shown in fig. 1, the weight percentage content distribution of nickel elements in the 61 batches of products prepared by the invention is concentrated, and the proportion in a component interval of 23.5 +/-1% is 91.8%.

Example 2

(1) Weighing 28.4Kg of magnesium ingot and 8.8Kg of 1# nickel, and drying;

(2) taking 17-24 Kg of magnesium ingot weighed in the step (1), putting the magnesium ingot into a non-vacuum medium-frequency electromagnetic induction furnace for heating, and introducing SF6 into a crucible when the magnesium ingot starts to melt, wherein the ratio of the SF6 to N2 is 1: 85 to protect the magnesium in the molten state;

(3) after the magnesium ingot put into the furnace is completely melted, putting the dried 1# nickel block into a crucible, and continuously introducing SF6 into the surface of the melt to be mixed with N2 in a ratio of 1: 85 of mixed gas protective melt;

(4) when the temperature of the melt rises to about 800-850 ℃, the nickel block starts to react with the magnesium liquid, and at the moment, in order to avoid overhigh temperature of the melt, the power of a non-vacuum medium-frequency electromagnetic induction furnace is reduced to 25KW (the temperature is increased to 50KW during normal smelting);

(5) fully stirring the melt after the nickel block completely reacts;

(6) closing a power supply of the non-vacuum medium-frequency electromagnetic induction furnace, adding the magnesium ingot which is weighed in the step (2) into the melt, and cooling the melt;

(7) after stirring uniformly, reducing the temperature of the melt to 755 ℃, and casting;

(8) during casting, firstly, uniformly and slowly pouring the melt into a spoon-shaped buffer device, wherein the melt overflows from a material chamber 10 of the buffer device and flows into a casting mold stably through a flow channel 20;

(9) during casting, SF is continuously introduced into the crucible, the casting container and the casting mold₆And N₂The mixture ratio is 1: 85 of mixed gas;

(10) after the casting is finished, the protective gas introduced into the crucible and the casting container is closed; and continuously introducing SF to the surface of the ingot₆And N₂The mixture ratio is 1: 85 until they are completely solidified, and then the protective gas to the surface of the ingot is closed.

The final product obtained in example 2 has uniform components, good surface quality, silver-gray fracture and no slag inclusion visible to naked eyes.

The invention takes common magnesium ingot and nickel as raw materials, utilizes a common non-vacuum intermediate frequency electromagnetic induction furnace, skillfully designs the spoon-shaped casting buffer device through the control of a smelting process, and the produced magnesium-nickel alloy has good surface quality, uniform components and low slag inclusion amount, can be preserved for a long time in a conventional environment, has simple production process operation, less magnesium alloy smelting burning loss, low equipment requirement and good product quality stability, and can realize batch production.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.