A processing technique for microcrystalline glass

Abstract

The present application relates to the technical field of glass-ceramics, and particularly relates to a processing technology of glass-ceramics, comprising the following steps: (1) CNC processing; (2) scanning body; (3) scanning 2.5D surface; (4) double-sided polishing; (5) strengthening; (6) polishing body; (7) polishing 2.5D surface. The processing technology of the present application optimizes the finishing cutting amount by adjusting the processing program in the CNC processing step, reduces the probability of micro-cracks caused by large cutting amount of the grinding head; increases the grinding amount by adjusting the time in the scanning 2.5D surface step, improves the effect of arc polishing, reduces the scratches on the surface of the glass, and improves the strength of the glass; increases the grinding amount by adjusting the time in the double-sided polishing step, improves the flatness of the glass, reduces the scratches on the surface of the glass, and improves the strength of the glass; and increases the body and surface return polishing after strengthening, reduces the scratches on the surface and the periphery of the glass, micro-cracks and salt particles attached to the surface after strengthening, and improves the overall strength of the glass.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microcrystalline glass, and particularly relates to a processing technology of microcrystalline glass. BACKGROUND

[0002] At present, in order to improve the scratch resistance and drop resistance of the glass cover plate, the glass is usually strengthened to prepare a strengthened glass. Introducing surface compressive stress on the glass surface is a common method for strengthening the glass. The method for introducing surface compressive stress can be realized by physical or chemical methods, so it can be divided into physical strengthening method and chemical strengthening method. Among them, the chemical strengthening method is also called ion exchange method, and the main process is to immerse the glass into an alkali ion molten salt for ion exchange. Since the radius of the alkali metal ion in the alkali ion molten salt is larger than that of the alkali metal ion in the glass, when the two kinds of alkali metal ions are ion exchanged, the "jamming" effect of the alkali metal ion with larger radius is generated on the glass surface, so that a certain depth of compressive stress layer is formed on the glass surface. The compressive stress layer can improve the surface hardness of the glass to a certain extent, resist external impact and prevent the expansion of micro-cracks, thereby improving the scratch resistance and drop resistance of the glass.

[0003] However, with the increasing size of the display screen of mobile electronic devices, the risk of glass cover plate falling and breaking is getting higher and higher. Therefore, the existing conventional glass cover plate made of alkali-aluminosilicate glass by chemical strengthening is difficult to meet the actual application requirements.

[0004] In view of the better mechanical properties of microcrystalline glass compared with alkali-aluminosilicate glass, the industry attempts to use microcrystalline glass as raw material glass for chemical strengthening in order to obtain a glass cover plate with scratch resistance and drop resistance that can meet the current demand. The CNC machining and polishing of the existing microcrystalline glass will cause micro-cracks on the surface and the whole body of the glass, resulting in low yield and reducing the strength of the microcrystalline glass. SUMMARY

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present application is to provide a processing technology of microcrystalline glass.

[0006] The purpose of the present application is achieved by the following technical scheme: a processing technology of microcrystalline glass, comprising the following steps:

[0007] (1) CNC machining: the glass is machined in shape and hole carving by CNC, and the CNC finishing cutting amount is 0.03-0.05mm per single tool;

[0008] (2) scanning the body: the glass is overlapped and the body around the glass is scanned and polished;

[0009] (3) 2.5D surface scanning: the edge-scanned glass sheet is placed on a base, and then the 2.5D surface of the glass is scanned, and the scanning time is 10-14 min;

[0010] (4) double-sided polishing: the 2.5D surface and the back surface of the glass are polished; the polishing time is 50-70 min;

[0011] (5) strengthening: the glass is chemically strengthened;

[0012] (6) polishing the body: the glass is overlapped, and the body around the glass is polished;

[0013] (7) polishing the 2.5D surface: the edge-scanned glass sheet is placed on a base, and then the 2.5D surface of the glass is polished.

[0014] Preferably, in the step (1), the process parameters of the CNC machining are as follows: the spindle motor speed is 36000-40000 r / min, two roughing processes are performed first, and then four finishing processes are performed; the roughing process adopts a grinding head with a surface plated with diamond grits of 400-600 mesh, the straight edge speed is 700-900 mm / min, the corner speed is 200-400 mm / min, and the feeding amount of the two roughing processes is 0.15-0.19 mm; the finishing process adopts a grinding head with a surface plated with diamond grits of 800-1200 mesh, the straight edge speed is 200-400 mm / min, the corner speed is 200-400 mm / min, and the feeding amount of the four finishing processes is 0.03-0.05 mm, and the total machining time is 16-24 min. More preferably, the process parameters of the CNC machining are as follows: the spindle motor speed is 38000 r / min, two roughing processes are performed first, and then four finishing processes are performed; the roughing process adopts a grinding head with a surface plated with diamond grits of 500 mesh, the straight edge speed is 800 mm / min, the corner speed is 300 mm / min, and the feeding amount of the two roughing processes is 0.17 mm; the finishing process adopts a grinding head with a surface plated with diamond grits of 1000 mesh, the straight edge speed is 300 mm / min, the corner speed is 300 mm / min, and the feeding amount of the four finishing processes is 0.04 mm, and the total machining time is 18 min.

[0015] Preferably, in the step (2), the process parameters of the body scanning are as follows: the brush rotation speed is 900-1200 / min, the powder concentration is 1.0-1.4 g / mL, the single side grinding amount is 0.01-0.03 mm, the feeding speed is 200-280 mm / min for the short side, 220-300 mm / min for the long side, 1000-1200 mm / min for the four R angles, the polishing is performed by mixing pig hair and abrasive strips, and the polishing time is 50-70 min. More preferably, the process parameters of the body scanning are as follows: the brush rotation speed is 1050 / min, the powder concentration is 1.2 g / mL, the single side grinding amount is 0.02 mm, the feeding speed is 240 mm / min for the short side, 260 mm / min for the long side, 1150 mm / min for the four R angles, the polishing is performed by mixing pig hair and abrasive strips, and the polishing time is 60 min.

[0016] Preferably, in the step (3), the process parameters of the 2.5D surface scanning are as follows: the rotation speed is 30-50 r / min, the positive and negative are each 2 times, the pressure is 30-50 Kg, the current is 20-24 A, the polishing is performed by using a blanket, and the polishing time is 10-14 min. More preferably, the process parameters of the 2.5D surface scanning are as follows: the rotation speed is 40 r / min, the positive and negative are each 2 times, the pressure is 40 Kg, the current is 20-24 A, the polishing is performed by using a blanket, and the polishing time is 12 min.

[0017] Preferably, in the step (4), the process parameters of the double-sided polishing are as follows: the upper disc rotation speed is 12-18 r / min, the lower disc rotation speed is 20-28 r / min, the pressure is 300-400 kg, the powder concentration is 1.0-1.2 g / mL, the upper and lower polishing are both performed by using white abrasive skin with a thickness of 3-5 mm, and the polishing time is 50-70 min. More preferably, the process parameters of the double-sided polishing are as follows: the upper disc rotation speed is 15 r / min, the lower disc rotation speed is 24 r / min, the pressure is 350 kg, the powder concentration is 1.1 g / mL, the upper and lower polishing are both performed by using white abrasive skin with a thickness of 4 mm, and the polishing time is 60 min.

[0018] Preferably, the step (5) is specifically as follows: the microcrystalline glass is placed into a mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, and is strengthened at a temperature of 450-470℃ for 410-430 min to obtain the strengthened microcrystalline glass; wherein the mass ratio of the potassium nitrate and the sodium nitrate is 6-8:2-4, and the content of the lithium nitrate is 0.2wt%-0.4wt%. More preferably, the microcrystalline glass is placed into a mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, and is strengthened at a temperature of 460℃ for 7 h to obtain the strengthened microcrystalline glass; wherein the mass ratio of the potassium nitrate and the sodium nitrate is 7:3, and the content of the lithium nitrate is 0.3wt%.

[0019] Preferably, in the step (6), the polishing process parameters of the body are as follows: the brush rotation speed is 900-1200 / min, the polishing powder concentration is 1.0-1.4 g / mL, the feeding speed is 200-280 mm / min for the short side, 220-300 mm / min for the long side, 1000-1200 mm / min for the four R corners, the polishing time is 1.5-2.5 min, and the polishing is performed by using a mixture of pig hair and abrasive strips. More preferably, the polishing process parameters of the body are as follows: the brush rotation speed is 1050 / min, the polishing powder concentration is 1.2 g / mL, the feeding speed is 240 mm / min for the short side, 260 mm / min for the long side, 1150 mm / min for the four R corners, and the polishing time is 2 min.

[0020] Preferably, in the step (7), the 2.5D face polishing process parameters are as follows: the upper disc rotation speed is 12-18 r / min, the lower disc rotation speed is 20-28 r / min, the pressure is 250-350 kg, the polishing powder concentration is 1.0-1.2 g / mL, the upper polishing is performed by using a carpet, the lower polishing is performed by using an abrasive, and the polishing time is 2-6 min. More preferably, the 2.5D face polishing process parameters are as follows: the upper disc rotation speed is 15 r / min, the lower disc rotation speed is 24 r / min, the pressure is 350 kg, the polishing powder concentration is 1.1 g / mL, the upper polishing is performed by using a carpet, the lower polishing is performed by using an abrasive, and the polishing time is 6 min.

[0021] Preferably, the crystalline phase content of the glass-ceramic is 40wt%-50wt%, the crystalline phase is lithium disilicate and petalite, and the average particle size of the crystalline phase is 30-70 nm. More preferably, the crystalline phase content of the glass-ceramic is 45wt%, and the average particle size of the crystalline phase is 50 nm.

[0022] Preferably, the thermal expansion ratio of the glass-ceramic is 70*10 -7 -75*10 -7 / ℃, the Young's modulus is 96.5-101.2 Mpa, the transmittance is 90%-93%, the haze is ≤0.16%, and the Vickers hardness is 700-740. More preferably, the thermal expansion ratio of the glass-ceramic is 72.2*10 -7 / ℃, the Young's modulus is 98.8 Mpa, the transmittance is 91.3%, the haze is ≤0.16%, and the Vickers hardness is 722.

[0023] The processing technology has the beneficial effects that: the processing technology optimizes the finishing cutting amount by adjusting the processing program in the CNC processing step, reduces the probability of micro-cracks caused by large cutting amount of the grinding head; the processing technology increases the grinding amount by adjusting the time in the 2.5D surface scanning step, improves the arc polishing effect, reduces the scratches on the glass surface, and improves the glass strength; the processing technology increases the grinding amount by adjusting the time in the double-sided polishing step, improves the flatness of the glass and reduces the scratches on the glass surface, and improves the glass strength; and the processing technology reduces the scratches on the glass surface and the periphery, the micro-cracks and the salt particles attached to the surface after strengthening, and improves the overall strength of the glass by increasing the body polishing and surface polishing after strengthening. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of those skilled in the art, the present application will be further described below in conjunction with examples, and the content mentioned in the embodiments is not a limitation of the present application.

[0025] Example 1

[0026] A processing technology of microcrystalline glass, comprising the following steps:

[0027] (1) CNC processing: the glass is processed in shape and hole position by CNC, and the CNC finishing cutting amount is 0.03mm for single tool;

[0028] (2) scanning the body: the glass is overlapped, and the body around the glass is scanned;

[0029] (3) scanning 2.5D surface: the glass single piece after scanning the edge is placed on the base, and then the 2.5D surface of the glass is scanned, and the scanning time is 10min;

[0030] (4) double-sided polishing: the 2.5D surface and the back surface of the glass are polished; the polishing time is 50-70min;

[0031] (5) strengthening: the glass is chemically strengthened;

[0032] (6) polishing the body: the glass is overlapped, and the body around the glass is polished;

[0033] (7) polishing 2.5D surface: the glass single piece after scanning the edge is placed on the base, and then the 2.5D surface of the glass is polished.

[0034] In the step (1), the process parameters of the CNC machining are as follows: the spindle motor speed is 36000 r / min, two roughing is firstly performed, and then four finishing is performed; the roughing is performed by using the grinding head with the surface plated with the diamond grit of 400 mesh, the straight edge speed is 700 mm / min, the corner speed is 200 mm / min, and the feeding amount of the two roughing is 0.15 mm; the finishing is performed by using the grinding head with the surface plated with the diamond grit of 800 mesh, the straight edge speed is 200 mm / min, the corner speed is 200 mm / min, the feeding amount of the four finishing is 0.03 mm, and the total processing time is 16 min.

[0035] In the step (2), the process parameters of the body scanning polishing are as follows: the brush speed is 900 / min, the grinding powder concentration is 1.0 g / mL, the single side grinding amount is 0.01 mm, the feeding speed is 200 mm / min for the short side, 220 mm / min for the long side, and 1000 mm / min for the four R corners, the polishing is performed by using the mixed pig hair and grinding leather, and the polishing time is 50 min.

[0036] In the step (3), the process parameters of the 2.5D surface scanning polishing are as follows: the speed is 30 r / min, the positive and negative is each 2 times, the pressure is 30 Kg, the current is 20 A, the polishing is performed by using the blanket, and the polishing time is 10 min.

[0037] In the step (4), the process parameters of the double-sided polishing are as follows: the upper disc speed is 12 r / min, the lower disc speed is 20 r / min, the pressure is 300 kg, the grinding powder concentration is 1.0 g / mL, the upper and lower polishing are both performed by using the white grinding leather with the thickness of 3 mm, and the polishing time is 50 min.

[0038] The step (5) is specifically as follows: the microcrystalline glass is placed into the mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, is strengthened at the temperature of 450℃ for 410 min, and the strengthened microcrystalline glass is obtained; wherein, the mass ratio of the potassium nitrate and the sodium nitrate is 6:4, and the content of the lithium nitrate is 0.2 wt%.

[0039] In the step (6), the process parameters of the body polishing are as follows: the brush speed is 900 / min, the grinding powder concentration is 1.0 g / mL, the feeding speed is 200 mm / min for the short side, 220 mm / min for the long side, and 1000 mm / min for the four R corners, the polishing is performed by using the mixed pig hair and grinding leather, and the polishing time is 1.5 min.

[0040] In the step (7), the process parameters of the 2.5D surface polishing are as follows: the upper disc speed is 12 r / min, the lower disc speed is 20 r / min, the pressure is 250 kg, the grinding powder concentration is 1.0 g / mL, the upper polishing is performed by using the blanket, the lower polishing is performed by using the grinding leather, and the polishing time is 2-6 min.

[0041] The microcrystalline glass has a crystal phase content of 40 wt%, and the crystal phases are lithium disilicate and lithium feldspar, with an average particle size of 30 nm.

[0042] The thermal expansion ratio of the microcrystalline glass is 70*10. -7 / ℃, Young's modulus is 96.5 MPa, transmittance is 90%, haze is ≤0.16%, and Vickers hardness is 700.

[0043] Example 2

[0044] A processing method for microcrystalline glass includes the following steps:

[0045] (1) CNC machining: The glass is machined by CNC to engrave the shape and holes. The CNC finishing cutting amount is 0.04mm per cut.

[0046] (2) Sweep the glass: Overlap the glass and sweep the glass around the edges.

[0047] (3) Sweep the 2.5D surface: Place the swept glass sheet on the base, and then sweep the 2.5D surface of the glass for 12 minutes.

[0048] (4) Double-sided polishing: Polish the 2.5D side and the back of the glass; polishing time is 60 minutes;

[0049] (5) Strengthening: Chemical strengthening of glass;

[0050] (6) Polishing the glass body: Overlap the glass and polish the glass body around the edges;

[0051] (7) Polishing the 2.5D surface: Place the glass sheet after edge sweeping on the base, and then polish the 2.5D surface of the glass.

[0052] In step (1), the CNC machining process parameters are as follows: the spindle motor speed is 38000 r / min, roughing is performed twice, and then finishing is performed four times; roughing is performed using a grinding head with a surface coated with 500-mesh diamond abrasive, the straight edge speed is 800 mm / min, the angular speed is 300 mm / min, and the feed amount for both roughing operations is 0.17 mm; finishing is performed using a grinding head with a surface coated with 1000-mesh diamond abrasive, the straight edge speed is 300 mm / min, the angular speed is 300 mm / min, the feed amount for all four finishing operations is 0.04 mm, and the total machining time is 18 min.

[0053] In the step (2), the process parameters of the body polishing are as follows: the brush rotating speed is 1050 / min, the polishing powder concentration is 1.2 g / mL, the single side grinding amount is 0.02 mm, the feeding speed is 240 mm / min for the short side, 260 mm / min for the long side, and 1150 mm / min for the four R angles, the polishing is performed by using the mixed pig hair and leather strip, and the polishing time is 60 min.

[0054] In the step (3), the process parameters of the 2.5D surface polishing are as follows: the rotating speed is 40 r / min, the positive and negative are each 2 times, the pressure is 40 Kg, the current is 20-24 A, the polishing is performed by using the blanket, and the polishing time is 12 min.

[0055] In the step (4), the process parameters of the double side polishing are as follows: the upper disc rotating speed is 15 r / min, the lower disc rotating speed is 24 r / min, the pressure is 350 Kg, the polishing powder concentration is 1.1 g / mL, the upper and lower polishing are both performed by using the white leather with a thickness of 4 mm, and the polishing time is 60 min.

[0056] In the step (5), the microcrystalline glass is placed into a mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, and is strengthened at a temperature of 460℃ for 420 min to obtain the strengthened microcrystalline glass; wherein the mass ratio of the potassium nitrate and the sodium nitrate is 7:3, and the content of the lithium nitrate is 0.3wt%.

[0057] In the step (6), the process parameters of the body polishing are as follows: the brush rotating speed is 1050 / min, the polishing powder concentration is 1.2 g / mL, the feeding speed is 240 mm / min for the short side, 260 mm / min for the long side, and 1150 mm / min for the four R angles, the polishing is performed by using the mixed pig hair and leather strip, and the polishing time is 2 min.

[0058] In the step (7), the process parameters of the 2.5D surface polishing are as follows: the upper disc rotating speed is 15 r / min, the lower disc rotating speed is 24 r / min, the pressure is 350 Kg, the polishing powder concentration is 1.1 g / mL, the upper polishing is performed by using the blanket, and the lower polishing is performed by using the leather, and the polishing time is 6 min.

[0059] The crystalline phase content of the microcrystalline glass is 45wt%, and the average grain size of the crystalline phase is 50 nm.

[0060] The thermal expansion ratio of the microcrystalline glass is 72.2*10 -7 / ℃, the Young's modulus is 98.8 Mpa, the transmittance is 91.3%, the haze is ≤0.16%, and the Vickers hardness is 722.

[0061] Example 3

[0062] A processing technology of a microcrystalline glass, comprising the following steps:

[0063] (1) CNC machining: the glass is engraved with CNC machining profile and hole position, and the CNC finishing cutting amount is 0.05mm for single tool;

[0064] (2) Body scanning: the glass is overlapped, and the body around the glass is scanned;

[0065] (3) 2.5D surface scanning: the glass single piece after edge scanning is placed on the base, and then the 2.5D surface of the glass is scanned, and the scanning time is 14min;

[0066] (4) Double-sided polishing: the 2.5D surface and the back of the glass are polished; the polishing time is 70min;

[0067] (5) Strengthening: the glass is chemically strengthened;

[0068] (6) Polishing body: the glass is overlapped, and the body around the glass is polished;

[0069] (7) Polishing 2.5D surface: the glass single piece after edge scanning is placed on the base, and then the 2.5D surface of the glass is polished.

[0070] In step (1), the process parameters of CNC machining are: the spindle motor speed is 40000r / min, two roughing is performed first, and then four finishing is performed; roughing adopts a grinding head with a particle size of 600 mesh gold sand plated on the surface, the straight edge speed is 900mm / min, the corner speed is 400mm / min, and the feeding amount of two roughing is 0.19mm; finishing adopts a grinding head with a particle size of 1200 mesh gold sand plated on the surface, the straight edge speed is 400mm / min, the corner speed is 400mm / min, and the feeding amount of four finishing is 0.05mm, and the total processing time is 24min.

[0071] In step (2), the body scanning process parameters are: the brush speed is 1200 / min, the abrasive powder concentration is 1.4g / mL, the single side grinding amount is 0.03mm, the feeding speed is 280mm / min for short side, 300mm / min for long side, and 1200mm / min for four R corners, and the polishing is performed by using a mixture of pig hair and abrasive strip, and the polishing time is 70min.

[0072] In step (3), the 2.5D surface scanning process parameters are: the speed is 50r / min, the positive and negative are each 2 times, the pressure is 50Kg, the current is 24A, the polishing is performed by using a blanket, and the polishing time is 14min.

[0073] In the step (4), the process parameters of double-side polishing are as follows: the upper disc rotation speed is 18 r / min, the lower disc rotation speed is 28 r / min, the pressure is 400 kg, the polishing powder concentration is 1.2 g / mL, the white polishing leather with a thickness of 5 mm is used for upper and lower polishing, and the polishing time is 70 min.

[0074] In the step (5), the microcrystalline glass is placed into a mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, and is strengthened at a temperature of 470 ℃ for 430 min to obtain the strengthened microcrystalline glass; wherein the mass ratio of potassium nitrate to sodium nitrate is 8:2, and the content of lithium nitrate is 0.4 wt%.

[0075] In the step (6), the process parameters of body polishing are as follows: the brush rotation speed is 1200 / min, the polishing powder concentration is 1.4 g / mL, the feeding speed is 280 mm / min for the short side, 300 mm / min for the long side, 1200 mm / min for the four R corners, the pig hair and the polishing leather strip are mixed for polishing, and the polishing time is 2.5 min.

[0076] In the step (7), the process parameters of 2.5D face polishing are as follows: the upper disc rotation speed is 18 r / min, the lower disc rotation speed is 28 r / min, the pressure is 350 kg, the polishing powder concentration is 1.2 g / mL, the carpet is used for upper polishing, the polishing leather is used for lower polishing, and the polishing time is 6 min.

[0077] The crystal phase content of the microcrystalline glass is 50 wt%, the crystal phase is lithium disilicate and petalite, and the average particle size of the crystal phase is 70 nm.

[0078] The thermal expansion ratio of the microcrystalline glass is 75*10 -7 / ℃, the Young's modulus is 101.2 Mpa, the transmittance is 93%, the haze is ≤0.16%, and the Vickers hardness is 740.

[0079] Comparative Example 1

[0080] The difference between the embodiment and the above-mentioned embodiment 2 is that in the step (1), the feeding amount of the four-time fine polishing is 0.08 mm.

[0081] Comparative Example 2

[0082] The difference between the embodiment and the above-mentioned embodiment 2 is that in the step (3), the polishing time of 2.5D face polishing is 8 min.

[0083] Comparative Example 3

[0084] The difference between the embodiment and the above-mentioned embodiment 2 is that the polishing time of double-side polishing is 30 min.

[0085] Comparative Example 4

[0086] The embodiment is different from the embodiment 2 in that the step (6) polishing the body and the step (7) polishing the 2.5D surface are not performed.

[0087] Performance test: ten glass samples are taken for each embodiment and the comparative example respectively, and the test results are averaged.

[0088] The ball drop test conditions and steps are as follows: 1. a steel ball with a mass of 110g and a diameter of 30mm; the support width of the bearing fixture is 2±0.5mm, and the middle is avoided; 2. the steel ball is dropped from a height of 20cm, and the nine-grid window is measured three times at each point; 3. after the measurement, the height is increased by 5cm each time until the glass is broken.

[0089] The drop test conditions and steps are as follows: 1. the steel plate weighs 180g, the glass is attached to the steel plate, and the sandpaper is 80 mesh (the conventional mobile phone test sandpaper is 180 mesh); 2. the microcrystalline sample is dropped from a height of 40cm, and the height is increased by 10cm each time; 3. the glass is dropped stably, and the suction cup is in the center position.

[0090] The test parameters of the strengthened microcrystalline glass prepared in the embodiments 1-3 and the comparative examples 1-4 of the application are as follows:

[0091]

[0092]

[0093] As can be seen from the above table, the surface compressive stress CS_50 of the strengthened microcrystalline glass prepared by the processing technology of the application is 82.24-88.85MPa, the compressive stress depth DOL is 108.61-118.28μm; the average tensile stress CT_av is 47.79-49.52Mpa, the four-point bending test strength 4PB is 1193.02-1269.75MPa, the 110g ball drop test can reach 35-40cm, and the 180g weight 80 mesh sandpaper directional drop test can reach 100-110cm.

[0094] The above embodiments are the preferred implementation schemes of the application, and in addition thereto, the application can also be implemented in other ways, and any obvious replacement without departing from the concept of the application is within the protection scope of the application.

Claims

1. A process for machining glass-ceramics, characterized in that: It comprises the following steps: (1) CNC processing: the glass is processed in shape and hole position by CNC, and the CNC finishing cutting amount is 0.03-0.05mm for single tool; (2) Body scanning: the glass is overlapped, and the body around the glass is scanned; (3) 2.5D surface scanning: the glass single piece after edge scanning is placed on the base, and then the 2.5D surface of the glass is scanned, and the scanning time is 10-14min; (4) Double-sided polishing: the 2.5D surface and the back of the glass are polished; the polishing time is 50-70min; (5) Strengthening: the glass is chemically strengthened; (6) Polishing body: the glass is overlapped, and the body around the glass is polished; (7) Polishing 2.5D surface: the glass single piece after edge scanning is placed on the base, and then the 2.5D surface of the glass is polished; The step (5) is specifically: the microcrystalline glass is placed in a mixed molten salt containing potassium nitrate, sodium nitrate and lithium nitrate, and is strengthened at a temperature of 450-470℃ for 410-430min to obtain the strengthened microcrystalline glass; wherein the mass ratio of potassium nitrate and sodium nitrate is 6-8:2-4, and the content of lithium nitrate is 0.2wt%-0.4wt%. The crystal phase content of the microcrystalline glass is 40wt%-50wt%, the crystal phase is lithium disilicate and petalite, and the average particle size of the crystal phase is 30-70nm.

2. The process for processing the glass-ceramic according to claim 1, characterized in that: In the step (1), the process parameters of CNC processing are: the spindle motor speed is 36000-40000r / min, two roughing is performed first, and then four finishing is performed; The roughing adopts a grinding head with a particle size of 400-600 mesh gold sand plated on the surface, the straight edge speed is 700-900mm / min, the corner speed is 200-400mm / min, and the feeding amount of the two roughing is 0.15-0.19mm; the finishing adopts a grinding head with a particle size of 800-1200 mesh gold sand plated on the surface, the straight edge speed is 200-400mm / min, the corner speed is 200-400mm / min, the feeding amount of the four finishing is 0.03-0.05mm, and the total processing time is 16-24min.

3. The process for processing glass-ceramics according to claim 1, characterized in that: In the step (2), the process parameters of body scanning are: the brush speed is 900-1200 / min, the powder concentration is 1.0-1.4g / mL, the single edge grinding amount is 0.01-0.03mm, the feeding speed is 200-280mm / min for short edge, 220-300mm / min for long edge, and 1000-1200mm / min for four R corners, and pig hair and abrasive strip are used for polishing, and the polishing time is 50-70min.

4. The process for processing glass-ceramics according to claim 1, characterized in that: In the step (3), the process parameters of 2.5D surface scanning are: the speed is 30-50r / min, the positive and negative are each 2 times, the pressure is 30-50Kg, the current is 20-24A, the wool blanket is used for polishing, and the polishing time is 10-14min.

5. The process for processing glass-ceramics according to claim 1, characterized in that: In the step (4), the process parameters of double-sided polishing are as follows: the upper disc rotation speed is 12-18 r / min, the lower disc rotation speed is 20-28 r / min, the pressure is 300-400 kg, the polishing powder concentration is 1.0-1.2 g / mL, the white polishing leather with a thickness of 3-5 mm is used for upper and lower polishing, and the polishing time is 50-70 min.

6. The process for processing glass-ceramics according to claim 1, characterized in that: In the step (6), the process parameters of body polishing are as follows: the brush rotation speed is 900-1200 / min, the polishing powder concentration is 1.0-1.4 g / mL, the feeding speed is 200-280 mm / min for the short side, 220-300 mm / min for the long side, and 1000-1200 mm / min for the four R corners, the pig hair and polishing leather strip are mixed for polishing, and the polishing time is 1.5-2.5 min.

7. The process for processing glass-ceramics according to claim 1, characterized in that: In the step (7), the process parameters of 2.5D face polishing are as follows: the upper disc rotation speed is 12-18 r / min, the lower disc rotation speed is 20-28 r / min, the pressure is 250-350 kg, the polishing powder concentration is 1.0-1.2 g / mL, the carpet is used for upper polishing, the polishing leather is used for lower polishing, and the polishing time is 2-6 min.

8. The process for processing glass-ceramics according to claim 1, characterized in that: The thermal expansion ratio of the microcrystalline glass is 70*10 -7 -75*10 -7 / ℃, the Young's modulus is 96.5-101.2 MPa, the transmittance is 90%-93%, the haze is ≤0.16%, and the Vickers hardness is 700-740.

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