High-finish-degree polishing process for aluminum material

Abstract

The invention relates to a high-finish-degree polishing process for aluminum products, and belongs to the technical field of polishing of semi-finished aluminum parts of sanitary products. Constant-temperature constraint and partition correlation parameters are introduced in the fine polishing stage to directly control the thermal state of a polishing contact area; on one hand, a polishing agent is preheated, the temperature is kept at 120 + / -2 DEG C, and the polishing agent is continuously supplied to a polishing wheel in the fine polishing process, so that a lubricating or heat exchange medium with stable temperature is continuously obtained in a polishing contact area, and random fluctuation of heat generated by friction is weakened from the source, and on the other hand, the to-be-polished surface of the complex aluminum part is divided into three areas according to the geometric edge and the curved surface transition degree; the gradient relation of the linear speed, the contact pressure and the polishing agent supply amount is configured, so that corner orifice areas which are prone to stress concentration and instant overheating are matched with the high supply amount at the low speed and the low pressure to obtain higher lubrication and heat stability, and the defects of adhesion, drag marks, fogging, uneven gloss and the like caused by local overheating are reduced; the appearance consistency is improved; and the rework rate is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polishing of semi-finished aluminum parts of bathroom products, and particularly relates to an aluminum material high-surface-finish polishing process. BACKGROUND

[0002] In the field of bathroom products, in order to obtain a high-surface-finish surface of an aluminum profile or an aluminum alloy appearance part, a semi-finished aluminum part is usually subjected to surface treatment by combining mechanical grinding and polishing. The existing process generally includes the following steps: after deburring and oil removal and cleaning of the aluminum part, rough grinding, medium grinding and fine grinding are sequentially performed to gradually eliminate extrusion marks, tool marks and grinding marks, and then pre-polishing and fine polishing are performed by using a polishing wheel in cooperation with a polishing agent, so that a higher mirror surface reflection effect is obtained. After polishing, cleaning is performed to remove polishing residues, and surface protection treatment such as anodic oxidation, electrophoresis or coating is performed according to product requirements.

[0003] However, the semi-finished aluminum part in the bathroom field often has complex structures such as corners, orifices, narrow edges and curved surface transitions, and part of the semi-finished aluminum part is a thin-walled or hollow profile. During contact between the polishing wheel and the workpiece, the following situations are prone to occur: a large change in contact area, local load concentration and unstable heat dissipation path, so that the frictional heat of the polishing contact area presents localized and instantaneous characteristics. In the existing process, the polishing section relies on fixed beats or the experience of operators to adjust the pressure, speed and wax or paste supplementing, and the cooling and heat dissipation mode is often intermittent or extensive, so that the temperature of the polishing contact area is difficult to keep stable. Once the local temperature is too high, appearance defects such as adhesion, scratches, fogging, uneven brightness and slight scratches are easily caused on the surface of the aluminum material, thereby increasing the rework rate and reducing the consistency and yield of the finished product. SUMMARY

[0004] To solve the above problems in the prior art, the application provides an aluminum material high-surface-finish polishing process, which solves the problem that, in the high-surface-finish polishing stage of a semi-finished aluminum material in the bathroom field, the temperature of the polishing contact area is difficult to stabilize, local instantaneous overheating or temperature drift occurs, appearance defects such as adhesion, scratches, fogging and uneven brightness are caused on the surface of the aluminum material, and the consistency is poor, the rework rate is high and the yield of the finished product is reduced.

[0005] The object of the application can be achieved by the following technical solutions. An aluminum material high-surface-finish polishing process, comprising the following steps: S1: pretreatment, deburring and shaping of a semi-finished aluminum material, and oil removal cleaning, rinsing and drying; S2: rough grinding and leveling, rough grinding of a surface to be polished of the semi-finished aluminum material by using coarse-grit abrasive to remove extrusion marks, tool marks, dents and obvious scratches; S3: medium grinding and finishing, medium grinding of the surface after rough grinding by using medium-grit abrasive to eliminate rough grinding marks and obtain a uniform substrate; S4: fine grinding, using fine abrasive to fine grind the surface after center grinding to further reduce the surface roughness; S5: constant temperature partition fine polishing, preheating and keeping the polishing agent at 120℃±2℃, continuously supplying the polishing agent to the polishing surface of the polishing wheel in the fine polishing process, keeping the working temperature of the polishing contact area formed by the polishing wheel and the semi-finished aluminum product at 120℃±2℃, and dividing the surface to be polished into a first polishing area, a second polishing area and a third polishing area according to geometric edges and the degree of curvature surface transition, wherein the first polishing area is an edge corner, an orifice or a small round corner transition part, the third polishing area is a large area plane or a large arc part, and the second polishing area is located between the first polishing area and the third polishing area; fine polishing is sequentially performed on the first polishing area, the second polishing area and the third polishing area, and the corresponding polishing linear velocities of the first polishing area, the second polishing area and the third polishing area are v1, v2 and v3 respectively and satisfy v1 S6: post-cleaning and surface treatment, cleaning and drying the semi-finished aluminum product after fine polishing, and performing subsequent surface protection treatment.

[0006] As a further scheme of the present application, in step S5, the first polishing area includes an edge corner, an orifice periphery or a narrow edge part with a feature width W≤10mm in the surface to be polished with a radius of curvature R≤3mm; the third polishing area includes a large arc part or a plane part in the surface to be polished with a radius of curvature R≥10mm; and the second polishing area is a transition part with a radius of curvature satisfying 3mm

[0007] As a further scheme of the present application, in step S5, the polishing linear velocities satisfy v2=(1.2-1.6)·v1 and v3=(1.2-1.6)·v2, the polishing contact pressures satisfy p2=(1.3-2.0)·p1 and p3=(1.3-2.0)·p2, and the polishing agent supply amounts satisfy q2=(0.6-0.9)·q1 and q3=(0.6-0.9)·q2, so that the heat input, lubrication and heat exchange conditions of the three polishing areas are progressively matched.

[0008] As a further scheme of the present application, in step S5, the single polishing contact times of the first polishing area, the second polishing area and the third polishing area during fine polishing are t1, t2 and t3 respectively, which satisfy t1≥t2≥t3 and further satisfy 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 action intensity of different regions under the constant temperature constraint is coordinated with the supply lubrication, thereby inhibiting local overheating and gloss difference.

[0009] As a further scheme of the present application, in step S5, before fine polishing of the first polishing region, the polishing wheel is idled and polishing agent at a temperature of 120℃±2℃ is continuously supplied for 10s-60s, so that a continuous wetting layer is formed on the polishing surface of the polishing wheel, and then fine polishing is performed in sequence for the first polishing region, the second polishing region and the third polishing region, so as to reduce the temperature rise peak and drag marks caused by fluctuation of the initial friction coefficient.

[0010] As a further scheme of the present application, in step S5, the polishing wheel is integrally provided with the first polishing belt, the second polishing belt and the third polishing belt along the axial direction, and the compression hardnesses of the three satisfy first polishing belt<second polishing belt<third polishing belt; in S5, the first polishing region, the second polishing region and the third polishing region are fine polished by the first polishing belt, the second polishing belt and the third polishing belt respectively, so as to realize partition heat-force matching by structural difference of the same polishing wheel.

[0011] As a further scheme of the present application, in step S5, for the first polishing region, intermittent contact polishing is adopted, the contact time is 0.3s-1.5s each time, the separation time is 0.2s-1.0s and the cycle is repeated, for the second polishing region, the contact time is 0.5s-2.0s each time in the intermittent contact polishing, the separation time is 0.1s-0.5s, and for the third polishing region, continuous contact polishing is adopted, so as to obtain periodic heat dissipation window for the stress concentration region and further inhibit local temperature rise peak.

[0012] As a further scheme of the present application, in step S5, when the second polishing region is fine polished, the polishing track forms a crossing angle of 30°-90° with respect to the grinding direction of the grinding lines formed by S4 fine grinding, and the polishing track of the second polishing region overlaps the first polishing region and the third polishing region by 5mm-20mm respectively, so as to eliminate the gloss step and fog shadow boundary at the partition boundary.

[0013] As a further scheme of the present application, in step S5, when switching from the first polishing region to the second polishing region, or from the second polishing region to the third polishing region, the polishing wheel is contacted with the dressing block for 1s-10s while continuously supplying the polishing agent, so as to discharge the metal chips and polishing agent residues embedded in the polishing wheel, thereby stabilizing the surface state of the polishing wheel and the level of frictional heat generation, and improving the consistency of constant temperature fine polishing.

[0014] As a further scheme of the present application, after the fine polishing of the first polishing area, the second polishing area and the third polishing area is completed, a full-coverage polishing step is added in step S5: full-coverage polishing is performed on the surface to be polished, the polishing linear speed is v0 and v0≥v3 is satisfied, the polishing contact pressure is p0 and p0

[0015] The present application has the following advantages: By introducing constant temperature constraint in the polishing step and combining with the partition-related parameters, the polishing contact area thermal state 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 temperature-stable lubricating or heat exchange medium, and the random fluctuations of friction heat generation are weakened from the source; on the other hand, the surface to be polished is divided into three types of areas according to the geometric edges and the transition degree of the curved surface, i.e. the first polishing area, the second polishing area and the third polishing area, and the gradients of the linear speed v, the contact pressure p and the polishing agent supply q of the three types of areas are set and interconnected, v1 BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to facilitate those skilled in the art to understand, the present application will be further described below in conjunction with the drawings.

[0017] Figure 1 The present application is an aluminum high-finish polishing process flow chart. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in conjunction with the drawings and preferred embodiments.

[0019] Please refer to Figure 1 The present embodiment provides an aluminum high-finish polishing process, which comprises the following steps: S1: pretreatment, deburring and shaping of the semi-finished aluminum product, and oil removal cleaning, rinsing and drying; S2: rough grinding and leveling, rough grinding the surface to be polished of the semi-finished aluminum product with coarse abrasive to remove extrusion marks, tool marks, dents and obvious scratches; S3: medium grinding and finishing, medium grinding the surface after rough grinding with medium abrasive to eliminate rough grinding marks and obtain a uniform base; S4: fine grinding and detailing, fine grinding the surface after medium grinding with fine abrasive to further reduce the surface roughness; S5: constant temperature zoned precision polishing, preheating and maintaining the polishing agent at 120℃±2℃, continuously supplying the polishing agent to the polishing surface of the polishing wheel during the precision polishing process, maintaining the working temperature of the polishing contact area formed by the polishing wheel and the semi-finished aluminum product at 120℃±2℃, and dividing the surface to be polished into a first polishing area, a second polishing area and a third polishing area according to geometric edges and the degree of curvature transition, wherein the first polishing area is the edge, aperture or small round corner transition part, the third polishing area is the large area flat surface or large round arc part, and the second polishing area is located between the first polishing area and the third polishing area; sequentially polishing the first polishing area, the second polishing area and the third polishing area, and the corresponding polishing line speeds of the first polishing area, the second polishing area and the third polishing area are v1, v2 and v3 respectively and satisfy v1 S6: post-cleaning and surface treatment, cleaning and drying the semi-finished aluminum product after precision polishing, and performing subsequent surface protection treatment.

[0020] Based on the high-temperature polishing stage of semi-finished aluminum products in the field of bathroom in the prior art, the temperature of the polishing contact area is difficult to stabilize, and local transient overheating or temperature drift occurs, thereby causing appearance defects such as adhesion, drag marks, fogging and uneven gloss on the surface of the aluminum product, resulting in poor consistency, high rework rate and low yield. An embodiment is provided, which directly controls the thermal state of the polishing contact area by introducing constant temperature constraints and partition correlation parameters in the fine polishing stage. On the one hand, the polishing agent is preheated and kept at 120℃±2℃ and continuously supplied to the polishing wheel during fine polishing, so that the polishing contact area continuously obtains temperature-stable lubrication / heat exchange medium, thereby weakening the random fluctuations of friction heat generation from the source. On the other hand, the surface to be polished of the complex aluminum part is divided into a first polishing area, a second polishing area and a third polishing area according to the geometric edges and the transition degree of the curved surface, and the gradient relationship of the linear velocity, the contact pressure and the polishing agent supply amount is configured respectively, v1

[0021] It should be noted that the combination of pre-treatment, step-by-step grinding, constant temperature partition fine polishing, post-cleaning and surface treatment is because the high smoothness is not only dependent on the final fine polishing, but also dependent on the step-by-step elimination of extrusion marks, tool marks and grinding marks by the previous processes to build a uniform base. In the fine polishing stage, which is the most likely to be thermally unstable due to complex structure, by embedding temperature control into process constraints, the polishing agent is supplied at a constant temperature and continuously, the contact area temperature is kept at 120℃±2℃, and the speed, pressure and polishing agent supply amount are configured according to the geometric sensitivity degree, the operation can be changed from relying on experience to waxing according to gloss and feeling to a replicable parameter system. The direct benefits are: the heat input in the fine polishing stage is more controllable, the lubrication is more stable, the edge and corner openings are less likely to be burned or dragged, the polishing efficiency of large area is improved and the overall gloss is more uniform, thereby significantly improving the yield and batch consistency, and providing a more stable high smoothness base for subsequent anodizing, electrophoresis or coating surface protection treatment.

[0022] Since the first polishing area, the second polishing area and the third polishing area are divided according to the geometric edges and the transition degree of curved surfaces, the problem of inconsistent partition standards may still occur in actual production. Different operators, different batches or different product models may have different understandings of "edges, small fillets, transitions, large fillets / planes". Especially for the narrow edges, orifice perimeters and local transition zones commonly seen on bathroom aluminum parts, if there is a lack of quantifiable judgment basis, the stress concentration area may be misjudged as a large area and higher speed or pressure is applied, resulting in local transient overheating, fogging or drag marks. On the contrary, misjudging a large area as an edge area will cause efficiency to decline, brightness to be insufficient and the beat to be out of control. In order to solve this problem, in an embodiment, in step S5, the first polishing area includes edges, orifice perimeters or narrow edge parts with a feature width W≤10mm in the polishing surface with a curvature radius R≤3mm; the third polishing area includes large fillet parts or plane parts with a curvature radius R≥10mm in the polishing surface; and the second polishing area is a transition part with a curvature radius satisfying 3mm

[0023] Further, although the above-mentioned three types of regions are defined to satisfy the directional relationship of "v1 < v2 < v3, p1 < p2 < p3, q1 ≥ q2 ≥ q3", in actual landing, the problem of "unreasonable gradient amplitude" may still occur. If the increase amplitude of v and p is too small, the difference between the three regions is not enough to offset the load concentration and poor heat dissipation caused by geometry, and the edge and corner regions may still be overheated due to higher local friction work density. If the increase amplitude is too large, it will cause the heat input of the second and third regions to increase sharply or be polished too quickly, resulting in fogging, smearing or brightness jump. In addition, if the decrease amplitude of q is not matched, it will also lead to insufficient lubrication. Therefore, a more controllable proportion range is needed on top of the size rule to avoid the randomness of parameter selection. To this end, in an embodiment, in step S5, the polishing linear speed 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; 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 regions is progressively matched with the lubrication and heat exchange conditions. Here, the gradient of each region parameter is constrained by the multiple interval, and the design logic is to map the geometric difference between the regions into a gentle but sufficient process gradient. The speed and pressure are gradually increased to improve the polishing efficiency and mirror forming capability of the transition area and large area, while the polishing agent supply amount is gradually reduced to avoid splashing, mushing or surface residue in the large area due to excessive polishing agent. At the same time, the interval limit prevents the lubrication from being suddenly reduced. The advantage is that the process is more easily scaled by v1, p1 and q1 as the reference on different equipment and different product sizes to achieve rapid calibration, taking into account efficiency and thermal stability, reducing parameter adjustment time and reducing local overheating or uneven gloss caused by out-of-control parameter span.

[0024] Further, after the gradient relationship of speed, pressure and supply amount has been established, there is still a key variable, which is the polishing contact time. Polishing contact time will destroy temperature stability and gloss consistency. The edge and corner hole regions of bathroom aluminum parts usually need more detailed processing to eliminate fine scratches and edge fogging. Operators often increase the residence or repeated contact, while large area regions tend to move quickly. If there is no correlation constraint between contact time and supply amount, speed and pressure, even if v, p and q are set reasonably, the edge and corner may be overheated due to insufficient supply for too long time, or steps and fogging may occur in the transition area or boundary due to insufficient polishing for too short time. In order to avoid this problem, in an embodiment, in step S5, when the first polishing region, the second polishing region and the third polishing region are fine polished, the single polishing contact time is t1, t2 and t3 respectively, and satisfies t1 ≥ t2 ≥ t3, and further satisfies 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 action intensity of different areas under the constant temperature constraint is coordinated with the supply lubrication, thereby inhibiting local overheating and gloss difference, by limiting the single contact time of each area to meet t1≥t2≥t3, and further coupling the heat input and lubrication supply between v.p.t and q, in other words, it can be understood here that the matching of friction work input and polishing agent supply is controlled in different areas, so that the unit supply amount of each area bears the same level of friction work, the necessity of which is to realize the objective demand that the corners need longer processing under the premise of reducing v and p and increasing q without causing overheating, and the benefits of which are: on the one hand, through the time gradient, the first polishing area is ensured to complete the detail mirrorization under safer thermal conditions, and on the other hand, through the equivalent heat load matching, the temperature drift caused by the difference in residence time between the three areas is reduced, thereby reducing the probability of drag marks, fogging and brightness jump, and improving the uniformity of the overall mirror surface clarity.

[0025] In addition, in actual operation, since it is required that the polishing agent be continuously supplied at 120°C±2°C constant temperature to stabilize the contact area temperature, but at the beginning of actual fine polishing, the polishing surface of the polishing wheel is often in an insufficiently wetted state, and the polishing agent has not yet formed a continuous film layer or a stable carrying state on the wheel surface. When the polishing wheel first contacts the workpiece, the friction coefficient and heat generation will change abruptly, especially when the first polishing area is processed first, which is more prone to instantaneous scratches, fogging or drag marks, causing defects and affecting subsequent consistency. Therefore, the problem of unstable wheel surface state at the initial stage of fine polishing needs to be solved. To this end, in one embodiment, in step S5, before fine polishing the first polishing area, the polishing wheel is first idled and continuously supplied with polishing agent at a temperature of 120°C±2°C for 10s-60s to form a continuous wetting layer on the polishing surface of the polishing wheel, and then fine polishing is performed in the first polishing area, the second polishing area and the third polishing area in turn, so as to reduce the temperature rise peak and drag marks caused by the fluctuation of the initial friction coefficient. The design purpose of the pre-wetting step of idling the polishing wheel and continuously supplying 120°C±2°C polishing agent for 10s-60s before entering the fine polishing of the first polishing area is to form a continuous wetting layer on the polishing surface of the polishing wheel and achieve a more stable friction and heat exchange state before contacting the workpiece. The benefit of this is that fine polishing is under lubricated and temperature controllable working conditions from the first second, which can significantly reduce the initial transient heat peak and the risk of dry friction scratches, reduce the starting drag marks and fog shadows, and make it easier for the subsequent partition parameters to stabilize the contact area temperature within the target range, thereby improving the mirror surface consistency and repeatability of the entire product.

[0026] Although the speed, pressure and supply amount can adjust the heat input and lubrication, the compression hardness of the polishing wheel body also determines the contact area, pressure distribution and local friction work density. If a slightly hard polishing wheel is used in the small fillet area of the corner aperture, the contact area is smaller and the stress is more concentrated, which is easy to cause local overheating and cutting edge scratches. If a slightly soft polishing wheel is used in the large area plane or large arc, it may also cause low mirror forming efficiency and uneven corrugation or brightness due to insufficient support, so only the v, p and q gradients may not be able to simultaneously consider the contact stability and efficiency of the three types of regions. Therefore, in an 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 compression hardness of the three satisfies first polishing belt < second polishing belt < third polishing belt; in S5, the first polishing belt, the second polishing belt and the third polishing belt are used to polish the first polishing region, the second polishing region and the third polishing region respectively, so as to realize the partition heat-power matching through the structural difference of the same polishing wheel. Wherein, the first, second and third polishing belts are integrally provided along the axial direction, and the compression hardness satisfies first polishing belt < second polishing belt < third polishing belt, and are used to correspond to the first, second and third polishing regions respectively. Here, the wheel surface compliance gradient is used to match the geometric sensitivity gradient. The first polishing belt is softer to improve the fitting ability, expand the effective contact area and release the load concentration of the corner aperture. The second polishing belt provides transition support to balance the fitting and efficiency. The third polishing belt is harder to ensure the forming efficiency and mirror clarity of the large area region. This design can stabilize the contact state of each region, reduce local burns or scratches or insufficient brightness caused by hardness mismatch, and further improve the repeatability and beat stability of constant temperature partition fine polishing without significantly increasing the operation complexity.

[0027] Based on the above embodiment, even if v1 and p1 are set to be lower and q1 is increased, the corner aperture region may still have heat accumulation due to poor heat dissipation conditions, small heat capacity, thin-walled structure and other factors. Especially in continuous contact polishing, friction heat will accumulate in a short time to form a local temperature peak value. The second polishing region is a transition zone with geometric and heat dissipation conditions between the two. If a completely continuous or completely discontinuous method is used, it may also cause a contradiction between temperature control and efficiency. Therefore, a contact method level control means is needed to cooperate with the constant temperature target to avoid heat peak value and adhesive scratches, In an embodiment, in step S5, the first polishing area is polished by intermittent contact polishing, the contact time is 0.3s-1.5s and the separation time is 0.2s-1.0s, and the second polishing area is polished by intermittent contact polishing, the contact time is 0.5s-2.0s and the separation time is 0.1s-0.5s, and the third polishing area is polished by continuous contact polishing, so that the stress concentration area obtains a periodic heat dissipation window, and the local temperature rise peak is further suppressed. In addition, by polishing the first and second polishing areas by intermittent contact polishing and limiting the contact or separation time range, the first polishing area is contacted for 0.3s-1.5s and separated for 0.2s-1.0s, the second polishing area is contacted for 0.5s-2.0s and separated for 0.1s-0.5s, and the third polishing area is continuously contacted, the edge and transition area is left a window for heat dissipation and polishing agent replenishment by pulse heat input, the temperature peak is suppressed, the adhesion and drag mark risk is reduced, the large area can be continuously contacted to improve the mirror surface forming speed, the contact area temperature can be more stably maintained in the target range of 120°C±2°C, the edge fogging and burning probability is significantly reduced without sacrificing the overall cycle, and the gloss consistency between different structure areas is improved.

[0028] In actual operation, after processing in the order of the first polishing area to the second polishing area to the third polishing area by partitioned fine polishing, two types of problems related to the texture direction are prone to occur. One is that the second polishing area receives the grinding texture of S4 fine grinding, and if the fine polishing trajectory and the grinding texture direction are in the same direction for a long time, part of the fine grinding texture may be "taken along the grain" and left as a fog shadow or a wire drawing feeling. The second is that partitioned processing is prone to produce differences in polishing trajectory and removal amount at the region boundary, forming "gloss steps" or "fog shadow boundaries", affecting the integrity of the mirror surface. In order to solve this problem, in an embodiment, when fine polishing the second polishing area in step S5, the polishing trajectory forms an intersection angle of 30°-90° with the grinding texture direction formed by S4 fine grinding, and the polishing trajectory of the second polishing area overlaps the first and third polishing areas by 5mm-20mm respectively, so as to eliminate the gloss steps and fog shadow boundaries at the partition boundary. When fine polishing the second polishing area, the polishing trajectory forms an intersection angle of 30°-90° with the grinding texture direction of S4 fine grinding, and the second polishing area trajectory overlaps the first and third polishing areas by 5mm-20mm respectively. The design purpose is to produce the effect of "cross cutting or cross polishing" by the intersection angle, more effectively cutting off and eliminating the fine grinding residual texture, and at the same time, the removal amount and gloss transition at the partition boundary are made into a continuous band by overlapping, which can significantly weaken the transition band fog shadow, reduce the boundary step feeling, and make the whole mirror surface reflection more uniform, especially the visual consistency of the bathroom appearance under strong light is significantly improved.

[0029] As the polishing wheel surface will gradually embed metal chips, oxide particles and polishing agent residues in the process of continuous supply of polishing agent and zoned fine polishing, causing the wheel surface to be blocked or clumped or local hard spots, thus causing the friction state and the level of heat to drift, when switching from the first polishing area to the second polishing area or from the second to the third, due to the change of parameters, hardness band or contact state, the embedded objects are more likely to scratch the workpiece or cause drag in a random way, such defects often have occasionality, and it is difficult to eliminate by adjusting v, p, q alone, for this, in an embodiment, when switching from the first polishing area to the second polishing area, or from the second polishing area to the third polishing area in step S5, the polishing wheel is in contact with the dressing block for 1s-10s while continuously supplying the polishing agent to discharge the metal chips and polishing agent residues embedded in the polishing wheel, thereby stabilizing the polishing wheel surface state and the level of friction and heat generation, improving the consistency of constant temperature fine polishing, and the polishing wheel is in contact with the dressing block for 1s-10s while continuously supplying the polishing agent when switching between areas to discharge the metal chips and polishing agent residues embedded in the polishing wheel, restore the openness and uniformity of the wheel surface by short-time dressing, make the friction coefficient, cutting or polishing ability and heat generation level return to a controllable state, reduce random scratches and drag marks, reduce the risk of "polishing more and more hot or more and more fog" drift, at the same time make the temperature control of constant temperature zoned fine polishing more stable, the parameter reproducibility better, thereby improving the yield and appearance consistency of batch production.

[0030] After the fine polishing of the three types of regions, i.e., the first polishing region, the second polishing region and the third polishing region, and the transition zone intersection and lap processing, the whole product may still have the problem of "micro-fog shadow" or "slight inconsistency of overall gloss", which is due to the fact that the partition process essentially uses different speeds, pressures, supply amounts and contact modes in different regions, although the temperature can be stabilized in the target range and burning can be avoided, but under high requirement mirror surface appearance, the microscopic plastic polishing degree, micro residual film and micro texture of different regions may still have very small differences, especially under strong light or large viewing angle, which will show that the overall mirror surface definition is not completely uniform, and for this, in an embodiment, after the fine polishing of the first polishing region, the second polishing region and the third polishing region, a full-coverage polishing step is added in step S5: full-coverage polishing is performed on the surface to be polished, the polishing line speed is v0 and satisfies v0≥v3, the polishing contact pressure is p0 and satisfies p0

[0031] The working principle and use process of the present application are as follows: The present application realizes high-precision polishing of aluminum materials through the core step of constant-temperature partition fine polishing. First, the aluminum parts are deburred, cleaned and ground step by step to build a uniform base. Then, in the fine polishing stage, the polishing agent is preheated and kept at 120℃±2℃ and continuously supplied to the polishing wheel. At the same time, the surface to be polished is divided into three types of regions, i.e., the first polishing region, the second polishing region and the third polishing region, according to the geometric curvature and edge characteristics, and the polishing line speed and contact pressure are matched with the polishing agent supply amount, respectively, so that each region obtains suitable thermal, mechanical and lubricating conditions under constant temperature constraints, thereby inhibiting local overheating, eliminating adhesion, drag marks and fog shadow defects. After fine polishing, cleaning and surface protection treatment, a high-consistency mirror surface is finally obtained.

[0032] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, as long as the changes or modifications do not deviate from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments made according to the technical essence of the present application still belong to the scope of the technical solution of the present application.

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, removing the polishing agent, and then performing subsequent surface protection treatment.

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, when the first, second, and third polishing areas are finely polished, the single polishing contact times are t1, t2, and t3, respectively, and satisfy t1≥t2≥t3, and further satisfy 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.

5. 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.

6. The high-gloss polishing process for aluminum materials according to claim 1, characterized in that, 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.

7. 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.

8. 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.

9. 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.

10. The high-gloss polishing process for aluminum materials according to claim 6, characterized in that, 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℃.

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