Two-pass roll formed high interfacial bond strength metal layered composite and method

Abstract

The application discloses a two-pass rolling forming high-interface bonding strength metal laminated composite and a method, and belongs to the technical field of metal laminated composite preparation. The blank is subjected to softening annealing, and the surface to be compounded is polished. After the blank is stacked, the first-pass rolling is performed, the second-pass rolling is performed, and finally, the short-time diffusion heat treatment is performed, so that the high-interface bonding strength metal laminated composite is obtained. The two-pass rolling forming is adopted, so that the rough surface to be compounded is closely attached, the hardened layer and the oxidized layer at the interface are fully broken and refined, the composite interface with high interface bonding rate is obtained, the synchronous and rapid diffusion of elements on the whole interface is facilitated by the diffusion heat treatment, the uniform diffusion layer is obtained, the generation of the interfacial intermetallic compound is greatly reduced or avoided, the bonding strength of the composite interface is greatly improved, the diffusion heat treatment temperature is significantly reduced, the diffusion heat treatment time is shortened, and the production cycle is short, the cost is low, and the energy is saved, and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal laminated composite material preparation, and particularly relates to a method for forming a high-interface bonding strength metal laminated composite material in two passes. BACKGROUND

[0002] Metal laminated composite materials have the advantages of component metals and excellent comprehensive performance that single metals do not have by combining different metals, and have been widely used in the fields of marine vessels, rail transportation, information communication, aerospace, national defense and military industry, and daily life.

[0003] The interface bonding strength of a metal laminated composite material is one of the most important factors affecting its service performance. The higher the interface bonding strength, the longer the service life of the metal laminated composite material, the higher the safety, and the more extensive the application. Rolling composite is the most commonly used method for large-scale preparation of metal laminated composite materials at present, mainly including hot rolling composite method and cold rolling composite method. Among them, the cold rolling composite method has important position and plays a prominent role in the field of metal laminated composite material preparation technology due to its advantages of direct composite forming in air atmosphere, low oxidation degree of composite interface, and simple process. Since the atomic diffusion ability of metal is low under the condition of lower than recrystallization temperature, only cold rolling composite cannot realize the complete metallurgical bonding of the composite interface of the metal laminated composite material, so diffusion heat treatment is generally required after cold rolling composite to realize complete metallurgical bonding of the composite interface through long-time atomic diffusion at high temperature and obtain high interface bonding strength. However, the traditional cold rolling composite method is usually single-pass large reduction (rolling reduction rate ≥ 60%) rolling composite of the stacked assembly of metal blanks to be compounded. In addition to high requirements for rolling equipment and large investment, there are also some outstanding problems, such as insufficient crushing and refinement of hardened layer and oxidized layer at the composite interface of the formed metal laminated composite blank, insufficient bonding of fresh metal, insufficient tightness of the rough surface to be compounded, easy existence of microcavities at the composite interface, low composite interface bonding rate, and the like. The subsequent diffusion heat treatment requires high temperature and long time, the element diffusion uniformity of the composite interface is not good, the interface bonding quality consistency is poor, a large amount of brittle intermetallic compounds are easily generated, and the interface bonding strength of the prepared metal laminated composite material is low, which seriously restricts the wide application of the cold rolling composite method.

[0004] In view of the above advantages and disadvantages of the traditional single-pass cold rolling composite method, researchers have developed a multi-pass cold rolling composite method.

[0005] The prior art 1 adopts a two-pass rolling composite process to prepare a steel-aluminum composite plate core material, and introduces ultrasonic vibration treatment in the rolling composite process to realize a rolling composite process with small energy consumption. However, due to the addition of the ultrasonic vibration device, the complexity and cost of the equipment and the difficulty of process parameter control are increased; in addition, although the ultrasonic vibration treatment is introduced, due to the too small rolling reduction rate (the highest rolling reduction rate is only 10%) applied in the first-pass rolling composite, the hardening layer and the oxidation layer at the composite interface of the steel plate and the aluminum alloy plate are too little to be broken, the fresh metal is insufficiently exposed and combined, the rough composite surface is insufficiently attached, and the holes existing in the composite interface are too large and too many, so that the bonding rate of the composite interface is very low, thereby resulting in that the bonding quality of the interface after the second-pass rolling composite is still poor, and therefore a high-temperature long-time diffusion heat treatment for 20-24 hours is still required after the rolling composite to obtain the required composite plate core material, which is large in energy consumption, long in time, high in cost, and not low in carbon environmental protection, and a large amount of brittle intermetallic compounds are easily generated at the composite interface to result in that the interface bonding strength of the composite interface is still not high.

[0006] The prior art 2 adopts four-pass asynchronous rolling composite, accumulative super-large reduction deformation is performed, the interface bonding rate of the composite plate composite interface is improved, and only 10-40 minutes of diffusion heat treatment is required after the rolling composite. However, the process is complex, the control is difficult, and four-pass rolling composite is performed, the process flow is long, the energy consumption is large, the production cost is high, the control of the flatness and the uniformity of the coating of the composite interface is not conducive, and in addition, due to the high rolling reduction rate (the lowest rolling reduction rate reaches 55%) applied in the first-pass two-roll composite rough rolling, the rolling equipment investment is large, and at the same time, the work hardening of the rolled composite plate is serious, the residual stress is large, the layer thickness ratio fluctuation is large, and the flatness and the uniformity of the coating of the interface are poor, the above problems will be further aggravated in the subsequent pass rolling composite process, and the temperature difference of the composite interface during the diffusion heat treatment is large, the element diffusion uniformity is poor, and intermetallic compounds are difficult to avoid in the local area, so that it is not easy to obtain high-quality high-performance metal layered composite material with high dimensional accuracy and high interface bonding strength.

[0007] Therefore, it is necessary to develop a new method for cold rolling composite forming of metal layered composite material, reduce the high requirements for cold rolling composite equipment, subsequent diffusion heat treatment temperature and time, improve the interface bonding rate of the metal layered composite material, greatly reduce or avoid the generation of brittle intermetallic compounds at the interface, and ensure that the metal layered composite material with high interface bonding strength is obtained. SUMMARY

[0008] The application aims to provide a two-pass rolling forming high-interface bonding strength metal layered composite material and method, which realizes high-interface bonding rate composite of metal layered composite material interface hardening layer and oxidation layer full broken and refined, fresh metal maximum exposed bonding through two-pass rolling forming, and obtains high-interface bonding strength metal layered composite material through short-time diffusion heat treatment in air atmosphere.

[0009] According to the first aspect of the technical scheme of the application, a method for two-pass rolling forming high-interface bonding strength metal layered composite material is provided, comprising the following steps:

[0010] Step 1: respectively softening annealing the metal blanks to be compounded to obtain the soft metal blanks;

[0011] Step 2: respectively mechanically polishing the surfaces to be compounded of the metal blanks, forming polishing striations perpendicular to the length direction of the metal blanks, then layering the metal blanks to form a metal layered blank, and then first-pass rolling the metal layered blank below the recrystallization temperature of the metal blanks to obtain a metal layered pre-compounded blank, and the rolling reduction rate of the first-pass rolling is 36% to 50%;

[0012] Step 3: second-pass rolling the metal layered pre-compounded blank below the recrystallization temperature of the metal blanks to obtain a metal layered compounded blank, and the rolling reduction rate of the second-pass rolling is greater than or equal to 10%;

[0013] Step 4: short-time diffusion heat treatment of the metal layered compounded blank in air atmosphere, controlling the diffusion heat treatment temperature to be higher than the recrystallization temperature of the low-melting-point component metal of the metal layered compounded blank and lower than the melting point temperature of the low-melting-point component metal, to obtain a high-interface bonding strength metal layered composite material.

[0014] Further, in the step 4, the diffusion heat treatment time is 0.01 to 180 minutes.

[0015] Further, the metal blank is at least one of a wire, a rod, a pipe, a plate, a strip or a profile, which is in a single form, a single block form or a roll form.

[0016] Further, the mechanical polishing is offline mechanical polishing or online mechanical polishing, and the polishing mode is at least one of abrasive belt polishing, abrasive wheel polishing, abrasive wheel polishing, steel wire brush polishing, louver blade polishing or laser polishing.

[0017] Further, the layering is offline layering or online layering.

[0018] Further, the second pass rolling is forward rolling with the head of the metal layered pre-compounded blank entering the roll gap first or reverse rolling with the tail of the metal layered pre-compounded blank entering the roll gap first.

[0019] Further, the diffusion heat treatment is offline heating diffusion heat treatment or online heating diffusion heat treatment, the heating mode is at least one of resistance heating, flame heating, induction heating, pulse heating, radiation heating or laser heating, and the heating atmosphere is at least one of air atmosphere, vacuum, reducing atmosphere or protective atmosphere.

[0020] Further, the metal layered composite material has 2-10 layers.

[0021] Further, the metal is copper, aluminum, magnesium, iron, titanium, nickel, zinc, tin, gold, silver, zirconium, niobium, tantalum, platinum and an alloy of any of the above, or steel, metal composite material.

[0022] According to the second aspect of the technical scheme of the present application, a two-pass rolling forming high interfacial bonding strength metal layered composite material is provided, which is prepared by the method according to any one of the above aspects.

[0023] The present application has the following advantages:

[0024] By using the method, the two-pass rolling forming reduces the pass rolling reduction rate, reduces the high requirements on the cold rolling composite equipment, and fully breaks and refines the hardened layer and the oxidized layer of the composite interface, so as to ensure the composite interface with high interfacial bonding rate, which is beneficial to the subsequent short-time diffusion heat treatment to realize the synchronous rapid diffusion of elements on the entire interface, greatly reduces or avoids the generation of brittle intermetallic compounds, and can accurately control the composition and organizational performance of the composite interface to achieve uniform and consistent interfacial bonding quality, thereby greatly improving the bonding strength of the composite interface; the short-time diffusion heat treatment method has the advantages of shortening the preparation period, saving energy, low carbon and environmental protection, and reducing production cost. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic diagram of the composite interface morphology evolution process during two-pass rolling forming. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in conjunction with the embodiments, and it should be pointed out that the following embodiments are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make non-essential improvements and adjustments according to the content of the present application.

[0027] The technical scheme of the present application provides a two-pass rolling forming high interfacial bonding strength metal layered composite material and method. As shown inFigure 1 As shown, the preparation method includes the following steps:

[0028] Step 1: Soften and anneal the metal billets to be composited separately to obtain soft metal billets.

[0029] The metal billet is, for example, at least one of wire, bar, tube, plate, strip, or profile, and may be in single, single-piece, or coil form. The metal is, for example, copper, aluminum, magnesium, iron, titanium, nickel, zinc, tin, gold, silver, zirconium, niobium, tantalum, platinum, and alloys of any of the above metals, or steel or metal composite materials.

[0030] Step 2: Mechanically grind the surfaces of the metal billets to be composited, with the grinding stripes perpendicular to the length of the metal billets. Then, stack the metal billets to form a layered metal billet. Next, roll the layered metal billet in the first pass below the recrystallization temperature of the metal billet to obtain a layered pre-composite metal billet. The rolling reduction rate of the first pass is 36% to 50%.

[0031] The mechanical grinding can be offline or online, and the grinding method can be at least one of belt grinding, abrasive wheel grinding, grinding wheel grinding, wire brush grinding, louvered grinding, or laser grinding. The laminated preform assembly can be offline or online.

[0032] Step 3: Roll the metal layered pre-composite billet in a second pass below the recrystallization temperature of the metal billet to obtain the metal layered composite billet. The rolling reduction rate of the second pass is ≥10%.

[0033] The second rolling pass is either forward rolling where the head of the metal layered precomposite billet enters the roll gap first, or reverse rolling where the tail of the metal layered precomposite billet enters the roll gap first.

[0034] Step 4: Perform short-time diffusion heat treatment on the metal layered composite billet in an air atmosphere. Control the diffusion heat treatment temperature to be higher than the recrystallization temperature of the low melting point component metal of the metal layered composite billet and lower than the melting point temperature of the low melting point component metal, and the diffusion heat treatment time to be 0.01 to 180 min, to obtain a metal layered composite material with high interfacial bonding strength.

[0035] The diffusion heat treatment can be either offline or online, and the heating method can be at least one of resistance heating, flame heating, induction heating, pulse heating, radiation heating, or laser heating. The heating atmosphere can be at least one of air, vacuum, reducing atmosphere, or protective atmosphere. The number of layers in the metal layered composite material is, for example, 2 to 10 layers.

[0036] The present invention provides a high interfacial bonding strength metal layered composite material prepared by two-pass rolling according to any of the above preparation methods.

[0037] In fact, the applicants of this invention have found that in multi-pass cold rolling composite processes, the rolling reduction rate of the first pass is crucial; it cannot be too small or too large, and should be controlled between 36% and 50%. This is because when the rolling reduction rate of the first pass is small (<35%), it is difficult to break up a large amount of the hardened layer and oxide layer at the composite interface of the metal layered composite billet. Too many large-sized hardened and oxide layers remain at the interface, resulting in insufficient exposure of fresh metal for bonding. Furthermore, the rough surface to be composited has insufficient bonding area, and the composite interface is prone to having a large number of large-sized closed voids. This creates unfavorable conditions for the second pass rolling composite, making it difficult to achieve sufficient breakage and refinement of the hardened and oxide layers, uniform distribution, and a high interface bonding rate through the second pass rolling composite. Conversely, when the rolling reduction rate of the first pass is small (<35%), it is difficult to achieve sufficient exposure and bonding of the fresh metal at the interface, and thus, it is difficult to achieve a high interface bonding rate. When the rolling reduction rate is large (>50%), not only are the requirements for rolling equipment capacity high, but the post-rolled metal layered composite material also suffers from severe work hardening, high residual stress, large fluctuations in layer thickness ratio, and poor interface flatness and coating uniformity. These problems are further exacerbated in subsequent rolling passes, leading to significant temperature differences at the composite interface during diffusion heat treatment, resulting in poor uniformity of element diffusion and making it difficult to avoid the formation of intermetallic compounds in localized areas. Ultimately, it is difficult to obtain high-quality, high-performance metal layered composite materials with high dimensional accuracy and high interfacial bonding strength. Furthermore, the applicant's research has found that in multi-pass cold rolling composite processes, the second rolling pass further breaks down the hardened and oxide layers at the composite interface and improves the bonding rate of the composite interface. Especially when the rolling reduction rate of the first rolling pass is controlled at 36% to 50%, the fresh metal bonding area of ​​the composite interface between the component metals is large, the size and distribution of the hardened layer and oxide layer are reasonable, and the interface does not produce excessive work hardening and uneven deformation. This is more conducive to the full breaking of the hardened layer and oxide layer and the improvement of the composite interface bonding rate during the second rolling pass. When the rolling reduction rate of the second rolling pass is further controlled at ≥10%, the hardened layer and oxide layer of the metal layered composite material interface are fully broken and refined, and the interface achieves a high bonding rate and highly uniform bonding. At this time, there is no need to perform more rolling passes. Meanwhile, under the condition of controlling the rolling reduction rate of the two-pass rolling, the subsequent diffusion heat treatment temperature is further controlled to be higher than the recrystallization temperature of the low-melting-point component metal of the metal layered composite material. Since grain boundaries are fast channels for atomic transport, the continuous high-density grain boundaries generated by using the composite interface as a continuous nucleation site for recrystallized grains can further improve the synchronous diffusion rate of the composite interface with high bonding rate and high uniformity during diffusion heat treatment, shorten the diffusion heat treatment time, and enable precise control of the composition and microstructure properties of the composite interface. This greatly reduces or avoids the formation of brittle intermetallic compounds, achieves uniform interface bonding quality, and thus significantly improves the bonding strength of the composite interface. See the following embodiments and comparative examples for details.

[0038] Example 1:

[0039] Q235 carbon steel / TA2 pure titanium composite plates were prepared using single-sheet Q235 carbon steel strip and TA2 pure titanium strip as raw materials.

[0040] Q235 carbon steel sheet and strip and TA2 pure titanium sheet and strip were softened and annealed respectively to obtain soft Q235 carbon steel sheet and strip and TA2 pure titanium sheet and strip.

[0041] Offline mechanical grinding was performed on the surfaces of Q235 carbon steel strip and TA2 pure titanium strip to be laminated using an angle grinder equipped with louvers to remove contaminants and oxide layers from the surfaces. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the Q235 carbon steel strip and TA2 pure titanium strip.

[0042] Next, the mechanically ground Q235 carbon steel plate and strip billet and TA2 pure titanium plate and strip billet are stacked together to obtain Q235 carbon steel / TA2 pure titanium layered billet.

[0043] Then, the Q235 carbon steel / TA2 pure titanium layered billet is rolled in the first pass with a rolling reduction of 45% to obtain the Q235 carbon steel / TA2 pure titanium pre-composite slab.

[0044] Then, the Q235 carbon steel / TA2 pure titanium pre-composite slab is rolled in a second pass with a rolling reduction rate of 30% to obtain the Q235 carbon steel / TA2 pure titanium composite slab.

[0045] Finally, the Q235 carbon steel / TA2 pure titanium composite slab was placed in a resistance furnace at 700℃ for diffusion heat treatment for 10 minutes to obtain a Q235 carbon steel / TA2 pure titanium composite plate with an interfacial bonding strength of 260±5MPa.

[0046] Example 2:

[0047] A composite plate of TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium was prepared using single-sheet 1050 pure aluminum sheet and strip blanks and TA1 pure titanium sheet and strip blanks as raw materials.

[0048] Softening annealing was performed on 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip respectively to obtain soft 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip.

[0049] Offline mechanical grinding was performed on the surfaces of 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip to be laminated using an angle grinder equipped with grinding wheels to remove contaminants and oxide layers from the surfaces to be laminated. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip.

[0050] Next, the mechanically polished 1050 pure aluminum sheet and strip billet and TA1 pure titanium sheet and strip billet are stacked in the order of TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium to obtain TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet.

[0051] Then, the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet is heated in air at a temperature of 150℃ for 5 minutes. Immediately afterwards, the heated TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet is rolled in the first pass with a rolling reduction rate of 40% to obtain a TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium pre-composite slab.

[0052] Then, the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium pre-composite slab is rolled in a second pass with a rolling reduction rate of 40% to obtain the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite slab.

[0053] Finally, the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite slab was sent into a resistance furnace at 400℃ for diffusion heat treatment for 10 minutes to obtain a TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite plate with an interfacial bonding strength of 90±3MPa.

[0054] Example 3:

[0055] Using 1060 pure aluminum sheet and strip in coil form and Q235 carbon steel sheet and strip in coil form as raw materials, 1060 pure aluminum / Q235 carbon steel composite sheet and strip in coil form is continuously produced.

[0056] Softening annealing was performed on 1060 pure aluminum sheet and strip billets and Q235 carbon steel sheet and strip billets in coil form to obtain soft 1060 pure aluminum sheet and strip billets and Q235 carbon steel sheet and strip billets.

[0057] The 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet were uncoiled using an uncoiling equipment. Then, the surfaces of the 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet to be laminated were mechanically polished online using an online polishing equipment equipped with louvers to remove contaminants and oxide layers from the surfaces to be laminated. The polishing stripes formed by the mechanical polishing were perpendicular to the length direction of the 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet.

[0058] Using an online billet assembly device, mechanically ground 1060 pure aluminum sheet and strip billet and Q235 carbon steel sheet and strip billet are stacked together to obtain 1060 pure aluminum / Q235 carbon steel layered billet.

[0059] The 1060 pure aluminum / Q235 carbon steel layered billet is fed into the rolling mill online for the first pass rolling. The rolling reduction rate of the first pass rolling is 50%, and 1060 pure aluminum / Q235 carbon steel pre-composite plate and strip billet is obtained.

[0060] Next, the 1060 pure aluminum / Q235 carbon steel pre-composite plate and strip billet is fed into the second rolling mill for the second pass rolling. The rolling reduction rate of the second pass rolling is 50%, and the 1060 pure aluminum / Q235 carbon steel composite plate and strip billet is obtained.

[0061] The 1060 pure aluminum / Q235 carbon steel composite plate and strip billet is fed online into a roller hearth furnace at a temperature of 500℃ for diffusion heat treatment for 5 minutes. At the exit of the roller hearth furnace, a coiling device is used to obtain a 1060 pure aluminum / Q235 carbon steel composite plate and strip with an interfacial bonding strength of 82±3MPa in coil form.

[0062] Example 4:

[0063] Using 1060 pure aluminum sheet and strip blanks and T2 pure copper sheet and strip blanks in coil form as raw materials, 1060 pure aluminum / T2 pure copper composite sheet and strip in coil form are continuously prepared.

[0064] Softening annealing was performed on 1060 pure aluminum sheet and strip billets and T2 pure copper sheet and strip billets in coil form to obtain soft 1060 pure aluminum sheet and strip billets and T2 pure copper sheet and strip billets.

[0065] The 1060 pure aluminum sheet and strip blank and the T2 pure copper sheet and strip blank are uncoiled using an uncoiling equipment. Then, the surfaces of the 1060 pure aluminum sheet and strip blank and the T2 pure copper sheet and strip blank to be laminated are mechanically polished online using an online polishing equipment equipped with grinding wheels to remove contaminants and oxide layers from the surfaces to be laminated. The polishing stripes formed by the mechanical polishing are perpendicular to the length direction of the 1060 pure aluminum sheet and strip blank and the T2 pure copper sheet and strip blank.

[0066] Using an online billet assembly device, mechanically polished 1060 pure aluminum sheet and strip billets and T2 pure copper sheet and strip billets are stacked together to obtain 1060 pure aluminum / T2 pure copper layered billets.

[0067] The 1060 pure aluminum / T2 pure copper layered billet is fed into the rolling mill online for the first pass rolling. The rolling reduction rate of the first pass rolling is 36%, and a 1060 pure aluminum / T2 pure copper pre-composite slab is obtained.

[0068] Next, the 1060 pure aluminum / T2 pure copper pre-composite slab is fed into the rolling mill for a second rolling pass. The rolling reduction rate of the second rolling pass is 50%. The 1060 pure aluminum / T2 pure copper composite slab is obtained in coil form using a coiling device.

[0069] Finally, the coiled 1060 pure aluminum / T2 pure copper composite slab is fed into a box-type resistance furnace at 300℃ for diffusion heat treatment for 60 minutes to obtain a coiled 1060 pure aluminum / T2 pure copper composite strip with an interfacial bonding strength of 80±4MPa.

[0070] Example 5:

[0071] T2 pure copper / 316 stainless steel composite plates are prepared using single-sheet T2 pure copper strip blanks and 316 stainless steel strip blanks as raw materials.

[0072] T2 pure copper sheet and strip billet and 316 stainless steel sheet and strip billet were softened and annealed respectively to obtain soft T2 pure copper sheet and strip billet and 316 stainless steel sheet and strip billet.

[0073] Offline mechanical grinding was performed on the surfaces of T2 pure copper strip and 316 stainless steel strip to be laminated using an angle grinder equipped with louvers to remove contaminants and oxide layers from the surfaces. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the T2 pure copper strip and 316 stainless steel strip.

[0074] Next, the mechanically polished T2 pure copper plate and strip billet and the 316 stainless steel plate and strip billet are stacked together to obtain T2 pure copper / 316 stainless steel layered billet.

[0075] Then, the T2 pure copper / 316 stainless steel layered billet is fed into the rolling mill for the first pass rolling. The rolling reduction rate of the first pass rolling is 45%, and T2 pure copper / 316 stainless steel pre-composite slab is obtained.

[0076] Then, the T2 pure copper / 316 stainless steel pre-composite slab is fed into the rolling mill for a second rolling pass. The rolling reduction rate of the second rolling pass is 30%, and the T2 pure copper / 316 stainless steel composite slab is obtained.

[0077] Finally, the T2 pure copper / 316 stainless steel composite slab was placed in a resistance furnace at 800℃ for diffusion heat treatment for 10 minutes to obtain a T2 pure copper / 316 stainless steel composite plate with an interfacial bonding strength of 220±7MPa.

[0078] Example 6:

[0079] 304 stainless steel / TA2 pure titanium composite plates were prepared using single-sheet 304 stainless steel strip blanks and TA2 pure titanium strip blanks as raw materials.

[0080] Softening annealing was performed on 304 stainless steel sheet and strip blanks and TA2 pure titanium sheet and strip blanks respectively to obtain soft 304 stainless steel sheet and strip blanks and TA2 pure titanium sheet and strip blanks.

[0081] Offline mechanical grinding was performed on the surfaces of 304 stainless steel strip and TA2 pure titanium strip to be laminated using an angle grinder equipped with grinding wheels to remove contaminants and oxide layers from the surfaces to be laminated. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the 304 stainless steel strip and TA2 pure titanium strip.

[0082] Next, the mechanically polished 304 stainless steel sheet and strip billet and TA2 pure titanium sheet and strip billet are stacked together to obtain 304 stainless steel / TA2 pure titanium layered billet.

[0083] Then, the 304 stainless steel / TA2 pure titanium layered billet is rolled in the first pass with a rolling reduction of 45% to obtain a 304 stainless steel / TA2 pure titanium pre-composite slab.

[0084] Then, the 304 stainless steel / TA2 pure titanium pre-composite slab is rolled in a second pass with a rolling reduction rate of 50% to obtain the 304 stainless steel / TA2 pure titanium composite slab.

[0085] Finally, the 304 stainless steel / TA2 pure titanium composite slab was placed in a resistance furnace at 800℃ for diffusion heat treatment for 5 minutes to obtain a 304 stainless steel / TA2 pure titanium composite plate with an interfacial bonding strength of 270±8MPa.

[0086] Comparative Example 1:

[0087] Compared with Example 1, Q235 carbon steel strip and TA2 pure titanium strip were used as raw materials to prepare Q235 carbon steel / TA2 pure titanium composite plate.

[0088] Q235 carbon steel sheet and strip and TA2 pure titanium sheet and strip were softened and annealed respectively to obtain soft Q235 carbon steel sheet and strip and TA2 pure titanium sheet and strip.

[0089] Offline mechanical grinding was performed on the surfaces of Q235 carbon steel strip and TA2 pure titanium strip to be laminated using an angle grinder equipped with louvers to remove contaminants and oxide layers from the surfaces. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the Q235 carbon steel strip and TA2 pure titanium strip.

[0090] Next, the mechanically ground Q235 carbon steel plate and strip billet and TA2 pure titanium plate and strip billet are stacked together to obtain Q235 carbon steel / TA2 pure titanium layered billet.

[0091] Then, the Q235 carbon steel / TA2 pure titanium layered billet was rolled in a single pass with a reduction rate of 62%, which is consistent with the total reduction rate of the two-pass rolling in Example 1, to obtain the Q235 carbon steel / TA2 pure titanium pre-composite slab.

[0092] Finally, the Q235 carbon steel / TA2 pure titanium composite slab was placed in a resistance furnace at 700℃ for diffusion heat treatment for 10 minutes. The interfacial bonding strength of the obtained Q235 carbon steel / TA2 pure titanium composite plate was 180±50MPa. Due to the use of single-pass high-reduction rolling, the hardened layer and oxide layer at the composite interface were unevenly and insufficiently broken. Furthermore, the temperature and time of the diffusion heat treatment were lower and shorter than those of the traditional method, making the problem of uneven and insufficient interfacial bonding more prominent. Therefore, the interfacial bonding strength of the obtained Q235 carbon steel / TA2 pure titanium composite plate was low and fluctuated significantly.

[0093] Comparative Example 2:

[0094] Compared with Example 2, a TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite plate was prepared by using single-sheet 1050 pure aluminum sheet and strip blanks and TA1 pure titanium sheet and strip blanks as raw materials.

[0095] Softening annealing was performed on 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip respectively to obtain soft 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip.

[0096] Offline mechanical grinding was performed on the surfaces of 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip to be laminated using an angle grinder equipped with grinding wheels to remove contaminants and oxide layers from the surfaces to be laminated. The grinding stripes formed by the mechanical grinding were perpendicular to the length direction of the 1050 pure aluminum sheet and strip and TA1 pure titanium sheet and strip.

[0097] Next, the mechanically polished 1050 pure aluminum sheet and strip billet and TA1 pure titanium sheet and strip billet are stacked in the order of TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium to obtain TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet.

[0098] Then, the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet is heated in air at a temperature of 150°C for 5 minutes. Immediately afterwards, the heated TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium layered billet is rolled in the first pass with a rolling reduction rate of 15% to obtain a TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium pre-composite slab.

[0099] The TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium pre-composite slab is then subjected to a second rolling pass with a rolling reduction of 58%. The total rolling reduction of the two passes is consistent with that of the two passes in Example 2, thus obtaining the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite slab.

[0100] Finally, the TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite slab was placed in a resistance furnace at 400℃ for diffusion heat treatment for 10 minutes, resulting in an interfacial bonding strength of 60±21MPa. Due to the low rolling reduction in the first rolling pass, too many large-sized hardened and oxide layers existed at the interface, and the interface was prone to having numerous large-sized closed pores. Furthermore, it was difficult to achieve sufficient breaking of the hardened and oxide layers and complete closure of the pores during the second rolling pass. Additionally, the temperature and time of the subsequent diffusion heat treatment were lower and shorter than traditional methods. Therefore, the interfacial bonding strength of the obtained TA1 pure titanium / 1050 pure aluminum / TA1 pure titanium composite slab was low and fluctuated significantly.

[0101] Comparative Example 3:

[0102] Compared with Example 3, 1060 pure aluminum sheet and strip in coil form and Q235 carbon steel sheet and strip in coil form were used as raw materials to continuously prepare 1060 pure aluminum / Q235 carbon steel composite sheet and strip in coil form.

[0103] Softening annealing was performed on 1060 pure aluminum sheet and strip billets and Q235 carbon steel sheet and strip billets in coil form to obtain soft 1060 pure aluminum sheet and strip billets and Q235 carbon steel sheet and strip billets.

[0104] The 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet were uncoiled using an uncoiling equipment. Then, the surfaces of the 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet to be laminated were mechanically polished online using an online polishing equipment equipped with louvers to remove contaminants and oxide layers from the surfaces to be laminated. The polishing stripes formed by the mechanical polishing were perpendicular to the length direction of the 1060 pure aluminum sheet and strip billet and the Q235 carbon steel sheet and strip billet.

[0105] Using an online billet assembly device, mechanically ground 1060 pure aluminum sheet and strip billet and Q235 carbon steel sheet and strip billet are stacked together to obtain 1060 pure aluminum / Q235 carbon steel layered billet.

[0106] The 1060 pure aluminum / Q235 carbon steel layered billet is fed into the rolling mill online for the first pass rolling. The rolling reduction rate of the first pass rolling is 60%, and 1060 pure aluminum / Q235 carbon steel pre-composite plate and strip billet is obtained.

[0107] Next, the 1060 pure aluminum / Q235 carbon steel pre-composite plate and strip billet is fed into the second rolling mill for the second pass rolling. The rolling reduction rate of the second pass rolling is 38%. The total rolling reduction rate of the two passes rolling is consistent with the total rolling reduction rate of the two passes rolling in Example 3, and 1060 pure aluminum / Q235 carbon steel composite plate and strip billet is obtained.

[0108] 1060 pure aluminum / Q235 carbon steel composite strip billets were fed online into a roller hearth furnace at 500℃ for diffusion heat treatment for 5 minutes. At the roller hearth furnace exit, a coiling device was used to obtain 1060 pure aluminum / Q235 carbon steel composite strips in coil form. The interfacial bonding strength of the composite strip was 55±17MPa, while the thickness of the component layers fluctuated significantly. Due to the excessive rolling reduction in the first rolling pass, severe local work hardening occurred at the interface, resulting in high residual stress, large fluctuations in the layer thickness ratio, and poor straightness and uniformity of the interface. These problems were further exacerbated during the second rolling pass. During diffusion heat treatment, the interface diffusion consistency was poor, and thicker brittle intermetallic compounds even formed at some local interfaces. Therefore, the obtained 1060 pure aluminum / Q235 carbon steel composite strips had low interfacial bonding strength, poor bonding consistency, and significant fluctuations in the thickness of the component layers.

[0109] The above are merely specific embodiments of the present invention, but the protection of the present invention is not limited thereto. Any equivalent variations or substitutions of the features of the present technical solution that can be conceived by those skilled in the art are covered within the protection scope of the present invention. The protection scope of the present invention should be determined by the scope of the claims.

Claims

1. A method for forming a high-interfacial-bonding-strength metal layered composite material through two-pass rolling, characterized in that, The method achieves a high interfacial bonding rate composite material by fully breaking down and refining the interface hardened layer and oxide layer of the metal layered composite material through two-pass rolling forming, and by maximizing the exposure of fresh metal for bonding. Furthermore, a metal layered composite material with high interfacial bonding strength is obtained by short-time diffusion heat treatment in an air atmosphere. The method includes the following steps: Step 1: Perform softening annealing on the metal billets to be composited to obtain the soft metal billets; Step 2: The surfaces of the metal billets to be composited are mechanically polished, with the polishing stripes perpendicular to the length of the metal billets. The metal billets are then stacked to form a layered metal billet. The layered metal billet is then rolled in the first pass below the recrystallization temperature of the metal billet to obtain a layered pre-composite metal billet. The rolling reduction rate of the first pass is 36% to 50%. Step 3: The metal layered pre-composite billet is rolled in a second pass below the recrystallization temperature of the metal billet to obtain a metal layered composite billet. The rolling reduction rate of the second pass is ≥10%. Step 4: The metal layered composite billet is subjected to short-time diffusion heat treatment in an air atmosphere. The diffusion heat treatment temperature is controlled to be higher than the recrystallization temperature of the low melting point component metal of the metal layered composite billet and lower than the melting point temperature of the low melting point component metal, so as to obtain a metal layered composite material with high interfacial bonding strength. In step 4, the diffusion heat treatment time is 0.01 to 10 minutes.

2. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The metal billet is at least one of wire, bar, tube, plate, strip or profile, and is in the form of a single piece, a single block or a roll.

3. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The mechanical polishing is either offline or online, and the polishing method is at least one of belt polishing, abrasive wheel polishing, grinding wheel polishing, wire brush polishing, louver polishing, or laser polishing.

4. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The stacked blanks can be offline stacked blanks or online stacked blanks.

5. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The second rolling pass is either forward rolling where the head of the metal layered precomposite billet enters the roll gap first, or reverse rolling where the tail of the metal layered precomposite billet enters the roll gap first.

6. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The diffusion heat treatment is either offline or online, and the heating method is at least one of resistance heating, flame heating, induction heating, pulse heating, radiation heating, or laser heating.

7. The method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The number of layers in the metal layered composite material is 2 to 10.

8. A method for forming a high interfacial bonding strength metal layered composite material by two-pass rolling as described in claim 1, characterized in that, The metal is copper, aluminum, magnesium, iron, titanium, nickel, zinc, tin, gold, silver, zirconium, niobium, tantalum, platinum, or an alloy of any of the above metals, or steel or metal composite materials.

9. A two-pass rolled high-interfacial-bonding-strength metal layered composite material, characterized in that, The high interfacial bonding strength metal layered composite material formed by two rolling passes is prepared by the method according to any one of claims 1 to 8.

Images