Aluminum material high-finish polishing process

Abstract

The present application relates to a kind of high finish polishing process of aluminum material, belong to bathroom product semi-finished aluminum part polishing technical field, by introducing constant temperature constraint and subarea correlation parameter in fine polishing stage, the thermal state of polishing contact area is directly controlled, on the one hand, the polishing agent is preheated and kept warm at 120 DEG C±2 DEG C, and continuously supplied to polishing wheel in fine polishing process, so that polishing contact area continuously obtains temperature stable lubrication or heat exchange medium, from source, weaken the random fluctuation of friction heat generation, on the other hand, the surface to be polished of complex aluminum part is divided into three zones according to geometric edge and surface transition degree, and the gradient relationship of linear velocity, contact pressure and polishing agent supply amount is configured respectively, so that the edge corner orifice area prone to stress concentration and instantaneous overheating is matched with higher supply amount at lower speed and lower pressure to obtain stronger lubrication and thermal stability, reduce the defects such as adhesion, drag mark, fogging and uneven gloss caused by local overheating, improve appearance consistency and reduce rework rate.

Description

Technical Field

[0001] This invention belongs to the field of polishing technology for semi-finished aluminum parts of bathroom products, specifically involving a high-gloss polishing process for aluminum materials. Background Technology

[0002] In the bathroom product sector, to obtain a high-gloss surface for aluminum profiles or aluminum alloy exterior parts, a combination of mechanical grinding and polishing is typically used to treat the surface of semi-finished aluminum parts. Existing processes generally include deburring and cleaning the aluminum parts, followed by coarse grinding, medium grinding, and fine grinding to gradually eliminate extrusion marks, tool marks, and grinding lines. Then, a polishing wheel and polishing compound are used for pre-polishing and fine polishing to achieve a high mirror reflection effect. After polishing, the parts are cleaned to remove polishing residue, and surface protection treatments such as anodizing, electrophoresis, or coating are applied according to product requirements.

[0003] However, semi-finished aluminum parts in the bathroom industry often have complex structures such as corners, openings, narrow edges, and curved transitions, and some are thin-walled or hollow profiles. During the contact process between the polishing wheel and the workpiece, large changes in contact area, localized load concentration, and unstable heat dissipation paths are likely to occur. As a result, the frictional heat generation in the polishing contact area exhibits localized and instantaneous characteristics. In the existing process, the polishing section often relies on fixed rhythms or operator experience to adjust pressure, speed, and wax or paste application. Cooling and heat dissipation methods are also often intermittent or crude, making it difficult to maintain a stable temperature in the polishing contact area. Once the local temperature is too high, it is easy to cause appearance defects such as adhesion, drag marks, fogging, uneven brightness, and magnification of minor scratches on the aluminum surface, thereby increasing the rework rate and reducing the consistency and yield of finished products. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a high-gloss polishing process for aluminum materials. This process solves the problems of unstable temperature in the polishing contact area, localized instantaneous overheating, or temperature drift in the high-gloss polishing stage of semi-finished aluminum materials in the bathroom industry. These issues lead to surface defects such as adhesion, drag marks, fogging, and uneven gloss, resulting in poor consistency, high rework rate, and reduced yield.

[0005] The objective of this invention can be achieved through the following technical solutions: A high-gloss polishing process for aluminum materials includes the following steps: S1: Pre-treatment, deburring and shaping of semi-finished aluminum materials, followed by degreasing, cleaning, rinsing and drying; S2: Rough grinding and leveling, using coarse-grained abrasive to rough grind the surface of the semi-finished aluminum material to be polished, in order to remove extrusion marks, tool marks, dents and obvious scratches; S3: Medium grinding and finishing, using medium-sized abrasive to perform medium grinding on the surface after coarse grinding, in order to eliminate coarse grinding marks and obtain a uniform substrate; S4: Fine grinding refinement, using fine-grained abrasive to fine grind the surface after intermediate grinding in order to further reduce surface roughness; S5: Constant Temperature Zoned Polishing. The polishing agent is preheated and maintained at 120℃±2℃. During the polishing process, the polishing agent is continuously supplied to the polishing surface of the polishing wheel, maintaining the working temperature of the polishing contact area between the polishing wheel and the semi-finished aluminum material at 120℃±2℃. Simultaneously, the surface to be polished is divided into a first polishing area, a second polishing area, and a third polishing area according to the geometric edges and the degree of curved surface transition. The first polishing area is for corners, openings, or small rounded corner transitions; the third polishing area is for large flat areas or large arcs; and the second polishing area is located within the first… Between the polishing area and the third polishing area; the first polishing area, the second polishing area and the third polishing area are finely polished in sequence, and the polishing linear speeds corresponding to the first polishing area, the second polishing area and the third polishing area are v1, v2 and v3 respectively, satisfying v1 < v2 < v3, the corresponding polishing contact pressures are p1, p2 and p3 respectively, satisfying p1 < p2 < p3, and the corresponding polishing agent supply amounts are q1, q2 and q3 respectively, satisfying q1 ≥ q2 ≥ q3, so that the working temperature of the polishing contact area of ​​each polishing area is maintained at 120℃ ± 2℃; S6: Post-cleaning and surface treatment: Cleaning and drying the semi-finished aluminum material after fine polishing, removing the polishing agent, and then performing subsequent surface protection treatment.

[0006] As a further embodiment of the present invention, in step S5, the first polishing area includes corners, the periphery of orifices, or narrow edges with a feature width W ≤ 10 mm on the surface to be polished with a radius of curvature R ≤ 3 mm; the third polishing area includes large arc portions or planar portions on the surface to be polished with a radius of curvature R ≥ 10 mm; the second polishing area is a transition portion with a radius of curvature satisfying 3 mm < R < 10 mm, or a strip-shaped transition area located between the first polishing area and the third polishing area.

[0007] As a further embodiment of the present invention, in step S5, the polishing linear velocity satisfies: v2 = (1.2~1.6)·v1, v3 = (1.2~1.6)·v2; the polishing contact pressure satisfies: p2 = (1.3~2.0)·p1, p3 = (1.3~2.0)·p2; and the polishing agent supply amount satisfies: q2 = (0.6~0.9)·q1, q3 = (0.6~0.9)·q2, so that the heat input of the three polishing zones is progressively matched with the lubrication and heat exchange conditions.

[0008] As a further aspect of the present invention, in step S5, when the first polishing area, the second polishing area, and the third polishing area are finely polished, the single polishing contact times are t1, t2, and t3, respectively, satisfying t1≥t2≥t3, and further satisfying the following relationship: (v1.p1.t1) / q1=(v2.p2.t2) / q2=(v3.p3.t3 / q3)q1.v1.p1.t1=q2.v2.p2.t2=q3.v3.p3.t3, so that the unit polishing intensity of different regions under constant temperature constraint is coordinated with the material supply lubrication, thereby suppressing local overheating and gloss differences.

[0009] As a further aspect of the present invention, in step S5, before fine polishing the first polishing area, the polishing wheel is idling and a polishing agent at a temperature of 120℃±2℃ is continuously supplied for 10s to 60s to form a continuous wetting layer on the polishing surface of the polishing wheel. Then, fine polishing is performed sequentially on the first polishing area, the second polishing area, and the third polishing area to reduce the temperature rise peak and drag marks caused by the fluctuation of the initial friction coefficient.

[0010] As a further embodiment of the present invention, in step S5, the polishing wheel is integrally provided with a first polishing belt, a second polishing belt and a third polishing belt along the axial direction, and the compressive hardness of the three belts satisfies the condition that the first polishing belt < the second polishing belt < the third polishing belt; in S5, the first polishing belt, the second polishing belt and the third polishing belt are used to perform fine polishing on the first polishing area, the second polishing area and the third polishing area respectively, so as to achieve zoned thermal-mechanical matching through the structural differences of the same polishing wheel.

[0011] As a further aspect of the present invention, in step S5, the first polishing area is polished using an intermittent contact polishing method, with each contact time being 0.3s to 1.5s and the detachment time being 0.2s to 1.0s, and the process is repeated cyclically. The second polishing area is polished using an intermittent contact polishing method, with each contact time being 0.5s to 2.0s and the detachment time being 0.1s to 0.5s. The third polishing area is polished using a continuous contact polishing method, so that the stress concentration area obtains a periodic heat dissipation window, further suppressing local temperature rise peaks.

[0012] As a further aspect of the present invention, in step S5, when the second polishing area is finely polished, the polishing trajectory forms a cross angle of 30° to 90° relative to the grinding pattern direction formed by the fine grinding in S4, and the polishing trajectory of the second polishing area overlaps with the first polishing area and the third polishing area by 5mm to 20mm respectively, so as to eliminate the gloss steps and hazy boundaries at the partition boundaries.

[0013] As a further embodiment of the present invention, in step S5, when switching from the first polishing area to the second polishing area, or from the second polishing area to the third polishing area, the polishing wheel is in contact with the dressing block for 1s to 10s while continuously supplying polishing agent to discharge the metal chips and polishing agent residue embedded in the polishing wheel, thereby stabilizing the surface condition of the polishing wheel and the level of frictional heat generation, and improving the consistency of constant temperature fine polishing.

[0014] As a further aspect of the present invention, after completing the fine polishing of the first polishing area, the second polishing area, and the third polishing area, a full-coverage finishing polishing step is added in step S5: the surface to be polished is fully covered and polished, the polishing linear speed during finishing polishing is v0 and satisfies v0≥v3, the polishing contact pressure is p0 and satisfies p0<p1, the polishing agent supply is q0 and satisfies q3≤q0≤q2, and the working temperature is maintained at 120℃±2℃ to further eliminate micro-haze and unify the mirror clarity and gloss consistency.

[0015] The beneficial effects of this invention are as follows: By introducing isothermal constraints and combining them with zone-related parameters in the polishing process, the thermal state of the polishing contact area is stabilized. On the one hand, the polishing agent is preheated and kept at 120℃±2℃ and continuously supplied to the polishing wheel, so that the polishing contact area obtains a lubricating or heat exchange medium with a stable temperature, thereby reducing the random fluctuations of frictional heat generation from the source. On the other hand, the surface to be polished is divided into three types of regions according to the degree of transition between geometric edges and curved surfaces: a first polishing region, a second polishing region, and a third polishing region. Gradients are set for the linear velocity v, contact pressure p, and polishing agent supply q for the three types of regions, and they are interconnected, with v1<v2<v3 and p1<p2. <p3, q1≥q2≥q3, so that the stress concentration area can obtain stronger lubrication and lower heat input, and the non-concentration area can obtain higher efficiency but still be constrained by constant temperature. In this way, the temperature of the polishing contact area in each region is suppressed within the target range, reducing adhesion, drag marks, haze and uneven gloss caused by local overheating, improving appearance consistency and yield. This solves the problem that in the high-gloss polishing stage of semi-finished aluminum materials in the bathroom industry, the polishing contact area temperature is difficult to stabilize, local instantaneous overheating or temperature drift occurs, which causes appearance defects such as adhesion, drag marks, haze and uneven gloss on the aluminum surface, resulting in poor consistency, high rework rate and low yield. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a flowchart of the high-gloss polishing process for aluminum materials according to the present invention. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0019] Please see Figure 1 As shown, this embodiment provides a high-gloss polishing process for aluminum materials, including the following steps: S1: Pre-treatment, deburring and shaping of semi-finished aluminum materials, followed by degreasing, cleaning, rinsing and drying; S2: Rough grinding and leveling. Coarse abrasive is used to rough grind the surface of the semi-finished aluminum material to be polished in order to remove extrusion marks, tool marks, dents and obvious scratches. S3: Medium grinding and finishing, using medium-sized abrasive to perform medium grinding on the surface after coarse grinding, in order to eliminate coarse grinding marks and obtain a uniform substrate; S4: Fine grinding refinement, using fine-grained abrasive to fine grind the surface after intermediate grinding in order to further reduce surface roughness; S5: Constant Temperature Zoned Polishing. The polishing compound is preheated and maintained at 120℃±2℃. During the polishing process, the polishing compound is continuously supplied to the polishing surface of the polishing wheel, maintaining the working temperature of the polishing contact area between the polishing wheel and the semi-finished aluminum material at 120℃±2℃. Simultaneously, the surface to be polished is divided into three polishing zones according to the geometric edges and the degree of curvature transition. The first polishing zone is for corners, openings, or small rounded corners; the third polishing zone is for large flat areas or large arcs; and the second polishing zone is located within the first polishing zone. Between the first polishing area and the third polishing area; the first polishing area, the second polishing area and the third polishing area are finely polished in sequence, and the polishing linear speeds corresponding to the first polishing area, the second polishing area and the third polishing area are v1, v2 and v3 respectively, satisfying v1 < v2 < v3, the corresponding polishing contact pressures are p1, p2 and p3 respectively, satisfying p1 < p2 < p3, and the corresponding polishing agent supply amounts are q1, q2 and q3 respectively, satisfying q1 ≥ q2 ≥ q3, so that the working temperature of the polishing contact area of ​​each polishing area is maintained at 120℃ ± 2℃; S6: Post-cleaning and surface treatment: Cleaning and drying the semi-finished aluminum material after fine polishing, removing the polishing agent, and then performing subsequent surface protection treatment.

[0020] In the high-gloss polishing stage of semi-finished aluminum materials in the bathroom industry, existing technologies often suffer from unstable temperatures in the polishing contact area, leading to localized instantaneous overheating or temperature drift. This results in surface defects such as adhesion, drag marks, fogging, and uneven gloss, causing poor consistency, high rework rates, and reduced yield. This application provides an embodiment that directly controls the thermal state of the polishing contact area by introducing constant temperature constraints and zone-related parameters during the fine polishing stage. On one hand, the polishing agent is preheated and maintained at 120℃±2℃ and continuously supplied to the polishing wheel during fine polishing, ensuring the polishing contact area receives a consistently stable lubricating / heat exchange medium, thus reducing random fluctuations in frictional heat generation from the source. On the other hand, complex... The surfaces of aluminum parts to be polished are divided into three polishing zones based on their geometric edges and the degree of curvature transition: a first polishing zone, a second polishing zone, and a third polishing zone. A gradient relationship is configured for the linear velocity, contact pressure, and polishing agent supply for each zone, with v1 < v2 < v3, p1 < p2 < p3, and q1 ≥ q2 ≥ q3. This allows areas prone to stress concentration and instantaneous overheating, such as corners and orifices, to achieve stronger lubrication and thermal stability at lower speeds and pressures combined with a higher supply. Meanwhile, larger areas remain under constant temperature constraints even with higher efficiency parameters. This keeps the temperature of the polishing contact areas within the target range, reducing defects such as adhesion, drag marks, haze, and uneven gloss caused by localized overheating, improving appearance consistency, and reducing rework rates.

[0021] It is important to note that the aforementioned combination of pretreatment—gradual grinding—temperature-controlled zoned fine polishing—post-cleaning—surface treatment is necessary because achieving a high gloss finish depends not only on the final fine polishing but also on the gradual elimination of extrusion marks, tool marks, and grinding marks in the preceding processes to build a uniform substrate. In the fine polishing stage, which is most prone to thermal instability due to its complex structure, temperature control is embedded within the process constraints. The polishing compound is supplied at a constant temperature and continuously, the contact area temperature is maintained at 120℃±2℃, and the speed, pressure, and polishing compound supply are configured in a gradient according to geometric sensitivity. This transforms the operation from experience-based wax application based on gloss and pressure control by feel to a reproducible parameter system. The direct benefits are: more controllable heat input during fine polishing, more stable lubrication, less risk of burns or drag marks on edges and openings, improved polishing efficiency over large areas, and more uniform overall gloss, thus significantly improving yield and batch consistency. It also provides a more stable high-gloss substrate for subsequent anodizing, electrophoresis, or coating surface protection treatments.

[0022] Even after dividing the first, second, and third polishing areas according to the geometric edges and the degree of surface transition, inconsistencies in zoning standards still arise in actual production. Different operators, different batches, or different product models may have different understandings of "corners, small rounded corners, transitions, and large arcs / flat surfaces," especially on narrow edges, the perimeter of openings, and local transition zones commonly found on bathroom aluminum parts. Without quantifiable criteria, stress concentration areas can easily be misjudged as large areas, leading to the application of higher speeds or pressures, resulting in localized instantaneous overheating, fogging, or scratches. Conversely, misjudging large areas as corner areas can cause decreased efficiency, insufficient brightness, and loss of cycle control. To address this issue, in one embodiment, in step S5, the first polishing area includes corners, the perimeter of openings, or narrow edges with a feature width W ≤ 10mm on the surface to be polished with a radius of curvature R ≤ 3mm; the third polishing area includes areas with a radius of curvature R ≥ 3mm on the surface to be polished. The first polishing area is a large arc or flat area with a radius of curvature of 10mm. The second polishing area is a transition area with a radius of curvature of 3mm < R < 10mm, or a strip-shaped transition area between the first and third polishing areas. By introducing a quantitative threshold for the radius of curvature R and the feature width W (e.g., R ≤ 3mm or W ≤ 10mm defines the first polishing area, R ≥ 10mm defines the third polishing area, and 3mm < R < 10mm is the second polishing area), empirical partitioning is transformed into geometric partitioning. The corners, orifices, and narrow edges most prone to thermal instability are accurately separated from the transition and large surfaces, so that the subsequent gradient settings of speed, pressure, and supply can be applied stably and repeatedly. The benefits are that the partitioning consistency is significantly improved, the process is easier to standardize, and training and tooling procedures are easier to implement. At the same time, it can reduce local burns, hazy boundaries, or gloss steps caused by partitioning errors, thereby further improving the mirror consistency of batch products.

[0023] Furthermore, although the above specifies that the parameters of the three types of regions should satisfy the directional relationship of "v1 < v2 < v3, p1 < p2 < p3, q1 ≥ q2 ≥ q3", in actual implementation, the problem of "unreasonable gradient magnitude" may still occur. If the increase of v and p is too small, the difference between the three regions is insufficient to offset the load concentration and heat dissipation difference caused by geometry, and the corner areas may still overheat due to the high local friction work density; if the increase is too large, it will cause a sharp increase in heat input or too fast polishing in the second and third regions, resulting in fogging, ghosting or brightness jumps. At the same time, if the decrease of q is not matched, it will also lead to insufficient lubrication. Therefore, it is necessary to give a more controllable proportional range on the basis of only the magnitude rule to avoid the arbitrariness of parameter selection. In this regard, in one embodiment, in step S5, the polishing linear velocity satisfies: v2 = (1.2 ~ 1.6) · v1, v3 = (1.2 ~ 1.6) · v2, and the polishing contact pressure satisfies: p2 = (1 The polishing agent supply satisfies: q2 = (0.6~0.9)·q1, q3 = (0.6~0.9)·q2, so that the heat input and lubrication and heat exchange conditions of the three polishing areas are progressively matched. Here, the parameter gradient of each area is constrained by multiple intervals. The design logic is to map the geometric differences of the area into a mild but sufficient process gradient. The speed and pressure are gradually increased to improve the polishing efficiency and mirror-forming ability of the transition area and the large area, while the polishing agent supply is gradually decreased to avoid splashing, wheel clogging or surface residue caused by excessive polishing agent in the large area. At the same time, the interval restriction prevents the lubrication from dropping suddenly. The advantage is that the process can be more easily calibrated quickly by scaling the whole based on v1, p1, q1 on different equipment and different product sizes, taking into account efficiency and thermal stability, reducing parameter adjustment time and reducing local overheating or uneven gloss caused by parameter span loss.

[0024] Furthermore, after establishing a gradient relationship between speed, pressure, and supply, a key variable remains: the polishing contact time. Polishing contact time disrupts temperature stability and gloss consistency. The corners and openings of bathroom aluminum components typically require more meticulous processing to eliminate minor scratches and edge haze. Operators often increase pauses or repeat contact, while larger areas tend to be processed quickly. If there is a lack of correlation between contact time and supply, speed, and pressure, even with reasonable settings for v, p, and q, excessive time and insufficient supply may lead to overheating of corners, or insufficient time may result in insufficient polishing of transition areas or boundaries, resulting in steps and haze. To avoid this problem, in one embodiment, during fine polishing of the first, second, and third polishing areas in step S5, the single polishing contact times are t1, t2, and t3, respectively, satisfying t1 ≥ t2 ≥ t3, and further satisfying the following relationship: (v1.p1.t1) / q1=(v2.p2.t2) / q2=(v3.p3.t3 / q3)q1.v1.p1.t1=q2.v2.p2.t2=q3.v3.p3.t3, so that the unit polishing intensity of different regions under isothermal constraints is coordinated with the material supply and lubrication, thereby suppressing local overheating and gloss differences. By limiting the single contact time of each region to satisfy t1≥t2≥t3, and further using the correlation between v·p·t and q to couple the heat input and lubrication supply of the three regions, in other words, this can be understood as... Matching the frictional work input and polishing agent supply in different areas ensures that the frictional work per unit supply in each area is at the same level. This is necessary to achieve the objective requirement of longer processing time for edges and corners without overheating, while reducing v and p and increasing q. The benefits are: firstly, the time gradient ensures that the first polishing area completes the mirror finish of details under safer thermal conditions; secondly, the equivalent thermal load matching reduces temperature drift caused by differences in dwell time between the three areas, thereby reducing the probability of scratches, haze, and brightness jumps, and improving the uniformity of the overall mirror finish clarity.

[0025] Furthermore, in actual operation, the polishing agent is required to be kept at a constant temperature of 120℃±2℃ and continuously supplied to maintain a stable contact area temperature. However, at the beginning of the actual fine polishing, the polishing surface of the polishing wheel is often not fully wetted, and the polishing agent has not yet formed a continuous film or a stable carrying state on the wheel surface. When the polishing wheel first contacts the workpiece, the coefficient of friction and heat generation will change abruptly. Especially when the first polishing area is treated, instantaneous scratches, fogging, or drag marks are more likely to occur, causing defects and affecting the consistency of subsequent processes. Therefore, it is necessary to solve the problem of unstable wheel surface state at the initial stage of fine polishing. In this regard, in one embodiment, in step S5, before fine polishing the first polishing area, the polishing wheel is idled and continuously supplied with polishing agent at a temperature of 120℃±2℃ for 10s to 60s, so that the polishing surface of the polishing wheel forms a continuous immersion. After applying a wetted layer, the polishing is then performed sequentially in the first, second, and third polishing zones to reduce temperature spikes and drag marks caused by fluctuations in the initial friction coefficient. Specifically, before entering the first polishing zone, a pre-wetting step is added where the polishing wheel idles and continuously supplies polishing compound at 120℃±2℃ for 10-60 seconds. The purpose of this design is to allow the polishing wheel surface to first form a continuous wetted layer and achieve a more stable friction and heat exchange state before contacting the workpiece. The advantage of this is that the fine polishing is under fully lubricated and temperature-controlled working conditions from the very first second, significantly reducing the risk of initial transient heat peaks and dry friction scratches, minimizing initial drag marks and haze, and making it easier for subsequent zone parameters to stabilize the contact area temperature within the target range, thereby improving the mirror finish consistency and repeatability of the entire product.

[0026] Although speed, pressure, and supply can regulate heat input and lubrication, the compressive hardness of the polishing wheel body also determines the contact area, pressure distribution, and local friction work density. If a harder polishing wheel is used in small rounded areas such as corners and orifices, the contact area is smaller and the stress is more concentrated, which can easily lead to local overheating and edge scratches. On the other hand, if a softer polishing wheel is used in large flat areas or large arcs, insufficient support may result in low mirror-forming efficiency and a wavy or uneven brightness. Therefore, relying solely on the v, p, and q gradients may not be able to simultaneously ensure the contact stability and efficiency of the three types of areas. In this regard, in one embodiment, in step S5, the polishing wheel is integrally provided with a first polishing belt, a second polishing belt, and a third polishing belt along the axial direction, and the compressive hardness of the three belts satisfies the condition that the first polishing belt < the second polishing belt < the third polishing belt. In S5, the first polishing belt, the second polishing belt, and the third polishing belt are respectively used to correspond to the first polishing area and the second polishing area. The first and third polishing zones are finely polished to achieve thermal-mechanical matching of the zones through the structural differences of the same polishing wheel. Specifically, the polishing wheel is integrally set with the first, second, and third polishing belts along the axial direction, and their compressive hardness is limited to the condition that the first polishing belt < the second polishing belt < the third polishing belt. They are used for the first, second, and third polishing zones respectively. Here, the wheel surface compliance gradient is used to match the geometric sensitivity gradient. The first polishing belt is softer to improve the adhesion, expand the effective contact area, and alleviate the load concentration at the corners and openings. The second polishing belt provides transition support to balance adhesion and efficiency. The third polishing belt is harder to ensure the forming efficiency and mirror clarity of large areas. This design can stabilize the contact state of each zone without significantly increasing the complexity of operation, reduce local burns, scratches, or insufficient brightness caused by hardness mismatch, and further improve the repeatability and cycle stability of constant temperature zone fine polishing.

[0027] Following the above embodiments, even with lower v1 and p1 and increased q1, heat accumulation may still occur in the corner orifice area due to poor heat dissipation, small heat capacity, and thin-walled structure. Especially during continuous contact polishing, frictional heat can accumulate in a short time, forming local temperature peaks. The second polishing area, as a transition zone, has geometry and heat dissipation conditions between the two. Using a completely continuous or completely intermittent method may also cause a contradiction between temperature control and efficiency. Therefore, a contact-level control method is needed to achieve a constant temperature target and avoid heat peaks and adhesion marks. In one embodiment, in step S5, the first polishing area is polished using an intermittent contact polishing method, with each contact time being 0.3s to 1.5s and the disengagement time being 0.2s to 1.0s, and this process is repeated cyclically. The second polishing area is polished using the same intermittent contact polishing method, with each contact time being 0.5s to 2.0s and the disengagement time being 0.1s to 0.5s. The third polishing area is polished using a continuous contact polishing method. This allows the stress concentration area to obtain a periodic heat dissipation window, further suppressing local temperature rise spikes. Furthermore, by using intermittent contact polishing for the first and second polishing areas and limiting the contact or disengagement time range, the first polishing area is polished with each contact time being 0.3s to 1.5s. The first polishing cycle is 0.2s to 1.0s; the second polishing area is contacted for 0.5s to 2.0s and then removed for 0.1s to 0.5s. At the same time, continuous contact polishing is used for the third polishing area. Pulsed heat input leaves a window for heat dissipation and polishing agent replenishment in the corners and transition areas, suppressing temperature peaks and reducing the risk of adhesion and drag marks. For large areas, where heat dissipation conditions are relatively stable and efficiency is required, continuous contact can be used to increase the mirror forming speed. This can more stably maintain the temperature of the contact area within the target range of 120℃±2℃. Without sacrificing the overall cycle time, it significantly reduces the probability of corner fogging and burns, and improves the gloss consistency between different structural areas.

[0028] In practice, after using partitioned fine polishing and processing in the order of first polishing area to second polishing area and then to third polishing area, two types of problems related to texture direction are likely to occur. First, the second polishing area inherits the fine grinding texture of S4. If the fine polishing trajectory is in the same direction as the grinding texture for a long time, some fine grinding textures may be "carried away along the texture" and remain as a hazy shadow or a brushed feel. Second, partitioned processing can easily produce differences in polishing trajectory and removal amount at the boundary of the area, forming "gloss steps" or "hazy shadow boundaries", affecting the overall mirror surface integrity. To solve this problem, in one embodiment, in step S5, when fine polishing the second polishing area, the polishing trajectory forms a 30° to 90° intersection angle with the grinding texture direction formed by S4 fine grinding, and the polishing of the second polishing area... The light trajectory overlaps with the first and third polishing areas by 5mm to 20mm respectively to eliminate gloss steps and hazy boundaries at the partition boundaries. When fine polishing the second polishing area, the polishing trajectory forms a 30° to 90° intersection angle with the S4 fine grinding texture direction, and the trajectory of the second polishing area overlaps with the first and third polishing areas by 5mm to 20mm respectively. The design purpose is to use the intersection angle to create the effect of "cross cutting or cross polishing", which can more effectively cut off and hide the residual texture of fine grinding. At the same time, by overlapping, the amount of removal and gloss transition at the partition boundary is made into a continuous band, which can significantly weaken the hazy transition band and reduce the sense of boundary steps, making the entire mirror surface more uniform in reflection, especially significantly improving the visibility consistency of bathroom exterior parts under strong light.

[0029] During continuous polishing and zoned fine polishing, metal shavings, oxide particles, and polishing agent residue gradually embed into the surface of the polishing wheel, causing blockage, agglomeration, or localized hard spots. This leads to a shift in the friction state and heat generation level. When switching from the first polishing zone to the second or third polishing zone, changes in parameters, hardness bands, or contact states make the embedded material more likely to randomly scratch the workpiece or cause trailing. These defects are often sporadic and difficult to eliminate stably by simply adjusting v, p, and q. Therefore, in one embodiment, in step S5, when switching from the first polishing zone to the second polishing zone or from the second polishing zone to the third polishing zone, the polishing wheel is continuously supplied with polishing agent... Simultaneously, the polishing wheel contacts the dressing block for 1 to 10 seconds to remove metal chips and polishing agent residue embedded in the polishing wheel, thereby stabilizing the surface condition and frictional heat generation level of the polishing wheel and improving the consistency of constant temperature fine polishing. When switching areas, the polishing wheel is required to contact the dressing block for 1 to 10 seconds while continuously supplying polishing agent to remove metal chips and polishing agent residue embedded in the polishing wheel. Through short-term dressing, the openness and uniformity of the wheel surface are restored, so that the coefficient of friction, cutting or polishing ability and heat generation level return to a controllable state, reducing random scratches and drag marks, reducing the drift risk of "the polishing gets hotter or more foggy as it is polished", and making the temperature control of constant temperature zone fine polishing more stable and the parameter reproducibility better, thereby improving the yield and appearance consistency of mass production.

[0030] After completing the fine polishing of the first, second, and third polishing areas and performing transition zone crossing and overlapping treatments, the entire product may still have issues such as "micro-haze" or "minor inconsistencies in overall gloss." This is because the partitioning process essentially uses different speeds, pressures, supply amounts, and contact methods in different areas. Although this can stabilize the temperature within the target range and prevent burns, under high-requirement mirror finish conditions, the degree of microscopic plastic polishing, micro-residual film layers, and micro-textures in different areas may still have slight differences. Especially under strong light or wide viewing angles, this can manifest as incomplete uniformity in overall mirror clarity. To address this, in one embodiment, after completing the fine polishing of the first, second, and third polishing areas, a full-coverage finishing polishing step is added in step S5: the surface to be polished is fully covered during finishing polishing, with a polishing linear speed of v0 satisfying v0≥v3, a polishing contact pressure of p0 satisfying p0<p1, and a polishing agent supply amount of q0. To further eliminate micro-haze and unify mirror clarity and gloss consistency, a full-coverage finishing step is added after the three-zone fine polishing. During finishing, the linear speed v0 is limited to v0≥v3, the contact pressure p0 is limited to p0<p1, and the polishing agent supply q0 is limited to q3≤q0≤q2, while the working temperature is still maintained at 120℃±2℃. The key design is to use a combination of "higher linear speed and lower pressure" to achieve light-load rapid polishing with "finishing or uniform polishing" as the main function. This makes the mirror reflection of the entire surface more uniform at the micro level. At the same time, the appropriate amount of polishing agent is used to maintain lubrication and temperature stability, avoid dry friction heat generation at high speed or excessive polishing agent residue, which can further eliminate micro-haze, unify mirror clarity and gloss consistency, reduce the risk of regional differences in appearance inspection, and improve the process yield from "basic qualified" to the target level of "high consistency and high gloss" for bathroom appearance parts.

[0031] Working principle and usage process of this invention: Achieving high-gloss finish on aluminum materials through a core process of constant-temperature zoned fine polishing involves several steps. First, the aluminum parts are deburred, cleaned, and progressively ground to create a uniform base. Then, in the fine polishing stage, the polishing compound is preheated and kept at 120℃±2℃ and continuously supplied to the polishing wheel. Simultaneously, based on the geometric curvature and edge characteristics, the surface to be polished is divided into three zones: the first polishing zone, the second polishing zone, and the third polishing zone. The polishing linear speed and contact pressure are matched with increasing and decreasing polishing compound supply for each zone, ensuring that each zone obtains suitable thermal-mechanical-lubricating conditions under constant-temperature constraints. This suppresses local overheating and eliminates defects such as adhesion, drag marks, and haze. After fine polishing, the surface is cleaned and protected, ultimately resulting in a highly consistent mirror-like finish.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-gloss polishing process for aluminum materials, characterized in that, Includes the following steps: S1: Pre-treatment, deburring and shaping of semi-finished aluminum materials, followed by degreasing, cleaning, rinsing and drying; S2: Rough grinding and leveling, using coarse-grained abrasive to rough grind the surface of the semi-finished aluminum material to be polished, in order to remove extrusion marks, tool marks, dents and obvious scratches; S3: Medium grinding and finishing, using medium-sized abrasive to perform medium grinding on the surface after coarse grinding, in order to eliminate coarse grinding marks and obtain a uniform substrate; S4: Fine grinding refinement, using fine-grained abrasive to fine grind the surface after intermediate grinding in order to further reduce surface roughness; S5: Constant Temperature Zoned Polishing. The polishing agent is preheated and maintained at 120℃±2℃. During the polishing process, the polishing agent is continuously supplied to the polishing surface of the polishing wheel, maintaining the working temperature of the polishing contact area between the polishing wheel and the semi-finished aluminum material at 120℃±2℃. Simultaneously, the surface to be polished is divided into a first polishing area, a second polishing area, and a third polishing area according to the geometric edges and the degree of curved surface transition. The first polishing area is for corners, openings, or small rounded corner transitions; the third polishing area is for large flat areas or large arcs; and the second polishing area is located within the first… Between the polishing area and the third polishing area; the first polishing area, the second polishing area and the third polishing area are finely polished in sequence, and the polishing linear speeds corresponding to the first polishing area, the second polishing area and the third polishing area are v1, v2 and v3 respectively, satisfying v1 < v2 < v3, the corresponding polishing contact pressures are p1, p2 and p3 respectively, satisfying p1 < p2 < p3, and the corresponding polishing agent supply amounts are q1, q2 and q3 respectively, satisfying q1 ≥ q2 ≥ q3, so that the working temperature of the polishing contact area of ​​each polishing area is maintained at 120℃ ± 2℃; S6: Post-cleaning and surface treatment: Cleaning and drying the semi-finished aluminum material after fine polishing, and then performing subsequent surface protection treatment. In step S5, the polishing wheel is integrally provided with a first polishing belt, a second polishing belt, and a third polishing belt along the axial direction, and the compressive hardness of the three belts satisfies the condition that the first polishing belt < the second polishing belt < the third polishing belt; in S5, the first polishing belt, the second polishing belt, and the third polishing belt are used to perform fine polishing on the first polishing area, the second polishing area, and the third polishing area, respectively. After completing the fine polishing of the first, second, and third polishing areas, a full-coverage finishing step is added in step S5: the surface to be polished is fully covered and polished. During finishing, the polishing linear speed is v0 and satisfies v0≥v3, the polishing contact pressure is p0 and satisfies p0<p1, the polishing agent supply is q0 and satisfies q3≤q0≤q2, and the working temperature is maintained at 120℃±2℃.

2. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, the first polishing area includes corners, the periphery of orifices, or narrow edges with a feature width W ≤ 10mm on the surface to be polished with a radius of curvature R ≤ 3mm; the third polishing area includes large arcs or planar areas with a radius of curvature R ≥ 10mm on the surface to be polished; and the second polishing area is a transition area with a radius of curvature satisfying 3mm < R < 10mm.

3. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, the polishing linear velocity satisfies: v2 = (1.2~1.6)·v1, v3 = (1.2~1.6)·v2; the polishing contact pressure satisfies: p2 = (1.3~2.0)·p1, p3 = (1.3~2.0)·p2; and the polishing agent supply amount satisfies: q2 = (0.6~0.9)·q1, q3 = (0.6~0.9)·q2.

4. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, before fine polishing the first polishing area, the polishing wheel is idled and polishing agent at a temperature of 120℃±2℃ is continuously supplied for 10s to 60s to form a continuous wetting layer on the polishing surface of the polishing wheel. Then, fine polishing is performed sequentially on the first polishing area, the second polishing area, and the third polishing area.

5. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, the first polishing area is polished by intermittent contact, with each contact time being 0.3s to 1.5s and the detachment time being 0.2s to 1.0s, and the process is repeated cyclically. The second polishing area is polished by intermittent contact, with each contact time being 0.5s to 2.0s and the detachment time being 0.1s to 0.5s. The third polishing area is polished by continuous contact.

6. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, when the second polishing area is finely polished, the polishing trajectory forms a 30° to 90° intersection angle with the grinding pattern direction formed by the fine grinding in S4, and the polishing trajectory of the second polishing area overlaps with the first polishing area and the third polishing area by 5mm to 20mm respectively.

7. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, In step S5, when switching from the first polishing area to the second polishing area, or from the second polishing area to the third polishing area, the polishing wheel is in contact with the dressing block for 1s to 10s while continuously supplying polishing agent to remove metal chips and polishing agent residue embedded in the polishing wheel.

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