Preparation method of continuous C f / Al composite material based on laser cladding

Abstract

The present invention discloses a preparation method of continuous C f / Al composite materials, which is specifically implemented according to the following steps: establishing a sample model of C f / Al composite materials by using finite element software, and performing simulation calculations on the temperature field and stress field of laser cladding of the sample under different process parameters to determine the preparation process parameters; pre-treating the surface of carbon fiber bundles by nickel plating to form a nickel plating layer with a thickness of 0.3 μm to 0.4 μm on the fiber surface, and obtaining nickel-plated carbon fiber bundles; laying the nickel-plated carbon fiber bundles on the surface of an aluminum substrate, and then obtaining a substrate with carbon fiber bundles through laser cladding according to the preparation process parameters; repeating step 3 to lay 7 to 9 layers from bottom to top on the surface of the substrate with carbon fiber bundles to obtain continuous C f / Al composite materials; the present invention helps to improve the mechanical properties of aluminum matrix composite materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation methods of metal matrix composites, and particularly relates to a preparation method of continuous C f / Al composites based on laser cladding. Background Art

[0002] In today's era, the development of industrial composite materials has become the mainstream and an inevitable trend in current academic research. Among them, continuous carbon fiber reinforced metal matrix composites (CFRMMCs) have received extensive attention due to their excellent properties and broad prospects in engineering applications. In recent years, a large number of studies have been carried out in the field of continuous carbon fiber reinforced metal matrix composites, including continuous carbon fiber reinforced aluminum matrix, magnesium matrix, and copper matrix metal matrix composites. Among them, the research on this type of composite material with aluminum as the matrix has progressed rapidly and achieved remarkable results, with wide applications and great market demand. Aluminum is light in weight, low in density, and has many advantages, while continuous C f / Al composites use continuous carbon fiber tows as the reinforcement, and combine their characteristics such as high temperature resistance, excellent fatigue resistance, low thermal expansion, low density and high strength, and high modulus with the aluminum matrix, thereby improving the comprehensive mechanical properties and dimensional stability under extreme conditions of the composite material. Since continuous carbon fibers have both high strength and toughness compared with short carbon fibers, and the fiber tows are the main load-bearing components, the service performance of the matrix material under complex working conditions is effectively improved. Therefore, continuous C f / Al composites have high strength and modulus in the fiber direction. At present, continuous C f / Al composites have been widely used in many industrial fields, especially in the aerospace and automotive industries, such as the production of engine pistons, propeller blades, aircraft rockets and other components.

[0003] At present, the main preparation methods of continuous C f / Al composites mainly include the coating combined with hot isostatic pressing method, pressure infiltration method, and powder metallurgy method.

[0004] The coating combined with hot isostatic pressing method deposits or coats the metal matrix material on the surface of the fiber reinforcement by physical vapor deposition (PVD) or electron beam evaporation deposition (EBED), and then uses hot isostatic pressing or hot pressing to combine high temperature and high pressure. The combination of the aluminum matrix and the fiber reinforcement is achieved by transmitting pressure through high-pressure inert gas in a sealed container. Although this process can prepare relatively dense continuous C f / Al composites, it has high requirements for material forming, a single structure, and a long preparation cycle; the pressure infiltration method pours the aluminum matrix melt under inert gas or vacuum protection into the prefabricated continuous carbon fiber reinforcement, and under the action of pressure, the aluminum melt infiltrates into the gaps between the carbon fiber tows to achieve the composite effect. This process is used to prepare continuous C fThe technology on the / Al composite material is mature and the operation is simple, but the equipment requirements are relatively complex. When preparing large parts, it takes a long time and has low efficiency, and the operability for preparing some composite materials with structural requirements is relatively low; the powder metallurgy method is used for the preparation of particulate or whisker C f / Al reinforced composite materials is relatively common. Under gas protection, after prefabricating continuous carbon fiber tows, a large amount of metal powder is coated on the surface and melted at high temperature to obtain continuous C f / Al composite materials. However, due to the influence of no external pressure and material layer thickness, the composite materials prepared by this method have poor effects in terms of density and the combination of the inner matrix and the reinforcement

[0005] In summary, there is no method in the prior art to prepare continuous C f / Al composite materials through laser cladding additive manufacturing technology, achieving a short process cycle, simple process flow, and improving mechanical properties Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing continuous C f / Al composite materials based on laser cladding, which has the characteristic of improving the mechanical properties of the composite materials

[0007] The technical solution of the present invention is that the method for preparing continuous C f / Al composite materials based on laser cladding is specifically implemented according to the following steps: Step 1: Use finite element software to establish a sample model of C f / Al composite materials, and perform simulation calculations on the temperature field and stress field of laser cladding of the sample under different process parameters to determine the preparation process parameters

[0008] Step 2: Perform nickel plating pretreatment on the surface of the carbon fiber tow to form a nickel plating layer with a thickness of 0.3μm - 0.4μm on the fiber surface, and obtain the nickel-plated carbon fiber tow

[0009] Step 3: Lay the nickel-plated carbon fiber tow on the surface of the aluminum substrate, and then obtain a substrate with carbon fiber tow through laser cladding according to the preparation process parameters

[0010] Step 4: Repeat Step 3 and lay 7 - 9 layers from bottom to top on the surface of the substrate with carbon fiber tow to obtain continuous C f / Al composite materials

[0011] The characteristics of the present invention also lie in that the preparation process parameters in Step 1 include laser power, scanning speed, spot radius, layer thickness, single-pass width, and fiber coating

[0012] The laser power is 700W - 800W, the scanning speed is 2mm / s - 3mm / s, the layer thickness is 0.5mm - 1mm, the spot radius is 2.9mm - 3mm, the single pass width is 3mm - 4mm, and the fiber coating is nickel.

[0013] Step 2 is specifically implemented according to the following steps:

[0014] Step 2.1: Select a T700 carbon fiber tow with a single filament diameter of 6.9μm - 7.0μm;

[0015] Step 2.2: Subject the surface of the carbon fiber tow to surface degumming treatment in a KSL-1700X heat treatment furnace at a temperature of 400°C - 450°C for a time of 5min - 8min, and then perform water washing to obtain a degummed carbon fiber tow;

[0016] Step 2.3: At room temperature, immerse the degummed carbon fiber tow in a strong acid solution with a ratio of water to strong acid of (2 - 3):7 for 25min - 30min for surface roughening, and then perform water washing to obtain a roughened carbon fiber tow; the strong acid is HNO3 or H2SO4;

[0017] Step 2.4: Perform electroplating nickel treatment on the surface of the roughened carbon fiber tow to form a nickel plating layer with a thickness of 0.3μm - 0.4μm on the fiber surface, and obtain a carbon fiber tow after nickel plating treatment.

[0018] The current density of the electroplating nickel treatment in Step 2.4 is 0.39A / dm 2 ~0.4A / dm 2 , the main salt in the nickel salt plating solution for electroplating nickel treatment is NiSO4, the buffer is boric acid, the anti-passivation agent is nickel chloride, the dispersant is sodium dodecyl sulfate, and the electroplating nickel treatment time is 8min - 12min.

[0019] In the nickel salt plating solution for electroplating nickel treatment, NiSO4 is 270g / L - 275g / L, boric acid is 40g / L - 45g / L, nickel chloride is 70g / L - 75g / L, and sodium dodecyl sulfate is 0.1g / L - 0.15g / L.

[0020] Step 3 is specifically implemented according to the following steps:

[0021] Step 3.1: Select argon as the protective gas, and clad 1 - 2 layers of aluminum on a special aluminum substrate as a primer to obtain an aluminum substrate;

[0022] Step 3.2: Cut the carbon fiber tow after nickel plating treatment to a length of 100mm - 110mm, and lay it in the same direction as the cladding and clamp it on the surface of the aluminum substrate to obtain a clamped carbon fiber tow;

[0023] Step 3.3: Determine and set the laser power, scanning speed, spot radius, layer thickness, and single-pass width, and perform laser cladding on the clamped carbon fiber tow until the aluminum metal powder and the fiber are uniformly infiltrated and completely melted and solidified to obtain a substrate with carbon fiber tows.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. By performing nickel plating modification treatment on the surface of continuous carbon fibers, the present invention enables the reinforcing fibers to be well wetted with the metal during the laser cladding process, obtaining good interfacial bonding and also maintaining the excellent mechanical properties of the continuous fibers to the greatest extent.

[0026] 2. By laying the filaments in the same direction as the cladding direction, the present invention can make the continuous fibers evenly distributed in the cladding layer and can also adjust the density of the carbon fiber filament laying according to the reinforcement requirements, which helps to improve the mechanical properties of the aluminum matrix composite.

[0027] 3. The laser additive manufacturing technology adopted by the present invention uses a high-power laser to prepare products with fine grain structures and excellent composite properties, and the mechanical properties in various aspects such as hardness and tensile strength are improved. Description of the Drawings

[0028] Figure 1 is the flow chart of the preparation method of continuous C f / Al composite materials based on laser cladding;

[0029] Figure 2 is the SEM image of the carbon fiber tow without treatment in the preparation method of the present invention;

[0030] Figure 3 is the SEM image of the carbon fiber tow after nickel plating treatment in the preparation method of the present invention;

[0031] Figure 4 is the metallographic microscope observation image of the carbon fiber tow after nickel plating treatment in the preparation method of the present invention;

[0032] Figure 5 is the SEM image of the interfacial bonding of the carbon fiber tow without treatment in the preparation method of the present invention;

[0033] Figure 6 is the SEM image of the interfacial bonding of the carbon fiber tow after nickel plating treatment in the preparation method of the present invention;

[0034] Figure 7 is the SEM image of the tensile fracture surface of the carbon fiber tow after nickel plating treatment in the preparation method of the present invention;

[0035] Figure 8 is the microscopic morphology observation image of Example 2 of the preparation method of the present invention;

[0036] Figure 9 It is the microscopic morphology observation diagram of Example 3 of the preparation method of the present invention;

[0037] Figure 10 It is the SEM diagram of the interface combination between the carbon fiber tow and the matrix in Example 2 of the preparation method of the present invention;

[0038] Figure 11 It is the SEM diagram of the interface combination between the carbon fiber tow and the matrix in Example 3 of the preparation method of the present invention;

[0039] Figure 12 It is the EDS surface scan analysis diagram of Example 2 of the preparation method of the present invention;

[0040] Figure 13 It is the EDS surface scan analysis diagram of Example 3 of the preparation method of the present invention. Detailed implementation manners

[0041] The present invention will be described in detail below in conjunction with the drawings and specific implementation manners.

[0042] The preparation method of the continuous C f / Al composite material based on laser cladding of the present invention is as Figure 1 shown, and is specifically implemented according to the following steps:

[0043] Step 1: Use finite element software to establish a sample model of the C f / Al composite material, and perform simulation calculations on the temperature field and stress field during the laser cladding process of the sample under different process parameters to determine the preparation process parameters; after analysis, the preparation process parameters are obtained as follows: including laser power, scanning speed, spot radius, layer thickness, single-pass width, and fiber coating layer. Among them, the laser power is 700W - 800W, the scanning speed is 2mm / s - 3mm / s, the layer thickness is 0.5mm - 1mm, the spot radius is 2.9mm - 3mm, the single-pass width is 3mm - 4mm, and the fiber coating layer is nickel. Corresponding analysis and research are carried out on the calculation results to achieve the purpose of initially optimizing the process theoretical data.

[0044] Step 2: Perform nickel plating pretreatment on the surface of the carbon fiber tow to form a nickel plating layer with a thickness of 0.3μm - 0.4μm on the fiber surface, and obtain the nickel-plated carbon fiber tow; to improve the wettability with the aluminum matrix and protect the carbon fiber.

[0045] As Figure 2 shown, Step 2.1: Select a T700 carbon fiber tow with a single fiber diameter of 6.9μm - 7.0μm;

[0046] Step 2.2: Subject the surface of the carbon fiber tow to surface degumming treatment in a KSL-1700X heat treatment furnace at a temperature of 400°C to 450°C for 5 minutes to 8 minutes, and then wash it with water to obtain a degummed carbon fiber tow;

[0047] Step 2.3: At room temperature, immerse the degummed carbon fiber tow in a strong acid solution with a ratio of water to strong acid of (2 - 3):7 for 25 minutes to 30 minutes for surface roughening, and then wash it with water to obtain a roughened carbon fiber tow; the strong acid is HNO3 or H2SO4;

[0048] As Figure 3 shown, Step 2.4: Electroplate the surface of the roughened carbon fiber tow to form a nickel plating layer with a thickness of 0.3μm to 0.4μm on the fiber surface to obtain a nickel-plated carbon fiber tow; the current density of the electroplating nickel treatment is 0.39A / dm 2 ~0.4A / dm 2 , the main salt in the nickel salt plating solution for the electroplating nickel treatment is NiSO4, the buffer is boric acid, the anti-passivation agent is nickel chloride, the dispersant is sodium dodecyl sulfate, and the electroplating nickel treatment time is 8 minutes to 12 minutes; in the nickel salt plating solution for the electroplating nickel treatment, NiSO4 is 270g / L - 275g / L, boric acid is 40g / L - 45g / L, nickel chloride is 70g / L - 75g / L, and sodium dodecyl sulfate is 0.1g / L - 0.15g / L.

[0049] Through a series of surface nickel plating modification treatments on continuous carbon fibers, the reinforcing fibers can be well wetted with the metal during the laser cladding process, obtaining good interfacial bonding, and can also maintain the good mechanical properties of the continuous fibers themselves to the greatest extent.

[0050] Step 3: Lay the nickel-plated carbon fiber tow on the surface of the aluminum substrate, and then obtain a substrate with carbon fiber tow through laser cladding according to the preparation process parameters;

[0051] Step 3.1: Select argon as the protective gas, and clad 1 - 2 layers of aluminum on a special aluminum substrate as a base to obtain an aluminum substrate;

[0052] Step 3.2: Cut the nickel-plated carbon fiber tow to a length of 100mm to 110mm and lay it on the surface of the aluminum substrate in the same direction as the cladding and clamp it to obtain a clamped carbon fiber tow; by laying the wire in the same direction as the cladding direction, the continuous fibers can be evenly distributed in the cladding layer, and the density of the carbon fiber wire laying can also be adjusted according to the reinforcement requirements, which helps to improve the mechanical properties of the aluminum matrix composite.

[0053] Step 3.3: Determine and set the laser power, scanning speed, spot radius, layer thickness, and single-pass width, and perform laser cladding on the clamped carbon fiber tow until the aluminum metal powder and the fiber are uniformly infiltrated and completely melted. Wait for it to solidify to obtain a substrate with carbon fiber tows. Since the laser additive manufacturing technology used is the LMD laser cladding technology, the finished product prepared by its high-power laser has fine crystal grains and excellent composite properties, and the mechanical properties in terms of hardness, tensile strength, etc. are all improved.

[0054] Step 4: Repeat Step 3 and lay 7 to 9 layers from bottom to top on the surface of the substrate with carbon fiber tows to obtain continuous C f / Al composite material. The continuous C f / Al composite material sample prepared by this method has good mechanical properties. The tensile and flexural strengths are 72.41 MPa and 122.1 MPa, respectively, which are 13.44% and 13.6% higher than those of the pure aluminum cladding sample.

[0055] As Figure 4 shown, through the observation of the cross-sectional morphology of the continuous C f / / Al composite material sample with a nickel-plated layer prepared by this method under a metallurgical microscope, as Figure 6 shown, in the SEM image of the interface bonding, it can be seen that the morphology of the carbon fiber is complete and well-preserved, without cracking damage, and it has a good combination with the aluminum matrix. A large number of white precipitates are formed around the carbon fiber and are closely combined with the aluminum matrix, and there are not many defects at the interface; as Figure 5 shown, in the SEM image of the interface bonding of the non-nickel-plated continuous C f / Al composite material, it can be seen that the interface bonding is poor. Although the single fiber has been basically filled with the aluminum matrix, the interface crack is large and the combination is not tight.

[0056] Example 1

[0057] This example provides a preparation method of continuous C f / Al composite material based on laser cladding. The specific steps are as follows:

[0058] Step 1: Use finite element software to establish a C f / Al composite material sample model, and perform simulation calculations on the temperature field and stress field of the laser cladding of the sample under different process parameters to determine the preparation process parameters;

[0059] Step 2: Perform nickel plating pretreatment on the surface of the carbon fiber tow to form a nickel-plated layer with a thickness of 0.3 μm to 0.4 μm on the fiber surface to obtain a nickel-plated carbon fiber tow;

[0060] Step 3: Lay the nickel-plated carbon fiber tow on the surface of the aluminum substrate, and then obtain the substrate with carbon fiber tow through laser cladding according to the preparation process parameters; among them, the process parameters are laser power 750W, spot radius 3mm, scanning speed 2mm / s, layer thickness 1mm, and single pass width 4mm.

[0061] Step 4: Repeat Step 3 to lay 7 - 9 layers from bottom to top on the surface of the substrate with carbon fiber tow in sequence to obtain continuous C f / Al composite material. As Figure 7 shown, SEM image of the tensile fracture surface of the continuous C f / Al composite material sample with nickel-plated layer. Mechanical property tests were carried out on the cladded composite material sample, and the tensile and flexural strengths were 72.41MPa and 122.1MPa respectively, showing increases of 13.44% and 13.6% respectively compared with the pure aluminum cladded sample, but the density decreased due to the addition of carbon fiber tow.

[0062] Example 2

[0063] This example provides a preparation method of continuous C f / Al composite material based on laser cladding. The difference from Example 1 is that the process parameters are laser power 700W, spot radius 3mm, scanning speed 2mm / s, layer thickness 0.5mm, and single pass width 4mm. As Figure 8 shown, its microscopic morphology, as Figure 10 shown, SEM image of the fiber-to-carbon fiber and matrix interface bonding. Through EDS area scan analysis, it is found that a large amount of nickel-aluminum metal compounds are formed around the carbon fiber reinforcement, as Figure 12 shown, and the mechanical tensile property test result has increased by 8.06%.

[0064] Example 3

[0065] This example provides a preparation method of continuous C f / Al composite material based on laser cladding. The difference from Example 1 is that the process parameters are laser power 750W, spot radius 3mm, scanning speed 2mm / s, layer thickness 0.5mm, and single pass width 4mm. As Figure 9 shown, its microscopic morphology, as Figure 11 shown, SEM image of the fiber-to-carbon fiber and matrix interface bonding. Through EDS area scan analysis, it is found that a large amount of nickel-aluminum metal compounds are formed around the carbon fiber reinforcement, as Figure 13 shown, and the mechanical tensile property test result has increased by 13.44%.

Claims

1. Preparation method of continuous C f / Al composite material by laser cladding, characterized in that The implementation is specifically carried out according to the following steps: Step 1: Use finite element software to establish a C f / Al composite sample model, and perform simulation calculations on the temperature field and stress field of laser cladding of the sample under different process parameters to determine the preparation process parameters; Step 2: Perform nickel plating pretreatment on the surface of the carbon fiber tow to form a nickel plating layer with a thickness of 0.3 μm to 0.4 μm on the fiber surface, obtaining a nickel-plated carbon fiber tow; Step 3: Lay the nickel-plated carbon fiber tow on the surface of the aluminum substrate, and then through laser cladding according to the preparation process parameters, obtain a substrate with carbon fiber tows; Step 4: Repeat Step 3 to lay 7 to 9 layers from bottom to top on the surface of the substrate with carbon fiber tows to obtain a continuous C f / Al composite material; The specific implementation of Step 2 is as follows: Step 2.1: Select a T700 carbon fiber tow with a single fiber diameter of 6.9 μm to 7.0 μm; Step 2.2: Subject the surface of the carbon fiber tow to surface degumming treatment in a KSL-1700X heat treatment furnace at a temperature of 400 °C to 450 °C for 5 min to 8 min, and then perform water washing to obtain a degummed carbon fiber tow; Step 2.3: At room temperature, immerse the degummed carbon fiber tow in a strong acid solution with a ratio of water to strong acid of (2 - 3):7 for 25 min to 30 min for surface roughening, and then perform water washing to obtain a roughened carbon fiber tow; the strong acid is HNO3 or H2SO4; Step 2.4: Perform electroplating nickel treatment on the surface of the roughened carbon fiber tow to form a nickel plating layer with a thickness of 0.3 μm to 0.4 μm on the fiber surface, obtaining a nickel-plated carbon fiber tow; The preparation process parameters in Step 1 include laser power, scanning speed, spot radius, layer thickness, single-pass width, and fiber plating layer; The laser power is 700 W to 800 W, the scanning speed is 2 mm / s to 3 mm / s, the layer thickness is 0.5 mm to 1 mm, the spot radius is 2.9 mm to 3 mm, the single-pass width is 3 mm to 4 mm, and the fiber plating layer is nickel; The current density for the electroplating nickel treatment in Step 2.4 is 0.39 A / dm 2 ~0.4 A / dm 2 , the main salt in the nickel salt plating solution for the electroplating nickel treatment is NiSO4, the buffer is boric acid, the passivation inhibitor is nickel chloride, the dispersant is sodium dodecyl sulfate, and the electroplating nickel treatment time is 8 min to 12 min; In the nickel salt plating solution for the electroplating nickel treatment, NiSO4 is 270 g / L - 275 g / L, boric acid is 40 g / L - 45 g / L, nickel chloride is 70 g / L - 75 g / L, and sodium dodecyl sulfate is 0.1 g / L - 0.15 g / L; The specific implementation of Step 3 is as follows: Step 3.1: Select argon as the protective gas, and clad 1 to 2 layers of aluminum layer on a special aluminum substrate as a primer to obtain an aluminum substrate; Step 3.2: Cut the nickel-plated carbon fiber tow to a length of 100 mm to 110 mm, and lay it on the surface of the aluminum substrate in the same direction as the cladding and clamp it to obtain a clamped carbon fiber tow; Step 3.3: Determine and set the laser power, scanning speed, spot radius, layer thickness, and single-pass width, and perform laser cladding on the clamped carbon fiber tow until the aluminum metal powder and the fiber are evenly infiltrated and completely melted and solidified to obtain a substrate with carbon fiber tows.

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