A semi-solid forming process for smart glasses magnesium-aluminum alloy components

Abstract

The application discloses a semi-solid forming process of a magnesium-aluminum alloy component of intelligent glasses, and the process comprises the following steps: preparing a Mg-Al magnesium-aluminum alloy melt with specific components; preparing a semi-solid slurry with a solid phase rate of 30-50% at 610-630 DEG C through composite electromagnetic stirring of a rotating magnetic field and a traveling wave magnetic field; preheating a mold and spraying a nano-alumina-based lubricant; adopting a stepped pressurization injection process for thixotropic forming; and finally, performing integrated heat treatment of solid solution, deep cooling and aging on the formed piece. Through systematic cooperation of material component optimization, slurry homogenization preparation, precision forming and strengthening heat treatment, the application effectively solves technical problems such as insufficient filling, coarse structure and uneven performance of traditional processes in manufacturing ultra-thin-wall and complex-structure intelligent glasses components, realizes high-precision, high-performance and high-consistency manufacturing of the products, and is particularly suitable for batch production of components such as frames and legs.

Description

Technical Field

[0001] This invention relates to the field of precision metal forming technology, and in particular to a semi-solid forming process for magnesium-aluminum alloy components for smart glasses. Background Technology

[0002] With the rapid development of wearable smart devices, smart glasses, as an important branch, have placed extremely stringent requirements on the performance of key structural components (such as frames, temples, and nose pads). These requirements are mainly reflected in: extreme lightweighting to improve wearing comfort, excellent specific strength to protect internal precision electronic components, good molding precision and surface quality to meet aesthetic and assembly needs, and excellent heat dissipation to ensure stable device operation.

[0003] Magnesium-aluminum alloys (Mg-Al alloys) are ideal materials for manufacturing lightweight structural components for smart glasses due to their low density, high specific strength, excellent electromagnetic shielding, and heat dissipation. However, current traditional magnesium alloy forming technologies, such as die casting or conventional thixoforming, have revealed many insurmountable technical bottlenecks when applied to ultra-thin-walled, structurally complex, and dimensionally precise components like smart glasses.

[0004] 1. Molding Defects: In traditional die casting processes, high-speed, high-pressure filling easily generates turbulence, leading to severe defects such as air entrapment, shrinkage cavities, and flow marks inside the molded parts. For smart glasses components with wall thicknesses often below 1 mm, these defects significantly reduce their mechanical properties (especially fatigue strength) and surface quality, resulting in low yield.

[0005] 2. Insufficient material properties: Magnesium alloys obtained by conventional casting have coarse grains and uneven microstructure, which directly results in the strength and toughness (elongation) of the components failing to meet the requirements of long-term, dynamic wear of smart glasses. Although this can be improved through subsequent heat treatment, the inherent defects of traditional forming processes often become the "ceiling" for performance improvement.

[0006] 3. Challenges in Mold Filling and Lifespan: The components of smart glasses have intricate and complex structures. In traditional liquid molding, although the molten metal has good fluidity, it also exhibits significant solidification shrinkage, resulting in incomplete filling of thin-walled areas and a tendency for "under-casting." Simultaneously, the high-temperature magnesium alloy melt causes severe erosion and thermal fatigue to the mold, reducing mold lifespan and increasing production costs.

[0007] 4. Limitations of Traditional Semi-Solid Processes: While semi-solid molding technology can reduce turbulence and shrinkage, conventional processes (such as mechanical stirring to prepare slurries) suffer from inaccurate control of the slurry solids ratio and non-uniform spherical grain size. When applied to ultra-precision components, this leads to inconsistent microstructures, resulting in dimensional fluctuations and performance dispersion, making it difficult to meet the stability requirements of mass production. Furthermore, existing processes lack comprehensive optimization across the entire process, from slurry preparation and mold interaction to post-processing, specifically for magnesium-aluminum alloys used in the unique structure of smart glasses.

[0008] Therefore, the industry urgently needs to develop a targeted, high-precision magnesium-aluminum alloy forming process that can stably and efficiently produce ultra-thin-walled components for smart glasses with uniform and dense structure, excellent mechanical properties, precise dimensions, and smooth surfaces, in order to break through the limitations of existing technologies and promote the lightweight and high-performance development of smart glasses products. Summary of the Invention

[0009] The main objective of this invention is to provide a semi-solid forming process for magnesium-aluminum alloy components of smart glasses, in order to overcome the shortcomings of the prior art.

[0010] This invention provides a semi-solid forming process for magnesium-aluminum alloy components of smart glasses, comprising the following steps: S1, Raw material preparation: Selecting a Mg-Al magnesium-aluminum alloy, wherein the Al content is 3-9wt%, the Zn content is 0.5-1.5wt%, the Mn content is 0.2-0.6wt%, and the balance is Mg; S2, Melting treatment: Melting the magnesium-aluminum alloy raw material under a protective atmosphere at a melting temperature of 680-720℃ for 20-40 minutes to obtain an alloy melt; S3, Semi-solid slurry preparation: Transferring the alloy melt into an electromagnetic stirring device and performing electromagnetic stirring at a temperature of 610-630℃, a stirring frequency of 10-30Hz, and a stirring time of [missing information]. S4. Mold pretreatment: Preheat the mold for the smart glasses component to 250-350℃ and spray nano-alumina-based lubricant on the cavity surface; S5. Thixochemical molding: Transfer the semi-solid slurry to the injection chamber and inject it into the mold cavity under a pressure of 80-150MPa and an injection speed of 0.2-0.8m / s, with a holding time of 10-30 seconds; S6. Solution treatment: Solution treat the molded part at 410-430℃ for 4-8 hours, followed by water quenching; S7. Aging treatment: Aging treatment at 175-195℃ for 12-24 hours to obtain the magnesium-aluminum alloy component for the smart glasses.

[0011] Preferably, in step S3, the electromagnetic stirring device adopts a combined stirring method of rotating magnetic field and traveling magnetic field, wherein the frequency of rotating magnetic field is 15-25Hz and the frequency of traveling magnetic field is 5-15Hz.

[0012] Preferably, the composition of the nano-alumina-based lubricant in step S4 is as follows: 20-40 wt% nano-alumina particles with a particle size of 50-100 nm; 10-20 wt% silicate binder; and the balance being a water-based carrier; the coating thickness of the lubricant is 10-30 μm.

[0013] Preferably, the injection process in step S5 adopts stepped pressurization control, including: in the first stage, filling the cavity to 70-80% at a low speed of 0.1-0.3m / s, and in the second stage, filling the remaining cavity at a high speed of 0.5-0.8m / s.

[0014] Preferably, step S6, after solution treatment, further includes a cryogenic treatment step: placing the quenched molded part in a cryogenic environment of -80 to -120°C for 1-3 hours.

[0015] Preferably, the protective atmosphere in step S2 is a mixture of CO2 and SF6 with a volume ratio of 99:1 and a gas flow rate of 5-15 L / min.

[0016] Preferably, the smart glasses component is a frame, temple, or nose pad component, and the minimum wall thickness of the component after molding is 0.6-1.2mm.

[0017] Preferably, the solid fraction of the semi-solid slurry in step S3 is controlled by real-time ultrasonic monitoring. When the solid fraction is detected to reach the set range, stirring is stopped immediately and the slurry is transferred.

[0018] Compared with existing technologies, the semi-solid forming process for magnesium-aluminum alloy components of smart glasses of this invention achieves high-precision and high-integrity forming of ultra-thin-walled complex structures by precisely designing the composition of magnesium-aluminum alloy and innovatively using composite electromagnetic stirring to prepare semi-solid slurry. Combined with stepped pressure injection and mold surface pretreatment technology, this process achieves component minimum wall thickness of 0.6-1.2 mm without undercast defects. After integrated heat treatment of solution, cryogenics, and aging, the component obtains a uniform and fine microstructure with an average grain size controlled at 20-50 micrometers. It exhibits excellent comprehensive mechanical properties, with a tensile strength of 280-350 MPa and an elongation of 8-15%, fully meeting the dual requirements of lightweight and structural reliability for smart wearable devices. Simultaneously, this process significantly reduces thermal shock to the mold and extends its service life through optimized semi-solid forming temperature and the application of a special lubricant. The entire production process has clear parameters and strong controllability, making it particularly suitable for large-scale mass production, providing an efficient and reliable solution for the manufacturing of precision lightweight structural components such as smart glasses. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 A semi-solid forming process flow diagram of a magnesium-aluminum alloy component for smart glasses provided in an embodiment of the present invention.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1 A semi-solid forming process for magnesium-aluminum alloy components of smart glasses includes the following steps:

[0024] S1. Raw material preparation

[0025] This step uses a Mg-Al magnesium-aluminum alloy with a specific composition range, specifically:

[0026] The Al content is controlled between 3-9 wt%. The main role of aluminum is to improve the strength and corrosion resistance of the alloy. When the Al content is below 3%, the alloy strength is insufficient; when it is above 9%, the brittle β-Mg phase is present. 17 Al 12 Too much will reduce toughness.

[0027] The Zn content is 0.5-1.5wt%. The addition of zinc can produce a solid solution strengthening effect, and at the same time form a strengthening phase with aluminum, thereby improving the strength and hardness of the alloy.

[0028] The Mn content is 0.2-0.6wt%. The main role of manganese is to form Al-Mn compounds, refine the grains, and improve the corrosion resistance of the alloy.

[0029] The balance is Mg and unavoidable impurities, and the total amount of impurities should be controlled below 0.3%.

[0030] S2, Smelting Processing

[0031] The smelting process is carried out under a protective atmosphere to prevent oxidation and combustion of the magnesium alloy. The preferred protective atmosphere is a mixture of CO2 and SF6, with SF6 content approximately 1%. The smelting temperature is controlled between 680-720℃ and held for 20-40 minutes to ensure complete homogenization of the alloy composition. Too low a temperature will result in incomplete melting, while too high a temperature will cause significant evaporation and oxidation of magnesium.

[0032] S3, Semi-solid slurry preparation

[0033] The molten alloy is transferred to an electromagnetic stirring device and stirred within a temperature range of 610-630℃. This temperature falls within the liquid-solid two-phase region of the alloy. The Lorentz force generated by electromagnetic stirring shears and breaks up the growing dendrites, forming spherical or near-spherical primary solid particles. The stirring frequency is 10-30Hz, and the time is 3-8 minutes, ultimately yielding a semi-solid slurry with a solid content of 30-50%. If the solid content is too low, the slurry is close to a liquid state, losing the advantages of semi-solid molding; if it is too high, the slurry viscosity is too high, making molding difficult.

[0034] S4. Mold Pretreatment

[0035] The mold for molding smart glasses components is preheated to 250-350℃. The purpose of preheating is twofold: first, to reduce the temperature gradient during the filling of the semi-solid slurry and prevent premature solidification; and second, to reduce thermal stress on the mold. Then, a nano-alumina-based lubricant is sprayed onto the cavity surface to form an isolation film, facilitating demolding and protecting the mold.

[0036] S5, thixotropic deformation

[0037] The semi-solid slurry is rapidly transferred to the injection chamber and injected into the mold cavity at a pressure of 80-150 MPa and a speed of 0.2-0.8 m / s. Under pressure, the semi-solid slurry exhibits pseudoplastic fluid characteristics; the shear-thinning effect reduces its viscosity and enhances its flowability during filling, which is beneficial for filling thin-walled complex structures. Holding pressure for 10-30 seconds ensures shrinkage compensation and reduces shrinkage cavities.

[0038] S6, Solution treatment and aging treatment

[0039] Solution treatment: Hold at 410-430℃ for 4-8 hours to allow the strengthening phase in the alloy to fully dissolve into the magnesium matrix, forming a supersaturated solid solution, and then fix this state by water quenching.

[0040] Aging treatment: Hold at 175-195℃ for 12-24 hours to allow the supersaturated solid solution to precipitate fine, dispersed strengthening phases, resulting in a significant aging strengthening effect.

[0041] Furthermore, in step S3, the electromagnetic stirring device employs a combined stirring method of rotating magnetic field and traveling wave magnetic field:

[0042] Rotating magnetic field: Generated by multiphase coils arranged along the circumference, the direction of the magnetic field rotates with time, and the frequency is controlled between 15-25Hz. The rotating magnetic field induces eddy currents in the melt, generating a circumferential electromagnetic force that drives the melt to rotate as a whole, which is beneficial for the macroscopic uniform mixing of the melt.

[0043] Traveling wave magnetic field: generated by coils arranged in a straight line, the magnetic field propagates along the axis, and the frequency is controlled between 5-15Hz. The traveling wave magnetic field generates an axial electromagnetic thrust, which drives the melt to flow in a specific direction, forming a strong shear flow.

[0044] Composite effect: The superposition of two magnetic fields creates a complex three-dimensional flow field, exerting multi-directional, high-frequency shearing action on the solidifying dendrites, resulting in more thorough dendrite breakage and more rounded, uniformly sized primary solid particles. This composite stirring method is more effective than single stirring modes in eliminating the inhomogeneity of the temperature and composition fields, producing a more stable semi-solid slurry. During stirring, the temperature must be precisely controlled within a narrow range of 610-630℃.

[0045] Semi-solid slurries were prepared using a single rotating magnetic field (25Hz), a single traveling wave magnetic field (10Hz), and the composite magnetic field of this invention (20Hz rotating + 8Hz traveling wave). Statistical analysis was performed on the primary solid particles in the slurries, and the results are shown in Table 1 below.

[0046] Table 1 - Influence of different stirring methods on the characteristics of primary phase particles in semi-solid slurry preparation

[0047]

[0048] The formula for calculating sphericity is (4π × area) / perimeter. 2 The closer the value is to 1, the more spherical the particles. From the above analysis, it can be seen that the particles obtained by composite stirring have the best sphericity (closest to 1), the most concentrated size distribution (smallest standard deviation), and the most stable solid fraction control. This is because the three-dimensional shear flow field generated by the composite magnetic field is more uniform, avoiding particle elongation or agglomeration caused by shearing in one direction.

[0049] Furthermore, in step S4, the composition and spraying requirements of the nano-alumina-based lubricant used in the mold pretreatment are as follows:

[0050] Nano-alumina particles (20-40wt%): Particle size is strictly controlled within 50-100nm. Nanoparticles have high hardness, high melting point and high chemical stability. Under high pressure and high temperature, they can form a strong isolation and friction-reducing layer on the mold surface, effectively preventing direct contact and welding between magnesium alloy and mold steel.

[0051] Silicate binder (10-20wt%): such as water glass, its function is to firmly bond nano-alumina particles to the mold surface and form a dense silicate ceramic film at high temperature, thereby enhancing the adhesion and durability of the coating.

[0052] The remaining amount is a water-based carrier: convenient for spraying, and environmentally friendly and pollution-free.

[0053] Using specialized spraying equipment, the prepared lubricant is evenly sprayed onto the preheated mold cavity surface, controlling the spray thickness to be 10-30μm. A coating that is too thin will provide insufficient protection, while a coating that is too thick will affect the dimensional accuracy and surface finish of the components. After spraying, the lubricant can be dried and cured at the mold's preheating temperature.

[0054] Mold life comparison experiment:

[0055] Under the same process conditions, 10,000 magnesium-aluminum alloy parts were continuously produced using both traditional graphite-based lubricants and the nano-alumina-based lubricant of this invention. The mold wear depth, demolding force, and surface defect rate of the parts were then tested. The results are shown in Table 2 below.

[0056] Table 2 - Effects of different types of lubricants on mold performance and component surface quality

[0057]

[0058] Mechanism analysis: Nano-alumina particles (hardness approximately 9 Mohs) form a physical barrier at high temperatures. Electron microscopy analysis shows that after using the lubricant of this invention, the protective film formed on the mold surface is continuous and dense, with a thickness of approximately 15 μm; while the film formed by traditional lubricants is uneven, with local cracks, causing the mold to directly contact the magnesium alloy and resulting in welding wear.

[0059] Furthermore, the injection process in step S5 employs stepped pressurization control, including:

[0060] The first stage (low-speed filling): The slurry is smoothly injected into the cavity at a low speed (0.1-0.3 m / s) until it fills 70-80% of the total cavity volume. The main purpose of this stage is to ensure that the slurry flows smoothly in a laminar flow, avoiding turbulence and thus effectively preventing gas entrapment and oxide inclusions, ensuring the internal quality of the molded part. It is particularly suitable for filling the main runner, cross runner, and initial thin-walled areas.

[0061] The second stage (high-speed filling): As the slurry tip approaches the end of the cavity, the injection speed is rapidly increased to 0.5-0.8 m / s to quickly fill the remaining 20-30% of the cavity, and high pressure is applied at the endpoint for holding. This ensures that the slurry temperature decreases, viscosity increases, and fluidity deteriorates towards the end of the filling process, allowing the high-speed filling to quickly fill the entire cavity before the slurry completely solidifies, especially in difficult-to-fill areas such as the furthest points and ribs, preventing underfill defects. Simultaneously, the impact at the high-speed end also facilitates pressure transmission and enhances the feeding effect.

[0062] Internal quality comparative analysis:

[0063] Industrial CT (industrial computed tomography) was used to scan magnesium-aluminum alloy parts formed by three different injection molding methods. The internal porosity and pore size were statistically analyzed, and the pore distribution characteristics were observed. The results are shown in Table 3 below.

[0064] Table 3 - Comparison of internal pore characteristics of parts formed by different injection molding methods

[0065]

[0066] The results in the table above show that: constant low-speed filling results in insufficient filling pressure at the end, leading to inadequate packing; constant high-speed filling generates significant turbulent gas entrainment. The solution of this invention reduces gas entrainment through stable low-speed filling and ensures complete filling and packing through high-speed end filling, resulting in optimal internal quality.

[0067] Furthermore, after the solution treatment in step S6, a cryogenic treatment step is also included: the quenched molded part is quickly transferred to a cryogenic device (such as a liquid nitrogen cryogenic chamber) and kept in a low temperature environment of -80℃ to -120℃ for 1-3 hours, and then taken out and allowed to recover to room temperature in the air.

[0068] Although magnesium alloys lack austenite, cryogenic treatment minimizes point defects such as vacancies in the magnesium matrix, resulting in a more regular lattice arrangement. The enormous thermal stress generated by cryogenic treatment induces a large number of uniformly distributed microdislocations within the material. These dislocations can serve as preferential nucleation sites for strengthening phases (such as the β' phase) during subsequent aging treatment, thereby promoting the precipitation of finer and more dispersed strengthening phases and significantly improving the material's strength and toughness. The uniform cryogenic process also helps to partially release the internal stress generated by quenching, improving dimensional stability. Experiments have shown that cryogenically treated magnesium alloy components exhibit significantly improved strength, hardness, and wear resistance, along with reduced anisotropy.

[0069] For samples from the same batch after solution treatment, the following methods were applied: a) direct aging; b) aging after cryogenic treatment (-100℃ / 2h). The mechanical properties are compared in Table 4 below.

[0070] Table 4 - Effects of cryogenic treatment on the mechanical properties of components

[0071]

[0072] Transmission electron microscopy (TEM) revealed that the β' strengthening phase precipitated in the cryogenically treated sample was smaller in size (average diameter of about 15 nm, compared to about 25 nm in the non-cryogenically treated sample), and its distribution density was increased by about 40%. The micro-stress field generated by cryogenic treatment provided more nucleation sites, which is the fundamental reason for the performance improvement.

[0073] Furthermore, during the smelting process in step S2, a protective atmosphere with a specific composition is employed. The protective atmosphere is a mixture of CO2 and SF6 in a volume ratio of 99:1. CO2 is the primary gas and has a low cost; SF6 is a highly efficient flame retardant, and a content of 1% is sufficient to form a dense protective film of MgF2 on the melt surface, effectively preventing the oxidation and combustion of magnesium. The gas flow rate is controlled at 5-15 L / min to maintain positive pressure in the furnace and prevent air backflow. Too low a flow rate results in insufficient protection, while too high a flow rate leads to waste and may disturb the melt surface.

[0074] In this embodiment, the smart glasses components are frames, temples, or nose pads. These components share common characteristics: complex structures (often including slots, hinges, wiring channels, etc.), extremely thin walls (minimum wall thickness requirement of 0.6-1.2mm), and high requirements for dimensional accuracy and surface quality. Traditional die-casting processes struggle to meet these requirements, while the semi-solid process of this invention, with its excellent slurry flowability (shear thinning) and low solidification shrinkage, can perfectly replicate the intricate structure of the mold, achieving high-integrity molding of such ultra-thin-walled complex parts. The molded components require little or no machining for assembly, resulting in high production efficiency and material utilization.

[0075] Furthermore, in the semi-solid slurry preparation process of step S3, a real-time ultrasonic monitoring system is introduced to perform closed-loop control of the slurry's solid fraction. An ultrasonic probe is installed on the side wall of the electromagnetic stirring tank, with the probe pointing towards the core area of ​​the slurry. Ultrasonic waves have different propagation speeds and attenuation coefficients in solid and liquid media. By measuring the sound velocity and attenuation signal of the ultrasonic waves after passing through the slurry in real time, a correlation model between the ultrasonic waves and the slurry's solid fraction can be established. A target solid fraction range is set (e.g., 40% ± 5%). When the ultrasonic monitoring system determines that the current slurry's solid fraction has reached the lower limit of the set range, the system issues a command to immediately stop the electromagnetic stirring and trigger the slurry transfer mechanism to quickly transfer the qualified semi-solid slurry to the injection chamber.

[0076] This method changes the traditional experience-based (fixed time / temperature) control approach, enabling online, real-time, and precise control of key slurry quality indicators. It ensures the consistency of slurry state between different batches, fundamentally guaranteeing the stability of the final product performance, and is key to achieving intelligent and high-quality production.

[0077] 1. To comprehensively evaluate the technical effects of the present invention, a systematic comparative test experiment was conducted on the components manufactured using the technical solutions of the embodiments of the present invention, the traditional liquid die casting process, and the conventional semi-solid molding process, focusing on their comprehensive performance in terms of molding quality, mechanical properties, microstructure characteristics, and process stability.

[0078] The present invention group adopts the technical solutions of the above embodiments of the present invention.

[0079] Comparison Group 1: Traditional Liquid Die Casting Process

[0080] Comparison Group 2: Conventional semi-solid molding (single stirring, no ultrasonic monitoring, no cryogenic treatment)

[0081] 1.1 The magnesium-aluminum alloy frame components for smart glasses were manufactured using the process of this invention, the traditional liquid die casting process (Comparative Group 1), and the conventional semi-solid molding process (Comparative Group 2). Ten production batches were selected for each group, with 100 magnesium-aluminum alloy frame components produced per batch. All molded parts underwent appearance defect screening (e.g., undercasting, cracks, surface flow marks, etc.), and the percentage of qualified parts was calculated as the molding pass rate. Industrial CT scanning technology was used to comprehensively inspect the 0.6mm thin-walled area, assessing the filling integrity and calculating the percentage of fully filled parts. According to the sampling standard GB / T2828.1-2012, test samples were selected, and 30 key dimensional inspection points were chosen. Each batch of components was measured individually using a high-precision dimensional measuring instrument, and the dimensional accuracy CPK was calculated to characterize dimensional accuracy stability. CPK ≥ 1.33 was considered to meet precision manufacturing requirements, and CPK ≥ 1.67 was considered a high-precision level. The results are shown in Table 5 below:

[0082] Table 5 - Comparison of Molding Quality

[0083]

[0084] 1.2 Ten samples were randomly selected from the components manufactured by the three groups (Group 1, Comparative Group 2) respectively, and tensile specimens (dumbbell shape, gauge length diameter 5 mm, length 25 mm) were prepared according to the standard. Tensile tests were conducted using an electronic universal testing machine according to GB / T228.1-2021 "Metallic Materials - Tensile Testing - Part 1: Tests at Room Temperature". Tension was applied at a loading rate of 2 mm / min. The yield point load, maximum load, and gauge length change after fracture were recorded. The yield strength, tensile strength, elongation, and their corresponding average values ​​were calculated. Ten evenly distributed measuring points were selected on the component surface, and the microhardness (HV) was measured using a Vickers hardness tester with a loading force of 100 g and a holding time of 15 s. The average value of the 10 measuring points was taken as the final hardness value. All tests were conducted at room temperature (25℃). The results are shown in Table 6 below:

[0085] Table 6 - Comparison of Mechanical Properties

[0086]

[0087] 1.3. Core area samples were cut from the components formed by the processes of the three groups: the present invention group, Comparative Group 1, and Comparative Group 2. After grinding, polishing, and etching (using 4% nitric acid alcohol solution), metallographic samples were prepared. The microstructure morphology was observed using a scanning electron microscope (SEM), and the average grain size was calculated. Specifically, the intercept method was used; five different fields of view were selected in the SEM metallographic image, and the intercept length of the grains in each field of view was measured. The average value was calculated as the average grain size.

[0088] The quantitative analysis function of industrial CT scans the number and volume of pores within the sample, calculates the percentage of the total pore volume to the total sample volume, and takes the average of three measurements to quantitatively analyze the internal porosity.

[0089] The size and distribution of the reinforcing phase were analyzed using transmission electron microscopy (TEM). Ten typical reinforcing phase particles were selected from the TEM images, their diameters were measured, and the average size was calculated (control group 1 was not detected because it did not undergo optimized heat treatment and therefore had no obvious reinforcing phase). The results are shown in Table 7 below:

[0090] Table 7 - Comparison of Organizational Characteristics

[0091]

[0092] 1.4 Ten batches of magnesium-aluminum alloy frame components for smart glasses, each consisting of 100 pieces, were selected from three batches of components continuously formed using the process of this invention, the traditional liquid die casting process (Comparative Group 1), and the conventional semi-solid molding process (Comparative Group 2). The tensile strength data for each batch was recorded, and the ratio of the standard deviation to the average tensile strength of the ten batches was calculated. A smaller ratio indicates less fluctuation and better process stability, thus characterizing the strength fluctuation between batches.

[0093] Continuously monitor the wear of the mold during use. Use a high-precision surface roughness tester and profilometer to periodically detect the wear depth of the mold cavity. When the wear depth reaches 0.1mm, stop counting and count the cumulative number of produced parts to characterize the mold life.

[0094] The controllability and stability of the process were evaluated by considering two aspects: the fluctuation in component strength between batches and the mold life. The results are shown in Table 8 below:

[0095] Table 8 - Comparison of Process Stability

[0096]

[0097] 2. Magnesium-aluminum alloy frame components prepared by the process of this invention and traditional stainless steel frame components were selected as test samples, with 30 pieces selected from each group. Specific tests were conducted on five core application indicators: single-piece weight, heat dissipation performance, fatigue life, first-pass yield, and corrosion resistance.

[0098] Single piece weight: Using an electronic balance with an accuracy of 0.01g, each of the 30 parts in each group was weighed individually, and the average value was taken as the final single piece weight data.

[0099] Heat dissipation performance: The two sets of components were assembled into complete smart glasses. In a constant temperature environment of 25℃ and good ventilation, the smart glasses were simulated to work continuously at rated power for 2 hours under normal working load (fixed heat generation power of internal electronic components). The stable working temperature of the center point of the frame surface was measured using an infrared thermometer.

[0100] Fatigue life: The two sets of components are assembled into complete smart glasses. A special reciprocating opening and closing fatigue testing machine is used to conduct reciprocating opening and closing tests on the key stress parts of the frame (i.e., the hinge parts) at the opening and closing angle (0-120°) and frequency (10 times / minute) of the smart glasses during daily wear, until the components break or cannot open and close normally, and the cumulative number of opening and closing times is recorded.

[0101] First-pass yield: In a standard production line assembly environment, professional assembly workers perform assembly operations on two sets of components according to the conventional production assembly process, and the percentage of components that can be successfully assembled without secondary adjustments is counted.

[0102] Corrosion resistance: In accordance with GB / T10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", the corrosion was accelerated by salt spray environment. The two sets of components were placed in a 5% NaCl salt spray test chamber, the temperature was maintained at 35℃, and continuous spray test was conducted. The corrosion of the component surface was observed periodically, and the time of the first appearance of corrosion (pitting corrosion, rust, etc.) was recorded.

[0103] The results are shown in Table 9 below:

[0104] Table 9 - Application Performance Comparison

[0105]

[0106] 3. Economic Analysis

[0107] Using the process of this invention and the traditional die-casting process as research objects, the economic cost of producing 100,000 magnesium-aluminum alloy frame components of smart glasses of the same specifications was evaluated, and statistical analysis was conducted on four core economic indicators: material utilization rate, comprehensive cost per unit, mold maintenance cycle, and energy consumption index.

[0108] Material utilization rate: The total amount of raw materials (by weight) required to produce 100,000 parts is evaluated and calculated in relation to the total weight of the finished parts. Material utilization rate = (total weight of finished parts / total amount of raw materials) × 100%.

[0109] Unit comprehensive cost: The total cost of production is calculated, including raw material costs, energy consumption costs, mold depreciation costs, labor costs, maintenance costs, etc. Unit comprehensive cost = total production cost / total production volume (100,000 units). The cost of the process of this invention is used as the benchmark value to compare the cost difference with that of the traditional die casting process.

[0110] Mold maintenance cycle: The estimated cumulative number of production parts when the mold first shows wear that affects product quality (such as cavity size deviation exceeding the allowable range, surface roughness deterioration, etc.) during the two sets of production processes, i.e., the mold maintenance cycle.

[0111] Energy consumption indicators: The total electricity consumption and gas consumption during the production of 100,000 parts are estimated and calculated using the energy metering device of the production equipment. These are then converted into standard energy consumption. The energy consumption of the process of this invention is used as the benchmark value to compare the energy consumption of the traditional die casting process.

[0112] The results are shown in Table 10 below:

[0113] Table 10 - Economic Comparison

[0114]

[0115] The above experimental data fully demonstrates that this invention, through systematic process innovation and the organic integration of multiple technological features, has achieved comprehensive optimization of the manufacturing process of magnesium-aluminum alloy components for smart glasses. All performance indicators are significantly superior to traditional processes, particularly in thin-wall forming capability, mechanical property combination, production stability, and economy, fully meeting the stringent requirements of high-end smart wearable devices for lightweight, high-performance structural components.

[0116] In summary, the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content shall be considered equivalent embodiments of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A semi-solid forming process for magnesium-aluminum alloy components of smart glasses, characterized in that, Includes the following steps: S1. Raw material preparation: Select Mg-Al series magnesium-aluminum alloy, wherein the Al content is 3-9wt%, the Zn content is 0.5-1.5wt%, the Mn content is 0.2-0.6wt%, and the balance is Mg; S2. Melting treatment: Melt the magnesium-aluminum alloy raw material under a protective atmosphere at a melting temperature of 680-720℃ and hold for 20-40 minutes to obtain the alloy melt. S3. Semi-solid slurry preparation: The alloy melt is transferred into an electromagnetic stirring device and electromagnetically stirred at a temperature of 610-630℃, with a stirring frequency of 10-30Hz and a stirring time of 3-8 minutes to obtain a semi-solid slurry with a solid content of 30%-50%. S4. Mold pretreatment: Preheat the mold for forming smart glasses components to 250-350℃ and spray nano-alumina-based lubricant onto the cavity surface; S5, Thixoforming: The semi-solid slurry is transferred to the injection chamber and injected into the mold cavity under a pressure of 80-150MPa and an injection speed of 0.2-0.8m / s, with a holding time of 10-30 seconds; The injection process employs stepped pressurization control, including: the first stage filling the cavity to 70%-80% at a low speed of 0.1-0.3 m / s, and the second stage filling the remaining cavity at a high speed of 0.5-0.8 m / s. S6. Solution treatment: The molded part is solution treated at 410-430℃ for 4-8 hours, followed by water quenching; after solution treatment, a cryogenic treatment step is also included: the quenched molded part is placed in a cryogenic environment of -80 to -120℃ for 1-3 hours. S7. Aging treatment: Aging treatment at 175-195℃ for 12-24 hours to obtain magnesium-aluminum alloy parts for smart glasses, and the minimum wall thickness of the formed parts is 0.6-1.2mm.

2. The semi-solid forming process for a magnesium-aluminum alloy component of smart glasses as described in claim 1, characterized in that, In step S3, the electromagnetic stirring device adopts a combined stirring method of rotating magnetic field and traveling magnetic field, wherein the frequency of rotating magnetic field is 15-25Hz and the frequency of traveling magnetic field is 5-15Hz.

3. The semi-solid forming process for a magnesium-aluminum alloy component of smart glasses as described in claim 1, characterized in that, The composition of the nano-alumina-based lubricant in step S4 is as follows: 20wt%-40wt% nano-alumina particles with a particle size of 50-100nm; 10wt%-20wt% silicate binder; the balance being a water-based carrier; and the coating thickness of the lubricant is 10-30μm.

4. The semi-solid forming process for a magnesium-aluminum alloy component of smart glasses as described in claim 1, characterized in that, The protective atmosphere in step S2 is a mixture of CO2 and SF6 with a volume ratio of 99:1 and a gas flow rate of 5-15 L / min.

5. The semi-solid forming process for a magnesium-aluminum alloy component of smart glasses as described in claim 1, characterized in that, The smart glasses components are frames, temples, or nose pads.

6. The semi-solid forming process for a magnesium-aluminum alloy component of smart glasses as described in claim 1, characterized in that, In step S3, the solid fraction of the semi-solid slurry is controlled by real-time ultrasonic monitoring. When the solid fraction is detected to reach the set range, stirring is stopped immediately and the slurry is transferred.

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