Magnesium alloy hot forging process

Abstract

The invention discloses a magnesium alloy hot forging process which comprises the following steps: step 1, material preparation: selecting proper magnesium alloy plates and profiles; step 2, heating treatment: carrying out cold forging and hot forging treatment on a magnesium alloy material; 3, forging and pressing forming is conducted, specifically, the heated magnesium alloy material is forged and pressed through a high-precision mold; 4, magnetic grinding is conducted, specifically, oxide skin and burrs on the surface of the disc brake piece are removed through a magnetic grinding technology; 5, smoothing treatment is conducted, specifically, the disc brake piece subjected to magnetic grinding is subjected to smoothing treatment; 6, high-end passivation is conducted, specifically, passivation treatment is conducted, and a layer of compact passivation film is formed on the surface of the disc brake piece; 7, acrylic acid electrophoretic paint coating is conducted, specifically, acrylic acid electrophoretic paint coating is conducted after passivating treatment; and 8, oil sealing treatment is conducted, specifically, oil sealing treatment is conducted finally, a layer of protective film is formed on the surface of the electrophoretic paint, the abrasion resistance and corrosion resistance of the disc brake piece are further improved, a proper oil sealing material is selected, and the oil sealing thickness and the drying time are controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of parts, and more particularly to a magnesium alloy hot forging process. Background Art

[0002] The disc brake system of bicycles (including electric bicycles) is crucial to riding safety. Disc brake parts need to have high strength, good wear resistance and corrosion resistance to cope with complex usage environments. Magnesium alloys have become potential high-quality materials for disc brake parts due to their low density, high specific strength and other characteristics. However, magnesium alloys have poor plasticity at room temperature, and traditional processing technology makes it difficult for them to meet the comprehensive mechanical properties and surface quality requirements required for disc brake parts. Hot forging technology can effectively improve the organizational structure of magnesium alloys and enhance their mechanical properties, providing possibilities for the application of magnesium alloys in the manufacture of disc brake parts. Summary of the invention

[0003] In view of this, the present invention provides a magnesium alloy hot forging process.

[0004] To achieve the above object, the present invention provides the following technical solution, comprising the following steps:

[0005] Step 1: Material preparation: Select suitable magnesium alloy sheets and profiles

[0006] Step 2: heating treatment, cold forging and hot forging the magnesium alloy material;

[0007] Step 3. Forging: Use a high-precision die to forge the heated magnesium alloy material, and accurately control the forging pressure, speed, stroke and other parameters according to the design requirements of the disc brake parts;

[0008] Step 4: Magnetic grinding: Use magnetic grinding process to remove the oxide scale and burrs on the surface of the disc brake parts;

[0009] Step 5: Polishing: Polish the disc brake parts after magnetic grinding;

[0010] Step 6: High-end passivation: Perform passivation treatment to form a dense passivation film on the surface of the disc brake;

[0011] Step 7: Acrylic electrophoretic paint: Apply acrylic electrophoretic paint after passivation treatment;

[0012] Step 8: Oil sealing treatment: Finally, oil sealing treatment is carried out to form a protective film on the surface of the electrophoretic paint to further improve the wear resistance and corrosion resistance of the disc brake parts. Select appropriate oil sealing materials and control the oil sealing thickness and drying time.

[0013] Preferably, in the above-mentioned magnesium alloy hot forging process, the hot forging is to place the magnesium alloy material in an oven and heat it to 320° C. and keep the temperature constant for ten minutes so that the material is evenly heated and fully softened to facilitate subsequent forging and forming.

[0014] Preferably, in the above-mentioned magnesium alloy hot forging process, the cold forging is a partial process or pre-processing and can be heated in a 180-degree oven to improve the material processing performance and refine the grains.

[0015] It can be known from the above technical scheme that compared with the prior art, the present invention discloses a magnesium alloy hot forging process, which selects magnesium alloy sheets / profiles of specific specifications and compositions, and after passing the inspection, puts them into an oven set at 320 degrees, keeps the constant temperature for ten minutes, and then quickly transfers them to the forging die for hot forging operation. After the formed disc brake parts are cooled to an appropriate temperature, they are magnetically ground and polished in turn, and then high-end passivation treatment is carried out under specific process conditions. After passivation is completed, acrylic electrophoretic paint is applied, and finally oil sealing treatment is carried out to obtain the final magnesium alloy hot forged bicycle (including electric bicycle) disc brake parts product. Throughout the process, the process parameters of each step are strictly monitored and recorded to ensure the stability and consistency of product quality. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] Embodiment 1

[0018] (I) Hot forging process of magnesium alloy

[0019] 1. Material preparation: Select suitable magnesium alloy sheets and profiles, and inspect the raw materials to ensure that their quality meets the requirements and there are no obvious defects.

[0020] 2. Heat treatment

[0021] Hot forging: Place the magnesium alloy material in an oven and heat it to 320 degrees, keeping the temperature constant for ten minutes to allow the material to be evenly heated and fully softened for subsequent forging and forming.

[0022] Cold forging (optional auxiliary process): Some processes or pre-processing can be heated in a 180-degree oven to improve material processing properties and refine grains.

[0023] 3. Forging: Use high-precision molds to forge the heated magnesium alloy material. According to the design requirements of the disc brake parts, accurately control the forging pressure, speed, stroke and other parameters to ensure the forming accuracy and quality.

[0024] (II) Post-processing process

[0025] 1. Magnetic grinding: The magnetic grinding process is used to remove defects such as oxide scale and burrs on the surface of the disc brake parts to improve the surface finish. The grinding effect is optimized by adjusting parameters such as magnetic field strength and grinding time during the grinding process.

[0026] 2. Polishing treatment: Polish the disc brake parts after magnetic grinding to further improve the surface quality, make the surface smoother and flatter, and reduce the surface roughness.

[0027] 3. High-end passivation: Passivation treatment is carried out to form a dense passivation film on the surface of the disc brake parts to enhance its corrosion resistance. Environmentally friendly passivating agents are used and process parameters such as passivation time, temperature and concentration are strictly controlled.

[0028] 4. Acrylic electrophoretic paint: Acrylic electrophoretic paint is applied after passivation treatment to improve the decorativeness and weather resistance of disc brake parts. During the electrophoretic painting process, parameters such as voltage, current and electrophoretic time are controlled to ensure uniform paint film thickness and strong adhesion.

[0029] 5. Oil sealing treatment: Finally, oil sealing treatment is carried out to form a protective film on the surface of the electrophoretic paint to further improve the wear resistance and corrosion resistance of the disc brake parts. Select appropriate oil sealing materials and control the oil sealing thickness and drying time.

[0030] The process of the present invention is described in detail below with reference to specific examples:

[0031] First, select magnesium alloy sheets / profiles of specific specifications and compositions. After passing the inspection, put them into an oven set at 320 degrees, keep the constant temperature for ten minutes, and then quickly transfer them to the forging die for hot forging. After the formed disc brake parts are cooled to the appropriate temperature, they are magnetically ground and polished in turn, and then high-end passivation treatment is carried out under specific process conditions. After passivation, acrylic electrophoretic paint is applied, and finally oil sealing treatment is carried out to obtain the final magnesium alloy hot forged bicycle (including electric bicycle) disc brake parts. Throughout the process, the process parameters of each step are strictly monitored and recorded to ensure the stability and consistency of product quality.

[0032] Embodiment 2

[0033] (I) Hot forging process of magnesium alloy

[0034] 1. Material selection and pretreatment: Select magnesium alloy plates and profiles of appropriate grades and specifications, and conduct strict appearance inspection and composition testing to ensure that the material quality is stable and free of internal defects such as pores and inclusions.

[0035] 2. Hot forging heating: Place the magnesium alloy material in a professional industrial oven, heat it to 320°C, and keep it at a constant temperature for ten minutes to ensure that the internal structure of the material is evenly heated and reaches the best hot forging plastic state. This temperature setting is based on a large number of experiments and theoretical analysis of the thermal deformation characteristics of magnesium alloys and the forming requirements of disc brake parts. It can effectively refine the grains and improve the fluidity of the material, which is conducive to subsequent forging and forming.

[0036] 3. Forging: Use high-precision, high-strength dies to forge the heated magnesium alloy. According to the precise design drawings of the disc brake parts, the computer numerical control system accurately controls the key parameters of forging pressure, speed, holding time, etc., so as to ensure the dimensional accuracy of the disc brake parts, and the shape and position tolerances meet the relevant high-precision standards, while making the internal structure of the material denser and significantly improving the mechanical properties.

[0037] (II) Post-processing process

[0038] 1. Magnetic grinding: Special magnetic grinding equipment is used to finely grind the surface of the hot-forged disc brake parts using magnetic abrasives under the action of the magnetic field. By adjusting the magnetic field strength, abrasive particle size, grinding time and other parameters, the oxide layer, tiny burrs, forging lines and other defects on the surface of the disc brake parts can be effectively removed, and the surface roughness can be reduced to the preset value.

[0039] 2. Polishing treatment: The disc brake parts after magnetic grinding are placed in a polishing machine. Through the mutual friction with a specific polishing medium (such as a mixture of fine ceramic particles and polishing liquid), the surface finish is further improved, making the surface present a mirror effect. The surface roughness can be stabilized below the preset value, greatly improving the appearance quality and anti-friction performance of the disc brake parts.

[0040] 3. High-end passivation: Use environmentally friendly and efficient passivators to passivate the disc brake parts. Under strictly controlled temperature, time and passivator concentration conditions, a uniform, dense and self-repairing passivation film is formed on the surface of the disc brake parts. The thickness of the passivation film can reach 10-30μm, which significantly enhances the corrosion resistance of the disc brake parts. After the neutral salt spray test, there is no obvious rust for more than 5 hours.

[0041] 4. Acrylic electrophoretic paint: Put the passivated disc brake parts into the electrophoretic paint tank for acrylic electrophoretic coating. Accurately control the electrophoretic voltage, current and electrophoretic time to form a layer of acrylic electrophoretic paint film with strong adhesion and uniform thickness (about 10-30μm) on the surface of the disc brake parts. This paint film has good decorative, weather resistance and water resistance, effectively protecting the disc brake parts substrate and improving its appearance quality.

[0042] 5. Oil sealing treatment: Finally, special high-quality oil sealing materials are used to seal the disc brake parts after electrophoretic painting. Under strict control of the thickness of the oil seal and the drying conditions, a transparent, smooth and wear-resistant oil sealing layer is formed, which further improves the wear resistance, corrosion resistance and anti-fingerprint pollution ability of the disc brake parts, ensuring the surface quality and performance stability of the disc brake parts during long-term use.

[0043] First, magnesium alloy raw materials, such as AZ91D magnesium alloy sheets, are selected according to the design requirements. A comprehensive quality inspection is carried out on it, including ultrasonic flaw detection for internal defects and spectral analysis of chemical composition. After passing the inspection, the sheet is cut into suitable billet sizes and placed in an oven preheated to 320°C, and kept at a constant temperature for ten minutes. Subsequently, the billet is quickly transferred to the mold of the forging equipment, and forged according to the set forging parameters to obtain the preliminary shape of the disc brake parts. After the formed disc brake parts are cooled to room temperature, they are magnetically ground in the magnetic grinding equipment in turn, then polished in the polishing machine, then passivated in the passivation tank, and then coated with acrylic electrophoretic paint in the electrophoretic paint tank, and finally sealed in the oil sealing equipment, thereby obtaining the final high-quality magnesium alloy hot-forged bicycle (including electric bicycle) disc brake parts. During the entire production process, an automated monitoring system is used to monitor and record each process parameter in real time to ensure the traceability and stability of product quality. Each batch of products is sampled and tested. The testing items include mechanical properties testing (tensile strength, yield strength, hardness, etc.), surface quality testing (roughness measurement, paint film adhesion testing, passivation film thickness testing, etc.) and corrosion resistance testing (neutral salt spray test). Only products whose testing indicators meet the relevant standards can enter the market for sales and application.

[0044] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0045] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A magnesium alloy hot forging process, characterized in that: The following steps are involved: Step 1: Material preparation: Select suitable magnesium alloy sheets and profiles Step 2: heating treatment, cold forging and hot forging the magnesium alloy material; Step 3. Forging: Use a high-precision die to forge the heated magnesium alloy material, and accurately control the forging pressure, speed, stroke and other parameters according to the design requirements of the disc brake parts; Step 4: Magnetic grinding: Use magnetic grinding process to remove the oxide scale and burrs on the surface of the disc brake parts; Step 5: Polishing: Polish the disc brake parts after magnetic grinding; Step 6: High-end passivation: Perform passivation treatment to form a dense passivation film on the surface of the disc brake; Step 7: Acrylic electrophoretic paint: Apply acrylic electrophoretic paint after passivation treatment; Step 8: Oil sealing treatment: Finally, oil sealing treatment is carried out to form a protective film on the surface of the electrophoretic paint to further improve the wear resistance and corrosion resistance of the disc brake parts. Select appropriate oil sealing materials and control the oil sealing thickness and drying time.

2. A magnesium alloy hot forging process according to claim 1, characterized in that: The hot forging in step 2 is to place the magnesium alloy material in an oven and heat it to 320° C. and keep the temperature constant for ten minutes so that the material is evenly heated and fully softened to facilitate subsequent forging and forming.

3. A magnesium alloy hot forging process according to claim 1, characterized in that: In step 2, cold forging is a partial process or pre-processing, and a 180-degree oven heating treatment can be used to improve the material processing performance and refine the grains.