Method for forming intelligent metal by integrating metal and polymer flexible sensors

Abstract

The present application discloses a method for forming an intelligent metal by integrating metal and polymer flexible sensors using ultrasonic consolidation additive manufacturing, wherein the steps are to place the polymer flexible sensor on an 1100 aluminum strip, and to cover it in sequence with a pure copper strip with a groove 5% to 15% larger than the sensor and a complete 1100 aluminum strip, and finally to use ultrasonic consolidation additive manufacturing to consolidate the metal and polymer flexible sensors, so that the polymer flexible sensor is consolidated into the metal matrix. The present invention adopts the preparation technology of ultrasonic consolidation additive manufacturing, and the working temperature is much lower than the traditional welding method. It can complete the embedding of the polymer flexible sensor while ensuring the integrity of the sensor and the metal matrix material. It is a method for forming an intelligent metal material by integrating metal and polymer flexible sensors.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic additive manufacturing, and in particular relates to a method for manufacturing intelligent metal materials by integrating metal and polymer flexible sensors using ultrasonic consolidation additive manufacturing. Background Art

[0002] Most of the existing intelligent metal structure preparation technologies use high temperature and deposition methods to consolidate sensors into metal matrices to manufacture intelligent metals. The temperature during the consolidation process usually exceeds the Curie point of typical piezoelectric materials, resulting in the destruction or degradation of their sensing performance. In addition, the higher consolidation process temperature may also damage related electronic components and wire protection layers. In order to avoid the influence of high temperature on the sensor, epoxy resin or silicone resin mixture can be used as a bonding medium to bond the sensor to the metal for bonding and fixing. Although this method avoids the influence of high temperature, it takes a long time for the bonding medium to cure, and the additional bonding medium layer between the sensor and the metal matrix will also affect the response of the sensor.

[0003] In order to solve the above problems, ultrasonic consolidation additive manufacturing is introduced. It uses metal strips as the matrix, generates energy through high-power ultrasonic vibration, and produces metallurgical bonding between the strips to achieve laminated manufacturing of metal strips. The forming temperature of ultrasonic consolidation additive manufacturing is low, the forming speed is fast, and no gas protection is required. Therefore, ultrasonic consolidation additive manufacturing can effectively realize the integrated forming of flexible sensors and metal substrates. Summary of the invention

[0004] The present invention provides a method for forming intelligent metal by integrating metal and polymer flexible sensors using ultrasonic consolidation additive manufacturing. The method uses ultrasonic consolidation additive manufacturing to achieve consolidation of a metal matrix and a polymer flexible sensor.

[0005] The preparation method of smart metal materials is as follows:

[0006] A method for integrally forming a metal and polymer flexible sensor comprises the following steps:

[0007] S1. A groove is formed on one side or both sides of the copper strip, and a polymer flexible sensor is placed in the groove to obtain a sandwich layer;

[0008] S2. Aluminum strips are respectively attached to the upper and lower surfaces of the sandwich layer, and the sandwich layer and the aluminum strip are consolidated and formed by an ultrasonic consolidation additive manufacturing method to obtain a smart metal strip embedded with a polymer flexible sensor.

[0009] Preferably, the width of the groove is 5% to 15% greater than the width of the polymer flexible sensor, and the depth of the groove is 80% to 110% of the thickness of the polymer flexible sensor. The width of the groove is slightly greater than the width of the sensor, which not only allows the sensor to be conveniently placed in the groove before consolidation, but also during consolidation, the elastic polymer on the surface of the flexible sensor is squeezed and deformed, so that the surface of the flexible sensor can be effectively attached to each inner wall of the groove, and the redundant groove space can buffer the deformation caused by extrusion. At the same time, the reaction force of the elastic polymer after deformation can also effectively clamp and fix the sensor, and the copper strip and the aluminum strip can be fully attached to the flexible sensor through the deformed elastic polymer, thereby improving the response accuracy of the sensor.

[0010] Preferably, the aluminum strip is 1100 aluminum strip, and the copper strip is pure copper strip. The reason why the sandwich layer is made of pure copper strip is that the hardness of copper is higher than that of aluminum. During the ultrasonic consolidation process, the two layers of aluminum strip will squeeze the sandwich layer. The copper strip with higher hardness will have a smaller deformation after being squeezed, and the groove deformation will also be smaller, which effectively prevents the polymer flexible sensor from protruding from the groove. If the sandwich layer is made of aluminum, the groove will be deformed more during ultrasonic consolidation, and the polymer flexible sensor will easily protrude from the groove. After consolidation, the position of the sensor will change, making it difficult to respond effectively. Moreover, the protruding sensor surface is difficult to fit smoothly with the aluminum strip and the copper strip, further affecting the sensitivity and accuracy of the sensor.

[0011] Preferably, the aluminum strips bonded to the upper and lower surfaces of the sandwich layer have the same size, and the width of the pure copper strip is the same as that of the 1100 aluminum strip.

[0012] Preferably, the width of the 1100 aluminum strip is 1.5 to 3.5 times the maximum width of the polymer flexible sensor, and the thickness of the 1100 aluminum strip is 4 to 6 times the thickness of the polymer flexible sensor; the thickness of the pure copper strip is 2 to 3 times the maximum thickness of the polymer flexible sensor. The thickness and width of the strip should not be too small. Too small size will lead to increased deformation during consolidation, affecting the consolidation of the sensor in the matrix, while too large thickness and width will directly affect the responsiveness of the sensor.

[0013] Preferably, the ultrasonic consolidation additive manufacturing method uses an ultrasonic consolidation additive manufacturing system to weld and consolidate the aluminum strip and the copper strip.

[0014] Preferably, the processing parameters of the ultrasonic consolidation additive manufacturing system are:

[0015] The welding speed control range of the ultrasonic consolidation additive manufacturing system is 20 mm / s to 30 mm / s;

[0016] The preheating temperature of the ultrasonic consolidation additive manufacturing system is 25°C to 110°C;

[0017] The positive pressure of the ultrasonic consolidation additive manufacturing system is 90kgf to 130kgf;

[0018] The amplitude of the ultrasonic consolidation additive manufacturing system is 20 μm to 30 μm.

[0019] Preferably, the method further comprises a strip pretreatment step: the surface of the copper strip is cleaned with an organic solvent before and after the grooves are formed, and the surface of the aluminum strip is cleaned with an organic solvent before processing.

[0020] A smart metal strip is prepared by the above method, comprising two layers of aluminum strips respectively fixed to the upper and lower surfaces of a layer of copper strip, a polymer flexible sensor is clamped and fixed between the copper strip and the aluminum strip, the surface of the polymer flexible sensor is covered with an elastic polymer, and the polymer flexible sensor is extruded and bonded to the copper strip and the aluminum strip through the elastic polymer.

[0021] Advantages of the present invention:

[0022] (1) The present invention realizes the consolidation of polymer flexible sensors and metal substrates through ultrasonic consolidation additive manufacturing. This preparation method avoids the limitations of traditional processes such as low degree of freedom design and high temperature that easily leads to sensor damage. At the same time, the degree of bonding is good, and it can be used as a common means of ultrasonic consolidation additive manufacturing to integrate metal and polymer flexible sensors into intelligent metal.

[0023] (2) The present invention realizes the consolidation of the polymer flexible sensor and the metal substrate through ultrasonic consolidation additive manufacturing, and the sensor responds well to changes in external conditions, indicating that the consolidation of the sensor and the metal substrate achieved by ultrasonic consolidation additive manufacturing will not damage the sensor, and effectively realizes the integrated forming of the sensor and the technical substrate.

[0024] (3) Consolidating sensors in a metal matrix allows for better proximity to the physical process they monitor and structural protection of it. In addition, ultrasonic additive manufacturing for smart metal manufacturing also provides design freedom to optimize sensor location, achieve functionality, and reduce manufacturing constraints. Therefore, ultrasonic additive manufacturing methods are a practical means to achieve integrated forming of sensors and metals to obtain smart metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 Schematic diagram of ultrasonic consolidation additive manufacturing with embedded sensors after testing.

[0027] Figure 2 Plot of the sensor’s resistance change with temperature before embedding for ultrasonic consolidation additive manufacturing.

[0028] Figure 3 Resistance change of the sensor with temperature after embedding by ultrasonic consolidation additive manufacturing.

[0029] Figure 4 It is a schematic diagram of the cross-sectional structure of the smart metal material; wherein, 1-upper aluminum strip, 11-lower aluminum strip, 2-copper strip, 3-groove, 4-polymer flexible temperature sensor. DETAILED DESCRIPTION

[0030] The specific implementation methods of the present application are described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0031] Example 1: Ultrasonic consolidation additive manufacturing of metal and polymer flexible sensors integrated into smart metal:

[0032] The first step is to clean and pretreat the surfaces of the copper strip and the aluminum strip. The surfaces of the strips are cleaned with anhydrous ethanol having an alcohol content of not less than 99.7% to remove oil stains on the surfaces of the strips and prevent the pollutants from affecting the bonding quality of the strips.

[0033] In the second step, the strips are 1100 aluminum strip and pure copper strip. The width of the 1100 aluminum strip is 1.5 times the maximum width of the polymer flexible sensor, and the thickness of the 1100 aluminum strip is 4 times the thickness of the polymer flexible sensor; the thickness of the pure copper strip is 2 times the maximum thickness of the polymer flexible sensor. The width of the pure copper strip is the same as that of the 1100 aluminum strip. The two aluminum strips above and below the copper strip are the same size.

[0034] The third step is to use a CNC machine tool to process grooves 5% larger than the sensor width on the edges of both sides of the pure copper strip according to the size of the flexible sensor used. The depth of the groove is 80% of the thickness of the polymer flexible sensor. After the grooving process is completed, the surface of the copper strip is cleaned again with an organic solvent.

[0035] The fourth step is to place the slotted copper strip on the 1100 aluminum strip with the slot facing upwards, then place the sensor into the slot, and cover the copper strip and the sensor with another 1100 aluminum strip. After the strip edges are aligned, the copper strip and the aluminum strip are welded using an ultrasonic consolidation additive manufacturing system. After welding, the polymer flexible temperature sensor is squeezed and clamped between the copper strip and the aluminum strip, and the polymer flexible temperature sensor is clamped and fixed in the slot, so that the polymer flexible temperature sensor is consolidated with the metal matrix, thereby obtaining an intelligent metal material with sensing function, and its structure is as follows: Figure 4 As shown. The specific ultrasonic consolidation parameters used in the ultrasonic consolidation additive manufacturing system are an amplitude of 20μm, a speed of 20mm / s, a positive pressure of 90kgf, and a preheating temperature of 25°C. The sensor used is a polymer flexible temperature sensor with a size of 10mm×10mm×50μm. The surface of the polymer flexible temperature sensor is covered with an elastic polymer, and the polymer flexible temperature sensor relies on the elastic deformation of the elastic polymer layer to extrude and fit with the copper strip and the aluminum strip, so that the flexible temperature sensor is clamped and consolidated between the two layers of metal substrates.

[0036] Example 2: Ultrasonic consolidation additive manufacturing of metal and polymer flexible sensors integrated to form smart metal:

[0037] In the first step, the surfaces of the copper strip and the aluminum strip are cleaned and pretreated. The surfaces of the strips are cleaned with acetone to remove oil stains on the surfaces of the strips and prevent pollutants from affecting the bonding quality of the strips.

[0038] In the second step, the strips are 1100 aluminum strip and pure copper strip. The width of the 1100 aluminum strip is 3.5 times the maximum width of the polymer flexible sensor, and the thickness of the 1100 aluminum strip is 6 times the thickness of the polymer flexible sensor; the thickness of the pure copper strip is 3 times the maximum thickness of the polymer flexible sensor. The width of the pure copper strip is the same as the width of the 1100 aluminum strip. The two aluminum strips above and below the copper strip are the same size. The sizes of the two aluminum strips can also be adjusted to be different as needed. When the sizes of the two aluminum strips are different, the width of the copper strip is the same as the width of the narrower 1100 aluminum strip.

[0039] In the third step, according to the size of the flexible sensor used, a CNC machine tool is used to process grooves 15% larger than the sensor width on the edges of both sides of the pure copper strip. The depth of the groove is 110% of the thickness of the polymer flexible sensor. After the grooving process is completed, the surface of the copper strip is cleaned again with an organic solvent.

[0040] The fourth step is to place the slotted copper strip on the 1100 aluminum strip with the groove facing up, then put the sensor into the groove, and cover the copper strip and the sensor with another 1100 aluminum strip. Finally, the copper strip and the aluminum strip are welded using an ultrasonic consolidation additive manufacturing system. After welding, the polymer flexible temperature sensor is squeezed and clamped between the copper strip and the aluminum strip, and the polymer flexible temperature sensor is clamped and fixed in the groove, so that the polymer flexible temperature sensor is consolidated with the metal matrix, thereby obtaining an intelligent metal material with sensing function. The specific ultrasonic consolidation parameters used in the ultrasonic consolidation additive manufacturing system are an amplitude of 30μm, a speed of 30mm / s, a positive pressure of 130kgf, and a preheating temperature of 110℃. The sensor used is a polymer flexible temperature sensor with a size of 20mm×20mm×100μm.

[0041] Example 3: Ultrasonic consolidation additive manufacturing of metal and polymer flexible sensors to form smart metal:

[0042] The first step is to clean and pretreat the surfaces of the copper strip and the aluminum strip. The surfaces of the strips are cleaned with anhydrous ethanol having an alcohol content of not less than 99.7% to remove oil stains on the surfaces of the strips and prevent the pollutants from affecting the bonding quality of the strips.

[0043] In the second step, the strips are 1100 aluminum strip and pure copper strip. The width of the 1100 aluminum strip is 2.5 times the maximum width of the polymer flexible sensor, and the thickness of the 1100 aluminum strip is 5 times the thickness of the polymer flexible sensor; the thickness of the pure copper strip is 2.5 times the maximum thickness of the polymer flexible sensor. The width of the pure copper strip is the same as that of the 1100 aluminum strip. The two aluminum strips above and below the copper strip are the same size.

[0044] The third step is to use a CNC machine tool to process a groove 10% larger than the sensor width on the single side edge of the pure copper strip according to the size of the flexible sensor used. The depth of the groove is 90% of the thickness of the polymer flexible sensor. After the grooving process is completed, the surface of the copper strip is cleaned again with an organic solvent.

[0045] The fourth step is to place the slotted copper strip on the 1100 aluminum strip with the groove facing up, then put the sensor into the groove, and cover the copper strip and the sensor with another 1100 aluminum strip. Finally, the copper strip and the aluminum strip are welded using an ultrasonic consolidation additive manufacturing system. After welding, the polymer flexible temperature sensor is squeezed and clamped between the copper strip and the aluminum strip, and the polymer flexible temperature sensor is clamped and fixed in the groove, so that the polymer flexible temperature sensor is consolidated with the metal matrix, thereby obtaining an intelligent metal material with sensing function. The specific ultrasonic consolidation parameters used in the ultrasonic consolidation additive manufacturing system are an amplitude of 25μm, a speed of 25mm / s, a positive pressure of 110kgf, and a preheating temperature of 75℃. The sensor used is a polymer flexible temperature sensor with a size of 10mm×10mm×50μm.

[0046] The performance of the intelligent metal material prepared in Example 1 is tested in the following way: the intelligent metal is attached to the curved surface of the columnar metal, and the columnar metal is placed on a heating plate. During the test, the heating plate acts as a heat source to provide different ambient temperatures to the columnar metal. The resistance of the intelligent metal attached to the surface of the columnar metal will change under different temperature environments, and the data acquisition device will measure the resistance of the sensor in real time. At the same time, the infrared camera will also measure the temperature of the columnar metal near the position where the intelligent metal is measured, and finally the resistance-temperature relationship is measured as a discrete series. The test device is as follows: Figure 1 shown.

[0047] Test results such as Figure 2 and Figure 3 As shown, after the polymer flexible temperature sensor is embedded in the metal matrix, its responsiveness to temperature is basically the same as before embedding, which indicates that the sensor can respond well and perform functions after being solidified with the metal matrix, making the composite metal material have the ability of intelligent response.

[0048] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A method for integrally forming a metal and polymer flexible sensor, characterized in that: The steps include: S1. A groove is formed on one side or both sides of the copper strip, and a polymer flexible sensor is placed in the groove to obtain a sandwich layer; S2, laminating aluminum strips on the upper surface and the lower surface of the sandwich layer respectively, and consolidating the sandwich layer and the aluminum strips by using an ultrasonic consolidation additive manufacturing method to obtain a smart metal strip embedded with a polymer flexible sensor; The width of the groove is 5% to 15% greater than the width of the polymer flexible sensor, and the depth of the groove is 80% to 110% of the thickness of the polymer flexible sensor; the aluminum strip is 1100 aluminum strip, and the copper strip is pure copper strip; the width of the 1100 aluminum strip is 1.5 to 3.5 times the maximum width of the polymer flexible sensor, and the thickness of the 1100 aluminum strip is 4 to 6 times the thickness of the polymer flexible sensor; the thickness of the pure copper strip is 2 to 3 times the maximum thickness of the polymer flexible sensor; the aluminum strips bonded to the upper and lower surfaces of the sandwich layer have the same size, and the width of the pure copper strip is the same as the width of the 1100 aluminum strip; The processing parameters of the ultrasonic consolidation additive manufacturing system are: The welding speed control range of the ultrasonic consolidation additive manufacturing system is 20 mm / s to 30 mm / s; The preheating temperature of the ultrasonic consolidation additive manufacturing system is 25°C to 110°C; The positive pressure of the ultrasonic consolidation additive manufacturing system is 90kgf to 130kgf; The amplitude of the ultrasonic consolidation additive manufacturing system is 20 μm to 30 μm.

2. The method for integrated forming of metal and polymer flexible sensors according to claim 1, characterized in that: The ultrasonic consolidation additive manufacturing method uses an ultrasonic consolidation additive manufacturing system to weld and consolidate aluminum strips and copper strips.

3. The method for integrated forming of metal and polymer flexible sensors according to claim 1, characterized in that: The copper strip is cleaned on the surface with an organic solvent before and after the grooves are formed, and the aluminum strip is cleaned on the surface with an organic solvent before processing.

4. A smart metal strip, characterized in that: The smart metal strip is made by the method described in any one of claims 1 to 3, and includes two layers of aluminum strips respectively fixed to the upper and lower surfaces of a layer of copper strip, a polymer flexible sensor is clamped and fixed between the copper strip and the aluminum strip, the surface of the polymer flexible sensor is covered with an elastic polymer, and the polymer flexible sensor is extruded and bonded to the copper strip and the aluminum strip through the elastic polymer.

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