A high-entropy layered transition layer material for titanium-steel connection and a preparation method thereof

Abstract

The application discloses a high-entropy layered transition layer material for titanium-steel connection and a preparation method thereof, and belongs to the technical field of alloy or non-ferrous metal processing. Flaky metals are stacked together, rolling is carried out at room temperature, the rolled product is folded along the length direction, and the rolling is recycled to a predetermined pass, and then the obtained intermediate sample is made into a bulk material; the bulk material is subjected to heat treatment-heat rolling and thinning, and finally the high-entropy layered transition layer material for titanium-steel connection is obtained. Through the method, the metals are subjected to severe plastic deformation, the layer spacing is reduced, and partial solid solution occurs between the metals after rolling. After heat treatment, element diffusion is completed and a layered non-uniform structure is maintained, and the alloy defects are further reduced through heat rolling and thinning. The application has the advantages of simple process, single-phase structure of the prepared alloy, and relatively high hardness.

Description

Technical Field

[0001] This invention relates to the field of alloy or non-ferrous metal processing technology, and in particular to a high-entropy layered transition layer material for titanium-steel bonding and its preparation method. Background Technology

[0002] Titanium / steel composite plates not only possess the corrosion resistance of titanium but also the excellent strength, toughness, and processing performance of carbon steel, along with low cost, making them promising for a wide range of engineering applications. In recent years, they have been widely used in aerospace, marine engineering, chemical industry, pipeline engineering, and other fields. However, due to the differences in properties between titanium and iron, they easily form hard and brittle intermetallic compounds, severely reducing the interfacial bonding strength.

[0003] In recent years, high-entropy intermetallic compounds, developed based on high-entropy alloys, have received increasing attention. High-entropy intermetallic compounds are ordered metallic materials. Their sublattices maintain a long-range ordered structure, exhibiting the characteristics of intermetallic compounds. However, within each sublattice, multiple elements randomly occupy positions, maintaining the properties of a solid solution. Through this multi-principal element design concept of the sublattice, ordinary binary intermetallic compounds, after being high-entropyized, exhibit superior properties, such as improved ductility and toughness, and more stable high-temperature performance. Based on these characteristics, using high-entropy intermetallic compounds as a transition material at the interface of titanium / steel composite plates, thereby achieving high-entropyization of the original iron-titanium binary compound, shows promising results in solving interfacial bonding problems. Summary of the Invention

[0004] In view of the above-mentioned deficiencies of the prior art, in a first aspect of the present invention, a method for preparing a high-entropy layered transition layer material for titanium-steel bonding, which is simple to process and suitable for industrial production, is provided, comprising the following steps:

[0005] (1) Preprocessing:

[0006] Prepare iron sheets, copper sheets, titanium sheets, and aluminum sheets of uniform size and specifications to obtain metal sheets; remove surface impurities, weigh the corresponding mass of metal sheets according to the equimolar ratio, and randomly stack them together to obtain a laminated blank;

[0007] (2) Rolling process:

[0008] The laminated billet is rolled, and each pass is counted as one rolling pass. After each rolling pass, the laminated billet is folded in half along the rolling direction before the next rolling pass is performed. The above rolling process is repeated until the predetermined number of passes is reached to obtain intermediate material.

[0009] (3) Sealing and compaction:

[0010] The intermediate material is placed inside a metal container, sealed, and compacted to obtain a block material;

[0011] (4) High-temperature hot rolling:

[0012] The bulk material is heat-treated, then hot-rolled and thinned. The heat treatment-hot rolling and thinning process is repeated for a predetermined number of cycles, and finally the high-entropy layered transition layer material for titanium-steel bonding is recovered.

[0013] Preferably, in step (1), the metal sheet includes not only iron sheet, copper sheet, titanium sheet, and aluminum sheet, but also zinc sheet.

[0014] Preferably, in step (2), the rolling is performed at room temperature without lubrication.

[0015] Preferably, in step (2), the reduction in thickness deformation of each rolled laminate is 50% to 70%.

[0016] Preferably, in step (2), the total number of predetermined rolling passes is 40 to 100 passes.

[0017] Preferably, in step (3), the metal receiving element is made of a metal or metal alloy that is easy to process and has good ductility.

[0018] More preferably, the metal receiving element is a cylindrical metal tube that can be closed at both ends; the metal tube is made of copper.

[0019] Preferably, in step (4), the heat treatment is to keep warm at 600-700°C for 30-60 minutes.

[0020] Preferably, in step (4), the number of cycles of heat treatment-hot rolling is 2 to 5.

[0021] Preferably, in step (4), the cumulative reduction in the thickness direction of the block material after heat treatment and hot rolling is 70-90%.

[0022] Due to the significant difference in electronegativity between iron and titanium, they easily form various hard and brittle intermetallic compound phases, making it difficult to achieve good bonding at the interface. However, after introducing other metallic elements, the high-entropy intermetallic compounds have higher mixing entropy, resulting in greater compatibility between the components. The performance differences between iron and this high-entropy layered transition layer material, as well as between titanium and this high-entropy layered transition layer material, are reduced, and their mutual solid solution ability and interfacial bonding ability are enhanced. Applying this material to the transition layer of titanium / steel composite plates can create an alternating layered structure in the entire titanium / steel composite plate material, characterized by large macroscopic layers and small microscopic layers in the transition region.

[0023] The sheet metals are randomly stacked and then rolled multiple times at room temperature without lubrication. During the rolling process, the metal materials undergo intense plastic deformation under pressure, and the interlayer spacing gradually decreases. When the predetermined number of rolling passes is reached, partial solid solution has occurred between the metals. After a period of high-temperature holding, element diffusion is completed, but the layered, non-uniform structure is still maintained. Hot rolling further reduces alloy defects, ultimately yielding a high-entropy layered transition layer material.

[0024] In a second aspect of the invention, a high-entropy layered transition layer material for titanium-steel bonding with a stacked configuration and a large number of heterogeneous interfaces is provided, the material being prepared by the preparation method provided in the first aspect of the invention.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. This invention provides a method for preparing a high-entropy layered transition layer material for titanium-steel bonding. The method is simple, using multi-pass rolling, heat treatment, and hot rolling to obtain the finished product, and is suitable for industrial-scale production. This process does not require liquid solidification to prepare the high-entropy material, thereby avoiding various metallographic defects generated during solidification.

[0027] 2. This invention provides a high-entropy layered transition layer material for titanium-steel bonding. Based on the multi-component characteristics of high-entropy materials, this material has a layered non-uniform structure. Due to the stacked configuration and the presence of a large number of heterogeneous interfaces, this material has superior fracture toughness and hardness compared with the traditional single uniform structure. Attached Figure Description

[0028] Figure 1 This is an optical microscope image of the high-entropy layered transition layer material used for titanium-steel connection in Embodiment 1 of the present invention;

[0029] Figure 2 In the diagram, a to c are scanning electron microscope images of the high-entropy layered transition layer material used for titanium-steel connection in Example 1 of the present invention at different magnifications; d to h are the elemental energy distribution diagrams of its metal elements.

[0030] Figure 3 The X-ray diffraction pattern of the high-entropy layered transition layer material for titanium-steel connection in Embodiment 1 of the present invention is shown below.

[0031] Figure 4 This is an optical microscope image of the intermediate material obtained after rolling treatment in Embodiment 2 of the present invention.

[0032] Figure 5 This is an optical microscope image of the high-entropy layered transition layer material used for titanium-steel connection in Embodiment 2 of the present invention;

[0033] Figure 6 This is the X-ray diffraction pattern of the high-entropy layered transition layer material for titanium-steel connection in Embodiment 2 of the present invention. Detailed Implementation

[0034] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0035] Example 1

[0036] The high-entropy layered transition layer material used for titanium-steel bonding is prepared by the following method:

[0037] (1) Preprocessing:

[0038] Cut iron, copper, titanium, aluminum and zinc sheets with uniform thickness and length and width dimensions of 100mm×50mm. Grind and clean the surface of the metal sheets to remove surface impurities. According to the principle of equimolar ratio, weigh the corresponding mass of iron, copper, titanium, aluminum and zinc sheets and randomly stack the metal sheets together to obtain the laminated blank.

[0039] (2) Rolling process:

[0040] The laminated billet is rolled using an industrial rolling mill under room temperature and no lubrication conditions. Each pass is counted as one rolling pass. After each rolling pass, the laminated billet is folded in half along the rolling direction before the next rolling pass is performed. The thickness deformation of the laminated billet is reduced by 50% in each pass. The above rolling process is repeated up to 100 passes to obtain intermediate material.

[0041] (3) Sealing and compaction:

[0042] One end of a cylindrical copper tube is sealed with a copper sheet, and the intermediate material is placed inside the copper tube. Then, the other end of the copper tube is sealed with a copper sheet. The sealed copper tube containing the intermediate material is placed under a hydraulic press and compacted to obtain a block material. Since the intermediate material is wrapped in a copper layer, high-temperature oxidation of the intermediate material in subsequent operations can be avoided.

[0043] (4) High-temperature hot rolling:

[0044] The bulk material was subjected to four heat treatment-hot rolling and thinning cycles. The bulk material was placed in a muffle furnace. In the first cycle, it was held at 600°C for 30 minutes, and then immediately removed from the muffle furnace and hot rolled and thinned. After thinning, it was placed back into the muffle furnace for the next cycle. In the second and third cycles, it was held at 650°C for 30 minutes, and the hot rolling and thinning operation remained the same. In the fourth cycle, it was held at 700°C for 30 minutes, and the hot rolling and thinning operation remained the same. After four heat treatment-hot rolling and thinning cycles, the cumulative reduction in the thickness direction was 70%. Then, the diffusion region of the alloy and copper tube in the bulk material was removed, and the middle part was recovered to obtain a high-entropy layered transition layer material for titanium-steel bonding, denoted as FeCuTiAlZn.

[0045] The microstructure of the obtained high-entropy layered transition layer material was observed using an optical microscope. Figure 1 It can be seen that after 100 rolling passes and high-temperature hot rolling, the material still maintains its non-uniform layered structure. The microstructure of the obtained high-entropy layered transition layer material was observed using scanning electron microscopy, and the energy spectrum distribution of different elements in the material was determined. Figure 2 Figures a to c show that FeCuAlTi grains have formed in the material, and zinc-rich precipitates are present at the grain boundaries; Figures d to h show that the elements are evenly distributed in the layered structure. Figure 3 The image shows the X-ray diffraction results of a high-entropy layered transition layer material. As shown in the figure, this embodiment yielded a high-entropy intermetallic compound of iron, copper, titanium, and aluminum, with corresponding X-ray diffraction peaks of elemental zinc.

[0046] By combining the energy spectrum distribution images and X-ray diffraction peaks of the elements, it can be found that zinc hardly participates in the formation of high-entropy intermetallic compounds in this alloy, and is instead enriched at the grain boundaries. Here, zinc forms a multiphase structure with the internal grain structure. The zinc precipitated at the grain boundaries has good plasticity and toughness, which optimizes the grain boundary bonding of the alloy.

[0047] The hardness of the alloy was tested using a Magee-H200 microhardness tester with a load of 500g and a holding time of 10s. Ten independent and random points were measured, and the average value was taken. The results showed that the hardness of the FeCuTiAlZn alloy reached 623.8HV.

[0048] Example 2

[0049] The high-entropy layered transition layer material used for titanium-steel bonding is prepared by the following method:

[0050] (1) Preprocessing:

[0051] Cut iron, copper, titanium and aluminum sheets with uniform thickness and length and width dimensions of 100mm×50mm. Grind and clean the surface of the metal sheets to remove surface impurities. According to the principle of equimolar ratio, weigh the corresponding mass of iron, copper, titanium and aluminum sheets and randomly stack them together to obtain the laminated blank.

[0052] (2) Rolling process:

[0053] The laminated billet is rolled using an industrial rolling mill under room temperature and no lubrication conditions. Each pass is counted as one rolling pass. After each rolling pass, the laminated billet is folded in half along the rolling direction before the next rolling pass is performed. The thickness deformation of the laminated billet is reduced by 50% in each pass. The above rolling process is repeated up to 100 passes to obtain intermediate material.

[0054] (3) Sealing and compaction:

[0055] One end of a cylindrical copper tube is sealed with a copper sheet, and the intermediate material is placed inside the copper tube. Then, the other end of the copper tube is sealed with a copper sheet. The sealed copper tube containing the intermediate material is placed under a hydraulic press and compacted to obtain a block material. Since the intermediate material is wrapped in a copper layer, high-temperature oxidation of the intermediate material in subsequent operations can be avoided.

[0056] (4) High-temperature hot rolling:

[0057] The bulk material was subjected to four heat treatment-hot rolling and thinning cycles. The bulk material was placed in a muffle furnace. In the first cycle, it was held at 600°C for 30 minutes, and then immediately removed from the muffle furnace and hot rolled and thinned. After thinning, it was placed back into the muffle furnace for the next cycle. In the second and third cycles, it was held at 650°C for 30 minutes, and the hot rolling and thinning operation remained the same. In the fourth cycle, it was held at 700°C for 30 minutes, and the hot rolling and thinning operation remained the same. After four heat treatment-hot rolling and thinning cycles, the cumulative reduction in the thickness direction was 70%. Then, the diffusion region of the alloy and copper tube in the bulk material was removed, and the middle part was recovered to obtain a high-entropy layered transition layer material for titanium-steel bonding, denoted as FeCuTiAl.

[0058] The microstructure of the intermediate material after rolling and the high-entropy layered transition layer material obtained after high-temperature hot rolling were observed using an optical microscope. Figure 4 It can be seen that after 100 rolling passes, the metal sheets gradually become finer; from Figure 5 It can be seen that the high-entropy layered transition layer material still maintains its non-uniform layered structure. Figure 6 The image shows the X-ray diffraction results of the high-entropy layered transition layer material. A single-phase high-entropy intermetallic compound of iron, copper, titanium, and aluminum was obtained after hot rolling.

[0059] The hardness of the alloy was tested using a Magee-H200 microhardness tester with a load of 100g and a holding time of 10s. Ten independent and random points were measured, and the average value was taken. The results showed that the FeCuTiAl alloy achieved a hardness of 732.5HV.

[0060] Example 3

[0061] The high-entropy layered transition layer material used for titanium-steel bonding is prepared by the following method:

[0062] (1) Preprocessing:

[0063] Cut iron, copper, titanium, aluminum and zinc sheets with uniform thickness and length and width dimensions of 100mm×50mm. Grind and clean the surface of the metal sheets to remove surface impurities. According to the principle of equimolar ratio, weigh the corresponding mass of iron, copper, titanium, aluminum and zinc sheets and randomly stack the metal sheets together to obtain the laminated blank.

[0064] (2) Rolling process:

[0065] The laminated billet is rolled using an industrial rolling mill under room temperature and no lubrication conditions. Each pass is counted as one rolling pass. After each rolling pass, the laminated billet is folded in half along the rolling direction before the next rolling pass is performed. The thickness deformation reduction of the laminated billet in each pass is 70%. The above rolling process is repeated up to 40 passes to obtain intermediate material.

[0066] (3) Sealing and compaction:

[0067] One end of a cylindrical copper tube is sealed with a copper sheet, and the intermediate material is placed inside the copper tube. Then, the other end of the copper tube is sealed with a copper sheet. The sealed copper tube containing the intermediate material is placed under a hydraulic press and compacted to obtain a block material. Since the intermediate material is wrapped in a copper layer, high-temperature oxidation of the intermediate material in subsequent operations can be avoided.

[0068] (4) High-temperature hot rolling:

[0069] The bulk material is subjected to two heat treatment-hot rolling thinning cycles. The bulk material is placed in a muffle furnace, and both cycles are held at 700°C for 30 minutes. The bulk material is then immediately removed from the muffle furnace and hot rolled thin. After thinning, it is placed back into the muffle furnace for the next cycle. After two heat treatment-hot rolling thinning cycles, the cumulative reduction in the thickness direction is 90%. Then, the diffusion region of the alloy and copper tube in the bulk material is removed, and the middle part is recovered to obtain a high-entropy layered transition layer material for titanium-steel bonding.

[0070] Example 4

[0071] The high-entropy layered transition layer material used for titanium-steel bonding is prepared by the following method:

[0072] (1) Preprocessing:

[0073] Cut iron, copper, titanium, aluminum and zinc sheets with uniform thickness and length and width dimensions of 100mm×50mm. Grind and clean the surface of the metal sheets to remove surface impurities. According to the principle of equimolar ratio, weigh the corresponding mass of iron, copper, titanium, aluminum and zinc sheets and randomly stack the metal sheets together to obtain the laminated blank.

[0074] (2) Rolling process:

[0075] The laminated billet is rolled using an industrial rolling mill under room temperature and no lubrication conditions. Each pass is counted as one rolling pass. After each rolling pass, the laminated billet is folded in half along the rolling direction before the next rolling pass is performed. The thickness deformation reduction of the laminated billet in each pass is 70%. The above rolling process is repeated up to 40 passes to obtain intermediate material.

[0076] (3) Sealing and compaction:

[0077] One end of a cylindrical copper tube is sealed with a copper sheet, and the intermediate material is placed inside the copper tube. Then, the other end of the copper tube is sealed with a copper sheet. The sealed copper tube containing the intermediate material is placed under a hydraulic press and compacted to obtain a block material. Since the intermediate material is wrapped in a copper layer, high-temperature oxidation of the intermediate material in subsequent operations can be avoided.

[0078] (4) High-temperature hot rolling:

[0079] The bulk material was subjected to five heat treatment-hot rolling thinning cycles. The bulk material was placed in a muffle furnace, and each of the five cycles was held at 600°C for 60 minutes. The bulk material was then immediately removed from the muffle furnace and hot rolled thin. After thinning, it was placed back into the muffle furnace for the next cycle. After five heat treatment-hot rolling thinning cycles, the cumulative reduction in the thickness direction was 70%. Then, the diffusion region of the alloy and copper tube in the bulk material was removed, and the middle part was recovered to obtain a high-entropy layered transition layer material for titanium-steel bonding.

[0080] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for the production of a high-entropy layered transition layer material for titanium-steel connections, characterized in that The method comprises the following steps: (1) Pretreatment: Prepare iron sheet, copper sheet, titanium sheet and aluminum sheet with uniform size specifications to obtain metal sheets; remove surface impurities, and according to the equal molar proportion, weigh the corresponding mass of the metal sheets, and randomly stack them together to obtain a stacked blank; (2) Rolling treatment: Roll the stacked blank, and record one pass as one rolling; after each pass of rolling, fold the stacked blank along the rolling direction, and then perform the next pass of rolling; repeat the above rolling process until a predetermined number of passes to obtain an intermediate material; The thickness deformation reduction of the stacked blank in each pass of rolling is 50% to 70%; and the total number of predetermined passes of rolling is 40 to 100 passes; (3) Sealing and compaction: Place the intermediate material inside a metal containing member, seal and compact to obtain a bulk material; (4) High-temperature hot rolling: Perform heat treatment on the bulk material, and after heat treatment, perform hot rolling and thinning; repeat the heat treatment-hot rolling and thinning process until a predetermined number of cycles; and finally recover a high-entropy layered transition layer material for titanium-steel connection; The heat treatment is heat preservation at 600 to 700°C for 30 to 60 minutes; the number of cycles of the heat treatment-hot rolling and thinning is 2 to 5 times; and the cumulative reduction of the bulk material in the thickness direction after heat treatment-hot rolling and thinning is 70% to 90%.

2. The method of claim 1, wherein: In step (1), the metal sheets include zinc sheets in addition to iron sheets, copper sheets, titanium sheets and aluminum sheets.

3. The method of claim 1, wherein: In step (3), the metal containing member is made of a metal or metal alloy that is easy to process and has good ductility.

4. The method of claim 3, wherein: The metal containing member is a cylindrical metal tube that can be closed at both ends, and the metal tube is made of copper.

5. A high-entropy layered transition layer material for titanium-steel joining, characterized by: The method is prepared by the preparation method of any one of claims 1-4.

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