Aluminum alloy extrusion forming production process

Abstract

The invention discloses an aluminum alloy extrusion forming production process, which relates to the technical field of extrusion production, and comprises the following steps: designing an extrusion die, carrying out surface heat treatment on the extrusion die, selecting an aluminum alloy material, heating and extruding, carrying out surface treatment processing on a produced aluminum alloy profile, and packaging the aluminum alloy profile after the aluminum alloy profile is inspected to be qualified. Compared with the prior art, the method has the advantages that the grain structure of the profile can be more uniform and refined by accurately regulating and controlling the complex relation among parameters such as the extrusion temperature, the mold temperature, the extrusion speed and the lubricating condition, so that the mechanical property is enhanced, like a 6063 aluminum alloy profile, the tensile strength can be improved, the yield strength is improved, deformation or damage in the using process is effectively avoided, and meanwhile, the service life of the profile is prolonged. Good parameter matching can effectively reduce internal defects of the profile, metal can flow in a mold more smoothly, internal pores, cracks and other defects caused by non-uniform metal flow are reduced, and the surface quality is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of extrusion production, in particular to an aluminum alloy extrusion molding production process. Background Art

[0002] Aluminum alloy extrusion molding is a metal processing method. Its principle is to put the aluminum alloy billet into the extrusion cylinder, and under the action of strong pressure, make the billet pass through the die hole of the die to obtain the desired shape and size of the product, just like squeezing toothpaste out of a toothpaste tube, except that here huge pressure is used to make the aluminum alloy material pass through the die hole of a specific shape. This process mainly relies on the pressure provided by the extruder. The pressure of the extruder generally ranges from hundreds of tons to tens of thousands of tons. The pressure causes the aluminum alloy to produce plastic deformation. Aluminum alloy building profiles are one of the important application areas of aluminum alloy extrusion molding. Modern buildings pursue beauty, energy saving and versatility. Aluminum alloy extrusion profiles can be easily processed into various shapes, such as window frames, curtain wall frames, etc. Its good corrosion resistance can ensure that the building components are not affected by the harsh environment during long-term use, and the recyclability of aluminum alloys is also in line with the sustainable development concept of the construction industry.

[0003] The extrusion production of aluminum alloy profiles is a complex process, involving the control of multiple process parameters, such as extrusion temperature, extrusion speed, die temperature, lubrication conditions, etc. These process parameters affect each other and are difficult to optimize. Therefore, we propose an aluminum alloy extrusion molding production process. Summary of the invention

[0004] The purpose of the present invention is to provide an aluminum alloy extrusion molding production process.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: an aluminum alloy extrusion molding production process, including designing an extrusion die, performing surface heat treatment on the extrusion die, selecting an aluminum alloy material for heating and extrusion, performing surface treatment processing on the produced aluminum alloy profile, and packaging after inspection. The specific steps of the aluminum alloy extrusion molding production process are as follows:

[0006] Step 1: Design and material selection: design a suitable mold according to product requirements, select the appropriate mold steel material, and cut the mold steel material into the required blank size;

[0007] Step 2: Perform preliminary forging on the mold blank, use a milling machine to perform rough processing on the mold blank, then heat treat the mold blank, and then use a CNC machine tool to perform fine processing on the mold;

[0008] Step 3: Carry out surface treatment on the processed mold, assemble the various parts of the mold, and conduct a comprehensive quality inspection on the mold before putting it into production;

[0009] Step 4: placing the aluminum alloy blank heated to a certain temperature in the extrusion barrel of the extruder, preheating the mold, applying pressure through the extrusion rod to make the aluminum alloy blank pass through the mold cavity, putting lubricant between the aluminum alloy blank and the mold during extrusion, and extruding a profile of a desired shape;

[0010] Step 5: heat-treat the extruded profile, and then cool, straighten, cut and surface treat it;

[0011] Step 6: Conduct quality inspection on the finished profiles, including size inspection, surface quality inspection and mechanical property inspection. After passing the inspection, the aluminum alloy profiles are packaged.

[0012] As a further solution of the present invention: in the step one, the mold steel material is cut into the required blank size, the material of the mold is selected as tungsten-molybdenum alloy, the mold composition structure includes a mold base, a mold core, a diverter hole, a welding chamber, a working belt, a feed port, a cooling system and an exhaust groove, the extrusion ratio of the mold is set to 5-20, the dimensional tolerance of the mold is less than ±0.05mm, the number of diverter holes is set to 6-10, and they are symmetrically distributed, the size of the diverter holes is selected to be 5mm-20mm, the angle of the diverter holes is set to 30°-60°, the length of the working belt is set to 4mm-8mm, and the working belt is designed with transition fillets at different cross-section changes. The radius of the transition fillet is set to 0.5mm-2mm, the depth of the exhaust groove is set to 0.05mm-0.2mm, and the width is set to 3mm-8mm.

[0013] As a further solution of the present invention: in the step 2, the tungsten-molybdenum alloy is heated to 1400°C-1600°C by induction heating for 30min-60min, the heated tungsten-molybdenum alloy is forged by a friction press, the forging speed is set to 10mm / s-30mm / s, the forging pressure is set to 150MPa-300MPa, the forging ratio is 3-8, after forging, the tungsten-molybdenum alloy is placed in a heating furnace, slowly cooled with the furnace, and the cooled tungsten-molybdenum alloy is placed in a milling machine for rough machining, the tool uses a cemented carbide tool coated with a titanium nitride layer, the cutting speed is set to 30m / min-60m / min, the feed rate is set to 0.1mm / r-0.3mm / r, and the cutting depth is set The cutting fluid is 1mm-5mm, and cutting fluid is used for cooling and lubrication during cutting. The cutting fluid is emulsion, and the flow rate of the emulsion is set to 10L / min-20L / min. The tungsten-molybdenum alloy after rough machining is put into the heating furnace again for annealing. The annealing temperature is set to 1000℃-1400℃, and the insulation is 1h-3h. After annealing, furnace cooling is adopted, and the cooling rate is set to 10℃ / h-20℃ / h. After cooling, the tungsten-molybdenum alloy is placed in a CNC machine tool for fine machining. The tool material is polycrystalline cubic boron nitride, the cutting speed is set to 80m / min-120m / min, the feed rate is set to 0.05mm / r-0.15mm / r, and the cutting depth is set to 0.1mm-0.5mm.

[0014] As a further scheme of the present invention: in the step three, a cleaning agent is used to clean the oil stains on the surface of each part of the processed tungsten-molybdenum alloy mold, and acetone is selected as the cleaning agent. After cleaning, the tungsten-molybdenum alloy mold is placed in a polishing machine for polishing. During rough polishing, a polishing paste with a particle size between 80-120 meshes is selected, and the abrasive of the polishing paste is selected from silicon carbide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 1200r / min-1500r / min. During fine polishing, a polishing paste with a particle size between 320-600 meshes is selected, and the abrasive of the polishing paste is selected from cerium oxide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 800r / min-1000r / min. Before assembly, a micrometer is used to measure the size of the mold, and the appearance of the mold parts is detected to see if there are bumps and scratches. After assembly, a trial mold is performed to observe the appearance quality of the trial mold product, including flash, material shortage and shrinkage defects, and the dimensional accuracy of the trial mold product is measured and compared with the design product size.

[0015] As a further solution of the present invention: in the step 4, the model of the aluminum alloy billet is 6063 aluminum alloy, and the aluminum alloy billet is heated by an induction heating furnace to 520°C-580°C. The mold is preheated by an external heating device before extrusion, and the preheating temperature is set to 400°C-500°C. During extrusion, the extrusion force of the extrusion rod is set to 100MPa-500MPa, and the extrusion speed is controlled to 5mm / s-20mm / s. During extrusion, a lubricant is used to act between the aluminum alloy and the mold, and the lubricant is glass powder. The amount of glass powder is 1%-3% of the weight of the aluminum alloy billet. The lubricating channel around the die hole of the mold injects the lubricant into the space between the aluminum alloy and the mold during the extrusion process, and the aluminum alloy billet passes through the mold cavity to extrude a profile of a required shape.

[0016] As a further scheme of the present invention: in the step five, the extruded aluminum alloy profile enters an air circulation heating furnace for insulation treatment, the temperature of the air circulation heating furnace is set to 520℃-580℃, and the insulation is 30min-60min. The aluminum alloy profile after insulation is cooled in a mist cooling device, the diameter of the water mist particles is 10um-50um, the water mist temperature is set to 10℃-30℃, the mist cooling flow rate is set to 5L / min-20L / min, the pressure is set to 0.2MPa-0.5MPa, the movement speed of the profile is set to 0.1m / s-0.3m / s, and the mist cooling time is 30s-120s. The cooled aluminum alloy profile then enters a straightening device for straightening treatment.

[0017] As a further solution of the present invention: In the step 5, the aluminum alloy profile is straightened using a hydraulic press, and the section modulus of the aluminum alloy profile is first calculated, and the formula is:

[0018]

[0019] Among them, W represents the section modulus of the aluminum alloy profile, b represents the width of the aluminum alloy profile, h represents the height of the aluminum alloy profile, and 6 represents the mathematical coefficient determined by the geometric characteristics of the rectangular cross section and the definition of the section modulus. The straightening pressure is calculated based on the section modulus of the aluminum alloy profile. The calculation formula is:

[0020] P=σW

[0021] Among them, P represents the straightening pressure, σ represents the allowable bending stress, and the allowable bending stress is 50MPa-100MPa. The hydraulic press can straighten the aluminum alloy profile according to the calculated straightening pressure.

[0022] As a further solution of the present invention: in the step 5, a fully automatic saw is used to cut the straightened aluminum alloy profile, a bevel tooth saw blade is selected, the number of teeth is selected to be 120-180 teeth, the diameter is 250mm-400mm, the sawing speed is set to 30000mm / min-60000mm / min, and the feed rate is set to 0.05-0.15mm / tooth, the aluminum alloy profile can be cut into a required length, and an alkaline solution is used to clean the surface of the cut aluminum alloy profile. The alkaline cleaning agent uses a sodium hydroxide solution with a mass fraction of 3%-5%, and the aluminum profile is immersed in it for 10min-15min, the temperature is maintained at 50℃-60℃, and then rinsed with clean water, the aluminum alloy profile is placed in an electrolyte, and a DC power supply is connected. Under the action of the electric field, aluminum atoms lose electrons on the anode surface to form Al 3+ , Al 3+ Reacts with anions in the electrolyte to form an oxide film on the surface of the aluminum profile. The electrolyte is 15%-20% sulfuric acid by mass, and the current density is set to 1A / dm 2 -2A / dm 2 , the voltage is set to 12V-20V, and an oxide film is generated on the surface of the aluminum alloy profile, and the thickness of the oxide film is between 5um-20um.

[0023] As a further solution of the present invention: in the step six, a three-coordinate measuring instrument is used to measure the size of the produced aluminum alloy profile, and the dimensional tolerance is set between ±0.3mm. The surface of the aluminum alloy profile is directly observed by naked eyes to check whether there are obvious defects, including scratches, abrasions, pits, bubbles and cracks. The roughness of the profile surface is measured using a roughness meter, and the arithmetic mean roughness of the profile surface is 0.2um-0.8um. ​​The thickness of the oxide film on the surface of the profile is measured using a film thickness meter, and the thickness of the anodized film is between 5um-20um. A universal testing machine is used to perform a tensile test on the profile, and a hardness tester is used to measure the hardness of the profile. After passing the inspection, a suitable packaging material is selected according to the size, shape and transportation requirements of the profile. The packaging material uses a wooden packaging box, and the box is filled with foam plastic. The name, specification, quantity, production date and manufacturer's information of the profile must be indicated on the package.

[0024] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The present invention can make the grain structure of the profile more uniform and refined by accurately controlling the complex relationship between parameters such as extrusion temperature, die temperature, extrusion speed and lubrication conditions, thereby enhancing the mechanical properties. For example, the tensile strength of 6063 aluminum alloy profiles can be improved, and the yield strength can be improved, effectively avoiding deformation or damage during use. At the same time, good parameter matching can effectively reduce the defects inside the profile, make the metal flow in the die smoother, reduce the internal pores, cracks and other defects caused by uneven metal flow, improve the appearance quality of the profile, and better meet the strict requirements of the fields of construction, machinery and other fields on product quality;

[0026] 2. After the present invention successfully optimizes these mutually influential process parameters, preheating the mold can increase the mold temperature. When the aluminum alloy billet enters the mold, the temperature difference between the billet and the mold is reduced, which can reduce the cooling rate of the billet, so that the aluminum alloy maintains good plasticity at a higher temperature and is easier to flow, thereby better filling the mold cavity, avoiding defects such as cold shut and increased surface roughness caused by sudden temperature changes on the profile surface, and improving the surface quality of the profile. After extrusion, the internal structure of the aluminum alloy profile is in an unstable state. Through heat preservation, the profile can be properly adjusted at high temperature, such as promoting the uniformity of the recrystallization process. There are certain stress and deformation structures inside the aluminum alloy after extrusion. Heat preservation can allow atoms to have enough time to rearrange and make the structure more uniform, thereby stabilizing the mechanical properties of the profile, such as improving the uniformity of strength and toughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the aluminum alloy extrusion molding production steps in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] The present invention discloses an aluminum alloy extrusion molding production process, which includes designing an extrusion die, performing surface heat treatment on the extrusion die, selecting an aluminum alloy material for heating and extrusion, performing surface treatment processing on the aluminum alloy profile after production, and packaging after inspection. The specific steps of the aluminum alloy extrusion molding production process are as follows:

[0030] Step 1: Design and material selection: design a suitable mold according to product requirements, select the appropriate mold steel material, and cut the mold steel material into the required blank size;

[0031] Step 2: Perform preliminary forging on the mold blank, use a milling machine to perform rough processing on the mold blank, then heat treat the mold blank, and then use a CNC machine tool to perform fine processing on the mold;

[0032] Step 3: Carry out surface treatment on the processed mold, assemble the various parts of the mold, and conduct a comprehensive quality inspection on the mold before putting it into production;

[0033] Step 4: placing the aluminum alloy blank heated to a certain temperature in the extrusion barrel of the extruder, preheating the mold, applying pressure through the extrusion rod to make the aluminum alloy blank pass through the mold cavity, putting lubricant between the aluminum alloy blank and the mold during extrusion, and extruding a profile of a desired shape;

[0034] Step 5: heat-treat the extruded profile, and then cool, straighten, cut and surface treat it;

[0035] Step 6: Conduct quality inspection on the finished profiles, including size inspection, surface quality inspection and mechanical property inspection. After passing the inspection, the aluminum alloy profiles are packaged.

[0036] In one embodiment of the present invention: in step one, the mold steel material is cut into the required blank size, the material of the mold is selected from tungsten-molybdenum alloy, the mold consists of a mold base, a mold core, a diverter hole, a welding chamber, a working belt, a feed port, a cooling system and an exhaust groove, the extrusion ratio of the mold is set to 5-20, the dimensional tolerance of the mold is less than ±0.05mm, the number of diverter holes is set to 6-10, and they are symmetrically distributed, the size of the diverter holes is selected from 5mm-20mm, the angle of the diverter holes is set to 30°-60°, the length of the working belt is set to 4mm-8mm, and the working belt is designed with transition fillets at different cross-sectional changes. The radius of the transition fillets is set to 0.5mm-2mm, the depth of the exhaust groove is set to 0.05mm-0.2mm, and the width is set to 3mm-8mm.

[0037] In one embodiment of the present invention: in step 2, the tungsten-molybdenum alloy is heated to 1400°C-1600°C by induction heating for 30min-60min, and the heated tungsten-molybdenum alloy is forged by a friction press, the forging speed is set to 10mm / s-30mm / s, the forging pressure is set to 150MPa-300MPa, the forging ratio is 3-8, and after forging, the tungsten-molybdenum alloy is placed in a heating furnace and slowly cooled with the furnace, and the cooled tungsten-molybdenum alloy is placed in a milling machine for rough machining, the tool uses a cemented carbide tool coated with a titanium nitride layer, the cutting speed is set to 30m / min-60m / min, the feed rate is set to 0.1mm / r-0.3mm / r, and the cutting depth is set The cutting fluid is 1mm-5mm, and cutting fluid is used for cooling and lubrication during cutting. The cutting fluid is emulsion, and the flow rate of the emulsion is set to 10L / min-20L / min. The tungsten-molybdenum alloy after rough machining is put into the heating furnace again for annealing. The annealing temperature is set to 1000℃-1400℃, and the insulation is 1h-3h. After annealing, furnace cooling is adopted, and the cooling rate is set to 10℃ / h-20℃ / h. After cooling, the tungsten-molybdenum alloy is placed in a CNC machine tool for fine machining. The tool material is polycrystalline cubic boron nitride, the cutting speed is set to 80m / min-120m / min, the feed rate is set to 0.05mm / r-0.15mm / r, and the cutting depth is set to 0.1mm-0.5mm.

[0038] In one embodiment of the present invention: in step three, a cleaning agent is used to clean the oil stains on the surface of each part of the processed tungsten-molybdenum alloy mold, and acetone is selected as the cleaning agent. After cleaning, the tungsten-molybdenum alloy mold is placed in a polishing machine for polishing. During rough polishing, a polishing paste with a particle size between 80-120 meshes is selected, and the abrasive of the polishing paste is selected from silicon carbide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 1200r / min-1500r / min. During fine polishing, a polishing paste with a particle size between 320-600 meshes is selected, and the abrasive of the polishing paste is selected from cerium oxide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 800r / min-1000r / min. Before assembly, a micrometer is used to measure the size of the mold, and the appearance of the mold parts is detected for bumps and scratches. After assembly, a trial mold is performed to observe the appearance quality of the trial mold product, including flash, material shortage and shrinkage defects, and the dimensional accuracy of the trial mold product is measured and compared with the design product size.

[0039] In one embodiment of the present invention: in step 4, the model of the aluminum alloy billet is 6063 aluminum alloy, and the aluminum alloy billet is heated by an induction heating furnace to 520°C-580°C. The mold is preheated by an external heating device before extrusion, and the preheating temperature is set to 400°C-500°C. During extrusion, the extrusion force of the extrusion rod is set to 100MPa-500MPa, and the extrusion speed is controlled to 5mm / s-20mm / s. During extrusion, a lubricant is used to act between the aluminum alloy and the mold, and the lubricant is glass powder. The amount of glass powder is 1%-3% of the weight of the aluminum alloy billet. The lubricating channel around the die hole of the mold injects the lubricant into the space between the aluminum alloy and the mold during the extrusion process, and the aluminum alloy billet passes through the mold cavity to extrude a profile of a required shape.

[0040] In one embodiment of the present invention: in step five, the extruded aluminum alloy profile enters an air circulation heating furnace for insulation treatment, the temperature of the air circulation heating furnace is set to 520℃-580℃, and the insulation is 30min-60min. The aluminum alloy profile after insulation is cooled in a mist cooling device, the diameter of the water mist particles is 10um-50um, the water mist temperature is set to 10℃-30℃, the mist cooling flow rate is set to 5L / min-20L / min, the pressure is set to 0.2MPa-0.5MPa, the movement speed of the profile is set to 0.1m / s-0.3m / s, and the mist cooling time is 30s-120s. The cooled aluminum alloy profile then enters a straightening device for straightening treatment.

[0041] In one embodiment of the present invention: In step 5, the aluminum alloy profile is straightened using a hydraulic press, and the section modulus of the aluminum alloy profile is first calculated using the formula:

[0042]

[0043] Among them, W represents the section modulus of the aluminum alloy profile, b represents the width of the aluminum alloy profile, h represents the height of the aluminum alloy profile, and 6 represents the mathematical coefficient determined by the geometric characteristics of the rectangular cross section and the definition of the section modulus. The straightening pressure is calculated based on the section modulus of the aluminum alloy profile. The calculation formula is:

[0044] P=σW

[0045] Among them, P represents the straightening pressure, σ represents the allowable bending stress, and the allowable bending stress is 50MPa-100MPa. The hydraulic press can straighten the aluminum alloy profile according to the calculated straightening pressure.

[0046] In one embodiment of the present invention: in step 5, a fully automatic saw is used to cut the straightened aluminum alloy profile, a bevel saw blade is selected, the number of teeth is selected to be 120-180 teeth, the diameter is 250mm-400mm, the sawing speed is set to 30000mm / min-60000mm / min, and the feed rate is set to 0.05-0.15mm / tooth. The aluminum alloy profile can be cut into a required length, and an alkaline solution is used to clean the surface of the cut aluminum alloy profile. The alkaline cleaning agent uses a sodium hydroxide solution with a mass fraction of 3%-5%, and the aluminum profile is immersed in it for 10min-15min, the temperature is maintained at 50℃-60℃, and then rinsed with clean water, and the aluminum alloy profile is placed in an electrolyte, and a DC power supply is connected. Under the action of the electric field, aluminum atoms lose electrons on the anode surface to form Al 3+ , Al 3+ Reacts with anions in the electrolyte to form an oxide film on the surface of the aluminum profile. The electrolyte is 15%-20% sulfuric acid by mass, and the current density is set to 1A / dm 2 -2A / dm 2 , the voltage is set to 12V-20V, and an oxide film is generated on the surface of the aluminum alloy profile, and the thickness of the oxide film is between 5um-20um.

[0047] In one embodiment of the present invention: in step six, a three-coordinate measuring instrument is used to measure the size of the produced aluminum alloy profile, and the dimensional tolerance is set between ±0.3mm. The surface of the aluminum alloy profile is directly observed by naked eyes to check whether there are obvious defects, including scratches, abrasions, pits, bubbles and cracks. The roughness of the profile surface is measured using a roughness meter, and the arithmetic mean roughness of the profile surface is 0.2um-0.8um. ​​The thickness of the oxide film on the surface of the profile is measured using a film thickness meter, and the thickness of the anodized film is between 5um-20um. A universal testing machine is used to perform a tensile test on the profile, and a hardness tester is used to measure the hardness of the profile. After passing the inspection, a suitable packaging material is selected according to the size, shape and transportation requirements of the profile. The packaging material uses a wooden packaging box, and the box is filled with foam plastic. The name, specification, quantity, production date and manufacturer's information of the profile must be indicated on the package.

[0048] Embodiment 1: For a hollow rectangular profile with an outer dimension of 50mm×30mm and a hollow part dimension of 30mm×10mm, four diversion holes are used, which are symmetrically distributed at the four corners of the mold, which can guide the billet to be evenly diverted, so that the flow of the billet in the mold is more stable and uniform. Good diversion can make the shape of the profile more accurate and the dimensional accuracy higher, reduce the stress concentration inside the profile, and improve its mechanical properties. The total area accounts for 35% of the cross-sectional area of ​​the billet. During extrusion, the aluminum alloy can be guided to flow evenly to the four sides of the rectangle and flow around the hollow part. The welding chamber is rectangular, 60mm long, 40mm wide, and 10mm high. Appropriate guide grooves are set in the welding chamber to guide the aluminum alloy to flow to the working belt. The length of the working belt is 6mm. The aluminum alloy billet Heated to 520℃, the mold was preheated to 430℃, and the extrusion speed was 5mm / s. A faster extrusion speed can reduce the unevenness of metal flow, thereby reducing the strain energy in the surrounding area and reducing the formation of coarse-grained rings. At the same time, glass powder was used as a lubricant during the extrusion process. At high temperature, the glass powder was converted from a solid state to a flowing state, forming a continuous, dense, and ductile compressive film layer on the contact surface between the blank and the mold. This film can effectively reduce the friction between the blank and the mold, making the aluminum alloy flow more easily during the extrusion process, helping to fill the mold cavity, improve the molding quality of the extruded product, reduce mold wear, and increase the service life of the mold. The wall thickness of the extruded hollow rectangular profile is uniform, the shape of the hollow part is regular, and the wall thickness tolerance is set within ±0.15mm.

[0049] Embodiment 2: In order to accurately control the temperature, it is necessary to install thermocouples on the heating device and the mold. The thermocouples can measure the temperature in real time and feed back the signal to the temperature control system. The temperature control system maintains the set temperature by adjusting the power of the heating device according to the feedback signal. For example, when the temperature is higher than the set value, the system will reduce the heating power; when the temperature is lower than the set value, the system will increase the heating power. This closed-loop control method can ensure that the aluminum alloy billet is always within the appropriate temperature range during the extrusion process; preheating the mold can reduce the temperature difference between the billet and the mold, avoid a sharp drop in the temperature of the billet when it contacts the mold, and thus improve the flow properties of the metal.

[0050] Example 3: For a rectangular aluminum alloy profile with a width of b = 30 mm and a height of h = 40 mm, the cross-sectional modulus of the alloy profile can be calculated to be 8000 mm 3, the allowable bending stress is 80MPa, then the required straightening pressure P=80×8000=640kN. When setting the pressure on the press, the accuracy of the press and the actual operating conditions must be considered. The accuracy of the press is ±3%. In order to achieve the calculated pressure of 640kN, the actual set pressure can be adjusted between 620-660kN, and the pressure setting is further optimized according to the actual response of the profile during the straightening process. Therefore, when setting the pressure, the set value should be appropriately adjusted according to the accuracy of the press. When the pressure begins to act on the profile, observe the deformation of the profile around the straightening point. If the profile begins to gradually straighten under the action of pressure, it means that the pressure direction is correct and the pressure size is appropriate. At this time, pay attention to whether there is new bending or deformation in other parts of the profile, because when straightening a bent part, it may cause stress changes in adjacent parts and produce new deformations.

[0051] Example 4: Using 16% sulfuric acid and a current density of 1.2 A / dm 2 , the voltage is set to 15V as the electrolyte, the growth rate of the oxide film in the electrolyte is relatively stable, the generated oxide film layer structure is relatively dense, the produced film layer porosity is moderate, the electrolyte temperature is set to 20℃, the conductivity and chemical reaction activity of the sulfuric acid electrolyte are in a relatively ideal state, the generated oxide film is uniform, and the oxidation is carried out for 60 minutes under the set parameters. The thickness of the oxide film that can be generated is 20um, which can effectively isolate the aluminum alloy profile from oxygen, moisture and corrosive media in the external environment. The anodized film itself has high hardness and wear resistance, which can enable the aluminum alloy profile to better withstand the friction and collision of objects.

[0052] As attached Figure 1 As shown, using tungsten-molybdenum alloy with high melting point, high hardness, high strength and good toughness as the material of the mold can withstand high temperature and high pressure during extrusion production. Preheating the mold during extrusion can reduce the temperature difference between the billet and the mold, reduce thermal stress, and improve the fluidity of the aluminum alloy. Injecting lubricant between the mold and the billet during extrusion can effectively reduce the friction between the mold and the billet, reduce the pressure required during processing, and extend the service life of the mold.

[0053] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

[0054] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0055] The above contents are merely examples and explanations of the present invention. Various modifications or additions to the specific embodiments described or replacements in similar ways by technicians in the technical field shall fall within the protection scope of the present invention as long as they do not deviate from the invention or exceed the scope defined by the claims.

[0056] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An aluminum alloy extrusion molding production process, including designing an extrusion die, performing surface heat treatment on the extrusion die, selecting an aluminum alloy material for heating and extrusion, performing surface treatment processing on the aluminum alloy profile after production, and packaging the aluminum alloy profile after passing the inspection, characterized in that: The specific steps of the aluminum alloy extrusion molding production process are as follows: Step 1: Design and material selection: design a suitable mold according to product requirements, select the appropriate mold steel material, and cut the mold steel material into the required blank size; Step 2: Perform preliminary forging on the mold blank, use a milling machine to perform rough processing on the mold blank, then heat treat the mold blank, and then use a CNC machine tool to perform fine processing on the mold; Step 3: Carry out surface treatment on the processed mold, assemble the various parts of the mold, and conduct a comprehensive quality inspection on the mold before putting it into production; Step 4: placing the aluminum alloy blank heated to a certain temperature in the extrusion barrel of the extruder, preheating the mold, applying pressure through the extrusion rod to make the aluminum alloy blank pass through the mold cavity, putting lubricant between the aluminum alloy blank and the mold during extrusion, and extruding a profile of a desired shape; Step 5: heat-treat the extruded profile, and then cool, straighten, cut and surface treat it; Step 6: Conduct quality inspection on the finished profiles, including size inspection, surface quality inspection and mechanical property inspection. After passing the inspection, the aluminum alloy profiles are packaged.

2. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step 1, the mold steel material is cut into the required blank size, the material of the mold is selected from tungsten-molybdenum alloy, the mold composition structure includes a mold base, a mold core, a diverter hole, a welding chamber, a working belt, a feed port, a cooling system and an exhaust groove, the extrusion ratio of the mold is set to 5-20, the dimensional tolerance of the mold is less than ±0.05mm, the number of diverter holes is set to 6-10, and they are symmetrically distributed, the size of the diverter holes is selected to be 5mm-20mm, the angle of the diverter holes is set to 30°-60°, the length of the working belt is set to 4mm-8mm, and the working belt is designed with transition fillets at different cross-section changes. The radius of the transition fillet is set to 0.5mm-2mm, the depth of the exhaust groove is set to 0.05mm-0.2mm, and the width is set to 3mm-8mm.

3. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step 2, the tungsten-molybdenum alloy is heated to 1400°C-1600°C by induction heating for 30min-60min, and the heated tungsten-molybdenum alloy is forged by a friction press, the forging speed is set to 10mm / s-30mm / s, the forging pressure is set to 150MPa-300MPa, the forging ratio is 3-8, and the tungsten-molybdenum alloy is placed in a heating furnace after forging, and slowly cooled with the furnace, and the cooled tungsten-molybdenum alloy is placed in a milling machine for rough machining, and a cemented carbide tool coated with a titanium nitride layer is used as the tool, the cutting speed is set to 30m / min-60m / min, the feed rate is set to 0.1mm / r-0.3mm / r, and the cutting depth is set to 1mm-5 mm, cutting fluid is used for cooling and lubrication during cutting, and the cutting fluid is emulsion, and the flow rate of the emulsion is set to 10L / min-20L / min. The tungsten-molybdenum alloy after rough machining is put into the heating furnace again for annealing, and the annealing temperature is set to 1000℃-1400℃, and the insulation is 1h-3h. After annealing, furnace cooling is adopted, and the cooling rate is set to 10℃ / h-20℃ / h. After cooling, the tungsten-molybdenum alloy is placed in the CNC machine tool for fine machining, and the tool material is polycrystalline cubic boron nitride. The cutting speed is set to 80m / min-120m / min, the feed rate is set to 0.05mm / r-0.15mm / r, and the cutting depth is set to 0.1mm-0.5mm.

4. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step three, a cleaning agent is used to clean the oil stains on the surfaces of various parts of the processed tungsten-molybdenum alloy mold, and acetone is selected as the cleaning agent. After cleaning, the tungsten-molybdenum alloy mold is placed in a polishing machine for polishing. During rough polishing, a polishing paste with a particle size between 80 and 120 meshes is selected, and the abrasive of the polishing paste is selected from silicon carbide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 1200r / min-1500r / min. During fine polishing, a polishing paste with a particle size between 320 and 600 meshes is selected, and the abrasive of the polishing paste is selected from cerium oxide particles, and the grease is selected from vaseline. The speed of the polishing machine is set to 800r / min-1000r / min. Before assembly, a micrometer is used to measure the size of the mold, and the appearance of the mold parts is detected for bumps and scratches. After assembly, a trial mold is performed to observe the appearance quality of the trial mold product, including flash, material shortage and shrinkage defects, and the dimensional accuracy of the trial mold product is measured and compared with the design product size.

5. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step 4, the model of the aluminum alloy blank is 6063 aluminum alloy, and the aluminum alloy blank is heated by an induction heating furnace to 520°C-580°C. The mold is preheated by an external heating device before extrusion, and the preheating temperature is set to 400°C-500°C. During extrusion, the extrusion force of the extrusion rod is set to 100MPa-500MPa, and the extrusion speed is controlled to 5mm / s-20mm / s. During extrusion, a lubricant is used to act between the aluminum alloy and the mold, and the lubricant is glass powder. The amount of glass powder is 1%-3% of the weight of the aluminum alloy blank. The lubricating channel around the mold hole of the mold injects the lubricant between the aluminum alloy and the mold during the extrusion process, and the aluminum alloy blank passes through the mold cavity of the mold to extrude a profile of a required shape.

6. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step five, the extruded aluminum alloy profile enters an air circulation heating furnace for insulation treatment, the temperature of the air circulation heating furnace is set to 520°C-580°C, and the insulation is 30min-60min. The aluminum alloy profile after insulation is cooled in a mist cooling device, the diameter of the water mist particles is 10um-50um, the water mist temperature is set to 10°C-30°C, the mist cooling flow rate is set to 5L / min-20L / min, the pressure is set to 0.2MPa-0.5MPa, the movement speed of the profile is set to 0.1m / s-0.3m / s, and the mist cooling time is 30s-120s. The cooled aluminum alloy profile then enters a straightening device for straightening treatment.

7. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step 5, the aluminum alloy profile is straightened using a hydraulic press. The section modulus of the aluminum alloy profile is first calculated using the formula: Among them, W represents the section modulus of the aluminum alloy profile, b represents the width of the aluminum alloy profile, h represents the height of the aluminum alloy profile, and 6 represents the mathematical coefficient determined by the geometric characteristics of the rectangular cross section and the definition of the section modulus. The straightening pressure is calculated based on the section modulus of the aluminum alloy profile. The calculation formula is: P=σW Among them, P represents the straightening pressure, σ represents the allowable bending stress, and the allowable bending stress is 50MPa-100MPa. The hydraulic press can straighten the aluminum alloy profile according to the calculated straightening pressure.

8. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step 5, a fully automatic saw is used to cut the straightened aluminum alloy profile, a bevel saw blade is selected, the number of teeth is selected to be 120-180 teeth, the diameter is 250mm-400mm, the sawing speed is set to 30000mm / min-60000mm / min, and the feed rate is set to 0.05-0.15mm / tooth, so that the aluminum alloy profile can be cut into a required length, and an alkaline solution is used to clean the surface of the cut aluminum alloy profile. The alkaline cleaning agent uses a sodium hydroxide solution with a mass fraction of 3%-5%, and the aluminum profile is immersed in it for 10min-15min, and the temperature is maintained at 50℃-60℃, and then rinsed with clean water, and the aluminum alloy profile is placed in an electrolyte, and a DC power supply is connected. Under the action of the electric field, aluminum atoms lose electrons on the anode surface to form Al 3+ , Al 3+ Reacts with anions in the electrolyte to form an oxide film on the surface of the aluminum profile. The electrolyte is 15%-20% sulfuric acid by mass, and the current density is set to 1A / dm 2 -2A / dm 2 , the voltage is set to 12V-20V, and an oxide film is generated on the surface of the aluminum alloy profile, and the thickness of the oxide film is between 5um-20um.

9. The aluminum alloy extrusion molding production process according to claim 1, characterized in that: In the step six, a three-coordinate measuring instrument is used to measure the size of the produced aluminum alloy profile, and the size tolerance is set between ±0.3mm. The surface of the aluminum alloy profile is directly observed by naked eyes to check whether there are obvious defects, including scratches, abrasions, pits, bubbles and cracks. The roughness of the profile surface is measured using a roughness meter, and the arithmetic mean roughness of the profile surface is 0.2um-0.8um. ​​The thickness of the oxide film on the surface of the profile is measured using a film thickness meter, and the thickness of the anodized film is between 5um-20um. A universal testing machine is used to perform a tensile test on the profile, and a hardness tester is used to measure the hardness of the profile. After passing the inspection, a suitable packaging material is selected according to the size, shape and transportation requirements of the profile. The packaging material uses a wooden packaging box, and the box is filled with foam plastic. The name, specification, quantity, production date and manufacturer information of the profile must be indicated on the package.

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