Sapphire crystal growth furnace and growth process

Abstract

The invention relates to the technical field of crystal growth, and discloses a sapphire crystal growth furnace and a growth technology.The sapphire crystal growth furnace comprises a combustion furnace, the upper surface of the combustion furnace is fixedly connected with a furnace cover, the inner surface of the bottom end of the combustion furnace is rotatably connected with a main shaft, the top end of the main shaft is fixedly connected with a reciprocating lead screw, and the circumferential surface of the reciprocating lead screw is in threaded connection with a groove nut; according to the device, crystal raw materials fall onto the conical surface of the conical discharging plate and then flow to the periphery of the conical discharging plate under the influence of gravity, so that all positions of a combustion furnace can be rapidly filled with the crystal raw materials during discharging, the distribution uniformity of the crystal raw materials is improved, and the service life of the combustion furnace is prolonged. Further, the crystal raw materials are heated more uniformly, the growth efficiency and the growth quality of the crystals are promoted, centrifugal force is generated when the conical discharging plate rotates, the shaking amplitude of the crystal raw materials is promoted, and the distribution uniformity of the crystal raw materials is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of crystal growth, and in particular to a sapphire crystal growth furnace and a growth process. Background Art

[0002] Sapphire crystal is a corundum mineral, the main component of which is aluminum oxide. Its chemical formula is . Its crystal structure is a hexagonal lattice structure. It has a high hardness, second only to diamond, and has a bright glass luster. There are several methods for growing sapphire crystals, such as the pyrolysis method, the guided mold method, the heat exchange method, and the horizontal zone melting method. These methods and equipment all indirectly control the sapphire crystal growth interface temperature by inputting power, thereby achieving the control of sapphire crystal growth. In the prior art, the crystal raw material is heated unevenly during melting, and the melting efficiency is low, resulting in slow crystal growth.

[0003] The patent with announcement number CN219586231U discloses a sapphire crystal growth furnace. The crystal growth component of the patent includes a heating furnace placed above a supporting platform stand. A plurality of groups of heating tubes are evenly arranged on the inner wall of the furnace body of the heating furnace, and a crucible is placed between the plurality of groups of heating tubes inside the furnace body of the heating furnace. A heat exchanger is arranged at the bottom of the heating furnace just below the crucible. By arranging a plurality of groups of heating tubes that are independent of each other and evenly arranged in order inside the growth furnace, the plurality of heating tubes can be independently and gradiently heated from bottom to top, and then the growth furnace performs gradient heating from bottom to top on the sapphire crystal raw material inside the crucible, thereby improving the accuracy of the growth interface temperature of the sapphire crystal raw material, improving the growth efficiency, and reducing the incomplete growth of the sapphire crystal raw material caused by the large temperature difference. Although the patent solves the above problems, there is still the problem that the crystal raw material is unevenly heated when it is melted, resulting in slow crystal growth. Therefore, a sapphire crystal growth furnace and a growth process are proposed to solve the above problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a sapphire crystal growth furnace and a growth process in view of the deficiencies in the above-mentioned prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a sapphire crystal growth furnace, including a combustion furnace, a furnace cover is fixedly connected to the upper surface of the combustion furnace, a main shaft is rotatably connected to the inner surface of the bottom end of the combustion furnace, a reciprocating screw is fixedly connected to the top end of the main shaft, a groove nut is threadedly connected to the circumferential surface of the reciprocating screw, a conical blanking plate is rotatably connected to the inner surface of the groove nut, an annular limit plate is fixedly connected to the inner wall of the combustion furnace, a first fixed ring is fixedly connected to the circumferential surface of the main shaft, a transmission connecting plate is fixedly connected to the circumferential surface of the first fixed ring, a push rod is fixedly connected to the upper surface of the transmission connecting plate, a temperature gradient feeding device for intermittently adding zirconium oxide powder to increase the temperature in the combustion furnace in a step-by-step manner is arranged on the rear side of the combustion furnace, a melt filtering device for filtering and eliminating the melt generated in the crystal growth process to prevent the crystal from cracking is arranged inside the combustion furnace, and a through hole is opened on the surface of the conical blanking plate, The circumferential surface of the push rod is slidably connected to the inner surface of the conical blanking plate, the bottom end of the main shaft is fixedly connected to a motor, and the upper surface of the motor is fixedly connected to the lower surface of the combustion furnace. Open the furnace cover, pour the crystal raw material into the combustion furnace, close the furnace cover, start the motor, and the motor drives the main shaft to rotate, and the main shaft drives the reciprocating screw to rotate, and the reciprocating screw drives the groove nut to move reciprocatingly up and down, and the groove nut drives the conical blanking plate to move reciprocatingly up and down. When the conical blanking plate moves, it drives the crystal raw material that falls on its upper surface to shake, so that the crystal raw material falls from the through hole opened on the conical blanking plate into the combustion furnace, and after the crystal raw material falls on the conical surface of the conical blanking plate, it is affected by gravity and flows around the conical blanking plate. The rotation of the main shaft drives the first fixed ring to rotate, the first fixed ring drives the transmission connecting plate to rotate, and the transmission connecting plate drives the push rod to rotate, and the push rod pushes the conical blanking plate to rotate in the groove nut, and centrifugal force is generated when the conical blanking plate rotates.

[0006] Preferably, the temperature ladder feeding device includes a fixed material box, a feeding valve, a quantitative detector, a discharge box, and a blanking chute. The fixed material box is fixedly connected to the rear side of the combustion furnace, the feeding valve is fixedly connected to the left side of the fixed material box, the quantitative detector is fixedly connected to the inner wall of the fixed material box, the discharge box is fixedly connected to the lower surface of the fixed material box, and the blanking chute is opened at the top of the discharge box. The temperature ladder feeding device also includes a baffle, a resistance plate, an elastic telescopic rod, a connecting sleeve rod, a sliding rod, and a semicircular push block. The baffle is slidably connected to the inner wall of the discharge box, and the resistance plate is connected to the inner wall of the discharge box. The plate is fixedly connected to the lower surface of the baffle, the elastic telescopic rod is fixedly connected to the rear side of the resistance plate, the connecting sleeve rod is fixedly connected to the inner wall of the unloading box, the sliding rod is slidably connected to the inner surface of the connecting sleeve rod, the semicircular push block is fixedly connected to the front end of the slide rod, the front side of the unloading box and the rear side of the combustion furnace are fixedly connected, the rear end of the elastic telescopic rod is fixedly connected to the rear side of the inner wall of the unloading box, the rear end of the slide rod and the front side of the resistance plate are in contact with each other, the circumferential surface of the push rod and the arc surface of the semicircular push block are in contact with each other, and the crystal raw material is burned. During the calcination process, adding zirconium oxide powder into the combustion furnace can increase the melting temperature, improve the melt stability, improve the thermal stress and inhibit the foam, thereby promoting the crystal growth. The zirconium oxide powder is input into the fixed material box through the feed valve. When the quantitative detector detects that the zirconium oxide powder is sufficient, the feed valve is controlled to be closed. When the push rod rotates, it contacts the arc surface of the semicircular push block and pushes the semicircular push block to move backward through the guidance of the arc surface. The semicircular push block drives the slide bar to slide backward in the connecting sleeve rod, and the slide bar pushes the contact plate to move backward. The contact plate then drives the baffle to slide backward in the discharge box. When the push rod is away from the semicircular push block, the elastic reset action of the elastic telescopic rod drives the baffle to slide forward and reset and block the blanking chute. The baffle then pushes the slide bar and the semicircular push block forward through the contact plate. When the push rod continues to rotate, it can repeatedly contact and separate with the semicircular push block, so that the baffle slides back and forth, so that the zirconium oxide powder intermittently falls from the fixed material box through the blanking chute into the discharge box, and then falls into the combustion furnace.

[0007] Preferably, the molten material filtering device comprises a filter plate, a slag box, and a box cover. The filter plate is fixedly connected to the inner wall of the combustion furnace, the slag box is fixedly connected to the rear side of the combustion furnace, and the box cover is hinged on the inner wall of the slag box. The molten material filtering device also comprises a second fixed ring, a rotating scraper, an L-shaped transmission rod, a sliding connecting rod, and a U-shaped scraper rod. The second fixed ring is fixedly connected to the circumferential surface of the main shaft, the rotating scraper is fixedly connected to the circumferential surface of the second fixed ring, the L-shaped transmission rod is fixedly connected to the lower surface of the semicircular push block, the sliding connecting rod is fixedly connected to the rear end of the L-shaped transmission rod, the U-shaped scraper rod is fixedly connected to the lower surface of the sliding connecting rod, the top of the rotating scraper plate and the lower surface of the filter plate are in contact with each other, the sliding connecting rod is slidably connected to the inner wall of the slag box, the L-shaped transmission rod slides from the inner wall of the combustion furnace to pass through the circumferential surface of the combustion furnace, the outer side surface of the U-shaped scraper rod and the inner wall of the slag box are in contact with each other, and when the crystal grows, the combustion A large amount of molten material will be generated in the furnace, which will lead to problems such as destroying the stability of crystal growth, prolonging the crystal growth time, and cracking of the crystal. During the flow of the molten material in the combustion furnace, it can flow to the bottom of the combustion furnace through the filter plate, while the crystal is blocked by the filter plate above, so that the molten material and the crystal are separated, which improves the stability of the crystal during growth. When the crystal growth is completed, the furnace cover is opened to fish out the crystal. At this time, the box cover can be opened to discharge the molten material from the slag box. The rotation of the main shaft drives the second fixed ring to rotate, and the second fixed ring drives the rotating scraper. The rotating scraper rotates and scrapes off the molten material accumulated around the filter plate. The semicircular push block moves back and forth to drive the L-shaped transmission rod to move back and forth. The L-shaped transmission rod drives the sliding connecting rod to slide back and forth in the slag box. The sliding connecting rod drives the U-shaped scraper rod to move back and forth to scrape off the molten material adhering to the slag box.

[0008] A growth process of a sapphire crystal growth furnace comprises the following steps: S1: Clean the furnace and insulation layer with alcohol, dust-free cloth, copper wire brush, industrial vacuum cleaner, etc. S2: opening the furnace cover (2), placing the crystal raw material into the combustion furnace (1), and allowing the crystal raw material to fall onto the conical discharge plate (33); S3: The conical unloading plate (33) rotates to quickly disperse the crystal raw materials to various parts of the combustion furnace (1), and then the furnace is closed, vacuumed and leak tested; S4: Determine the material processing and temperature increase according to different thermal fields and raw materials; S5: After the raw materials are melted, the melt is kept constant at high temperature for 3 to 5 hours; S6: Fill the furnace with argon gas to maintain the pressure in the furnace at 0.1-100 Pa; S7: lowering the seed crystal, judging whether the melt temperature is suitable for seeding according to the liquid flow velocity, the thickness of the liquid flow line, the presence and size of floating islands, whether the end of the seed crystal is melted and the brightness of the end of the seed crystal, and the temperature change of the thermocouple in the furnace; S8: Lower the seed crystal to 50-80 mm below the liquid level, ensure that the end of the seed crystal is melted from a square to a circular arc surface, and the seed crystal is transparent without any black sediment attached; S9: Insert the transparent seed crystal 5 to 40 mm below the liquid surface, reset the weight, and keep it constant for 10 to 30 minutes. If the seed crystal slowly grows 3 to 6 mm thick at the solid-liquid interface, the temperature can be determined to be appropriate. S10: If the crystal grows rapidly within 1 to 5 minutes, increase the power by 200 to 500 watts according to the thermal field conditions, keep it constant for 2 to 3 hours, wash the crystal again, and repeat step S9; S11: If the seed crystal fails to grow within 30 minutes or melts, reduce the power by 300-500 watts, keep it constant for 2-3 hours, wash the crystal again, and repeat step S9; S12: When the growth rate is judged to be appropriate, the pulling speed needs to be set to 0.3-3 mm / h, accompanied by 5-15 min / time / 2 mm instantaneous pulling, until the crystal knot diameter reaches 50-70 mm, then the shoulder expansion growth is started; S13: The crystal growth is carried out according to the S12 process, with the shoulder expansion rate not exceeding 3% to 6% of the weight, and the pulling speed is 0.3 to 1 mm / h. After the weight reaches 30 kg, it is turned to equal diameter growth, with the equal diameter growth pulling speed of 0.3 to 0.7 mm / h, and the crystal growth speed does not exceed 2.0 kg / h; S14: Ending growth. When the weight displayed on the scale exceeds 300kg, the pulling speed of the seed crystal rod is increased from 0.3-0.7mm / h to 3-5mm / h until the crystal weight signal is maintained at about 300kg and tends to be stable. At this time, it can be judged that the crystal growth is finished and separated from the crucible. The crystal growth rate at this stage does not exceed 2.0kg / h. S15: Cooling down, slowly reducing the power, annealing the crystal, the total cooling time is 120h, after the cooling is completed, continue to fill the furnace with argon for 48 to 72 hours to fill the pressure in the furnace to atmospheric pressure, open the furnace and take out the crystal.

[0009] The present invention adopts the above technical solution to bring the following beneficial effects: 1. In the sapphire crystal growth furnace and growth process, after the crystal raw material falls onto the conical surface of the conical feeding plate, it flows around the conical feeding plate under the influence of gravity, so that the crystal raw material can be quickly filled into various positions of the combustion furnace when being fed, thereby improving the uniformity of the distribution of the crystal raw material, thereby making the crystal raw material heated more evenly, promoting the growth efficiency and growth quality of the crystal, and generating centrifugal force when the conical feeding plate rotates, promoting the shaking amplitude of the crystal raw material, and further improving the uniformity of the distribution of the crystal raw material.

[0010] 2. The sapphire crystal growth furnace and growth process, when the quantitative detector detects that the zirconium oxide powder is sufficient, the feed valve is controlled to be closed, so as to control the rising range of the temperature in the combustion furnace and improve the combustion stability. The zirconium oxide powder intermittently falls from the fixed material box into the discharge box through the drop chute, and then falls into the combustion furnace. The zirconium oxide powder is intermittently added into the combustion furnace, so that the combustion temperature of the combustion furnace rises in a step-by-step manner, which significantly improves the quality and growth efficiency of the sapphire crystal.

[0011] 3. In the sapphire crystal growth furnace and growth process, the melt flows to the bottom of the combustion furnace through the filter plate, so that the melt and the crystal are separated, which improves the stability of the crystal during growth. The rotating scraper rotates and scrapes the melt accumulated around the filter plate, which improves the filtration efficiency, promotes the separation speed of the melt and the crystal, and further improves the stability of the crystal during growth. The U-shaped scraper rod scrapes the melt adhering to the slag box, improves the melt cleaning efficiency, promotes the hygienic cleaning effect of the combustion furnace, ensures the sanitation of the crystal combustion environment, and improves the quality of crystal growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the three-dimensional overall structure of the present invention; Figure 2 It is a schematic diagram of the front side cross-sectional three-dimensional structure of the combustion furnace of the present invention; Figure 3 It is a schematic diagram of the front side cross-sectional three-dimensional structure of the tapered blanking plate of the present invention; Figure 4 For the present invention Figure 3 A is a schematic diagram of the enlarged structure of the middle part; Figure 5 It is a schematic diagram of the front side cross-sectional three-dimensional structure of the temperature gradient feeding device of the present invention; Figure 6 For the present invention Figure 5 A schematic diagram of the enlarged structure of B; Figure 7 It is a schematic diagram of the front side cross-sectional three-dimensional structure of the melt filtering device of the present invention.

[0013] In the figure: 1. combustion furnace; 2. furnace cover; 3. main shaft; 31. reciprocating screw; 32. groove nut; 33. conical discharge plate; 34. annular limit plate; 35. first fixed ring; 36. transmission connecting plate; 37. push rod; 4. temperature gradient feeding device; 41. fixed material box; 42. feeding valve; 43. quantitative detector; 44. discharge box; 45. drop chute; 46. baffle; 47. resistance plate; 48. elastic telescopic rod; 49. connecting sleeve rod; 410. slide rod; 411. semicircular push block; 5. melt filtering device; 51. filter plate; 52. slag discharge box; 53. box cover; 54. second fixed ring; 55. rotating scraper; 56. L-shaped transmission rod; 57. sliding connecting rod; 58. U-shaped scraper rod. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1-Figure 7 One embodiment of the present invention is: a sapphire crystal growth furnace, including a combustion furnace 1, a furnace cover 2 is fixedly connected to the upper surface of the combustion furnace 1, a main shaft 3 is rotatably connected to the inner surface of the bottom end of the combustion furnace 1, a reciprocating screw 31 is fixedly connected to the top of the main shaft 3, a groove nut 32 is threadedly connected to the circumferential surface of the reciprocating screw 31, a conical blanking plate 33 is rotatably connected to the inner surface of the groove nut 32, an annular limit plate 34 is fixedly connected to the inner wall of the combustion furnace 1, a first fixed ring 35 is fixedly connected to the circumferential surface of the main shaft 3, a transmission connecting plate 36 is fixedly connected to the circumferential surface of the first fixed ring 35, a push rod 37 is fixedly connected to the upper surface of the transmission connecting plate 36, and after the crystal raw material falls on the conical surface of the conical blanking plate 33, it flows around the conical blanking plate 33 under the influence of gravity, so that the crystal raw material can be quickly discharged. Filling it into various positions of the combustion furnace 1 improves the uniformity of the distribution of the crystal raw material, thereby making the crystal raw material heated more evenly, promoting the growth efficiency and growth quality of the crystal. The rear side of the combustion furnace 1 is provided with a temperature gradient feeding device 4 for intermittently adding zirconium oxide powder to increase the temperature in the combustion furnace 1 in a step-by-step manner. The interior of the combustion furnace 1 is provided with a melt filtering device 5 for filtering and eliminating the melt generated in the crystal growth process to prevent the crystal from cracking. A through hole is opened on the surface of the conical feeding plate 33, and the circumferential surface of the push rod 37 is slidably connected to the inner surface of the conical feeding plate 33. The bottom end of the main shaft 3 is fixedly connected to a motor, and the upper surface of the motor is fixedly connected to the lower surface of the combustion furnace 1. When the conical feeding plate 33 rotates, centrifugal force is generated, which promotes the shaking amplitude of the crystal raw material and further improves the uniformity of the distribution of the crystal raw material.

[0016] Working principle: open the furnace cover 2, pour the crystal raw material into the combustion furnace 1, close the furnace cover 2, start the motor, the motor drives the main shaft 3 to rotate, the main shaft 3 drives the reciprocating screw 31 to rotate, the reciprocating screw 31 drives the groove nut 32 to move up and down, the groove nut 32 drives the conical blanking plate 33 to move up and down, and the conical blanking plate 33 moves when it moves. The crystal raw material falling on its upper surface is shaken, so that the crystal raw material falls from the through hole opened on the conical blanking plate 33 into the combustion furnace 1, and after the crystal raw material falls on the conical surface of the conical blanking plate 33, it is affected by gravity to the surrounding areas of the conical blanking plate 33. The main shaft 3 rotates to drive the first fixed ring 35 to rotate, and the first fixed ring 35 drives the transmission connecting plate 36 to rotate, and the transmission connecting plate 36 drives the push rod 37 to rotate, and the push rod 37 drives the conical feeding plate 33 to rotate in the groove nut 32. When the conical feeding plate 33 rotates, centrifugal force is generated, which promotes the shaking amplitude of the crystal raw material and further improves the uniformity of the distribution of the crystal raw material.

[0017] See also Figure 1-Figure 7 On the basis of the above embodiment, in another embodiment of the present invention, the temperature gradient feeding device 4 includes a fixed material box 41, a feeding valve 42, a quantitative detector 43, a discharge box 44, and a blanking chute 45. The fixed material box 41 is fixedly connected to the rear side of the combustion furnace 1, the feeding valve 42 is fixedly connected to the left side of the fixed material box 41, the quantitative detector 43 is fixedly connected to the inner wall of the fixed material box 41, the discharge box 44 is fixedly connected to the lower surface of the fixed material box 41, and the blanking chute 45 is opened at the top of the discharge box 44. When the quantitative detector 43 detects that the zirconium oxide powder is sufficient, the feeding valve 42 is controlled to be closed, so as to control the rising range of the temperature in the combustion furnace 1 and improve the combustion stability. The temperature gradient feeding device 4 also includes a baffle 46, a resistance plate 47, an elastic telescopic rod 48, a connecting sleeve rod 49, a sliding rod 410, and a semicircular push block 411. The baffle 46 is slidably connected to the inner wall of the discharge box 44, and the resistance plate 4 7 is fixedly connected to the lower surface of the baffle 46, the elastic telescopic rod 48 is fixedly connected to the rear side of the abutment plate 47, the connecting sleeve rod 49 is fixedly connected to the inner wall of the discharge box 44, the slide rod 410 is slidably connected to the inner surface of the connecting sleeve rod 49, the semicircular push block 411 is fixedly connected to the front end of the slide rod 410, the front side of the discharge box 44 and the rear side of the combustion furnace 1 are fixedly connected, the rear end of the elastic telescopic rod 48 and the rear side of the inner wall of the discharge box 44 are fixedly connected, the rear end of the slide rod 410 and the front side of the abutment plate 47 are in contact with each other, the circumferential surface of the push rod 37 and the arc surface of the semicircular push block 411 are in contact with each other, the zirconium oxide powder intermittently falls from the fixed material box 41 into the discharge box 44 through the blanking groove 45, and then falls into the combustion furnace 1, the zirconium oxide powder is intermittently added into the combustion furnace 1, so that the combustion temperature of the combustion furnace 1 rises in a step-by-step manner, which significantly improves the quality and growth efficiency of the sapphire crystal.

[0018] Working principle: During the combustion of crystal raw materials, adding zirconium oxide powder into the combustion furnace 1 can increase the melting temperature, improve the melt stability, improve thermal stress and inhibit foaming, thereby promoting crystal growth. The zirconium oxide powder is input into the fixed material box 41 through the feed valve 42. When the quantitative detector 43 detects that the zirconium oxide powder is sufficient, the feed valve 42 is controlled to be closed, so as to control the rising range of the temperature in the combustion furnace 1 and improve the combustion stability. When the push rod 37 rotates, it contacts the arc surface of the semicircular push block 411 and pushes the semicircular push block 411 to move backward through the guidance of the arc surface. The semicircular push block 411 drives the slide rod 410 to slide backward in the connecting sleeve rod 49, and the slide rod 410 drives the contact plate 47 to move backward, and the contact plate 47 drives The baffle 46 slides backward in the discharge box 44. When the push rod 37 moves away from the semicircular push block 411, the elastic reset action of the elastic telescopic rod 48 drives the baffle 46 to slide forward and reset and block the discharge chute 45. The baffle 46 then pushes the slide rod 410 and the semicircular push block 411 forward through the contact plate 47. When the push rod 37 continues to rotate, it can repeatedly contact and separate from the semicircular push block 411, so that the baffle 46 slides back and forth, and then the zirconium oxide powder intermittently falls from the fixed material box 41 through the discharge chute 45 into the discharge box 44, and then falls into the combustion furnace 1. The zirconium oxide powder is intermittently added into the combustion furnace 1, so that the combustion temperature of the combustion furnace 1 increases in a step-by-step manner, which significantly improves the quality and growth efficiency of the sapphire crystal.

[0019] See also Figure 1-Figure 7On the basis of the above embodiment, in another embodiment of the present invention, the melt filtering device 5 includes a filter plate 51, a slag box 52, and a box cover 53. The filter plate 51 is fixedly connected to the inner wall of the combustion furnace 1, the slag box 52 is fixedly connected to the rear side of the combustion furnace 1, and the box cover 53 is hinged to the inner wall of the slag box 52. The melt flows to the bottom of the combustion furnace 1 through the filter plate 51, so that the melt and the crystal are separated, which improves the stability of the crystal during growth. The rotating scraper 55 rotates and scrapes the melt accumulated around the filter plate 51, which improves the filtering efficiency, promotes the separation speed of the melt and the crystal, and further improves the stability of the crystal during growth. The melt filtering device 5 also includes a second fixed ring 54, a rotating scraper 55, an L-shaped transmission rod 56, a sliding connecting rod 57, and a U-shaped scraper rod 58. The second fixed ring 54 is fixed It is connected to the circumferential surface of the main shaft 3, the rotating scraper 55 is fixedly connected to the circumferential surface of the second fixed ring 54, the L-shaped transmission rod 56 is fixedly connected to the lower surface of the semicircular push block 411, the sliding connecting rod 57 is fixedly connected to the rear end of the L-shaped transmission rod 56, and the U-shaped scraper rod 58 is fixedly connected to the lower surface of the sliding connecting rod 57. The top of the rotating scraper 55 and the lower surface of the filter plate 51 are in contact with each other, the sliding connecting rod 57 and the inner wall of the slag box 52 are slidably connected, the L-shaped transmission rod 56 slides from the inner wall of the combustion furnace 1 to pass through the circumferential surface of the combustion furnace 1, and the outer side surface of the U-shaped scraper rod 58 and the inner wall of the slag box 52 are in contact with each other. The U-shaped scraper rod 58 scrapes off the molten material adhering to the slag box 52, thereby improving the molten material cleaning efficiency, promoting the hygienic cleaning effect of the combustion furnace 1, ensuring the sanitation of the crystal combustion environment, and improving the quality of crystal growth.

[0020] Working principle: When the crystal grows, a large amount of melt will be generated in the combustion furnace 1, which will lead to problems such as destroying the stability of crystal growth, prolonging the crystal growth time, and cracking of the crystal. During the flow of the melt in the combustion furnace 1, it can flow to the bottom of the combustion furnace 1 through the filter plate 51, while the crystal is blocked at the top by the filter plate 51, so that the melt and the crystal are separated, which improves the stability of the crystal during growth. When the crystal growth is completed, the furnace cover 2 is opened to fish out the crystal. At this time, the box cover 53 can be opened to discharge the melt from the slag box 52. The rotation of the main shaft 3 drives the second fixed ring 54 to rotate, and the second fixed ring 54 drives the rotating scraper 55 to rotate. The scraper 55 rotates and scrapes off the melt accumulated around the filter plate 51, thereby improving the filtering efficiency, promoting the separation speed of the melt and the crystal, and further improving the stability of the crystal during growth. The semicircular push block 411 moves back and forth to drive the L-shaped transmission rod 56 to move back and forth. The L-shaped transmission rod 56 drives the sliding connecting rod 57 to slide back and forth in the slag box 52. The sliding connecting rod 57 drives the U-shaped scraper rod 58 to move back and forth to scrape off the melt adhering to the slag box 52, thereby improving the melt cleaning efficiency, promoting the hygienic cleaning effect of the combustion furnace 1, ensuring the sanitation of the crystal combustion environment, and improving the quality of crystal growth.

[0021] The present invention provides a sapphire crystal growth furnace and growth process. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A sapphire crystal growth furnace, comprising a combustion furnace (1), characterized in that: The upper surface of the combustion furnace (1) is fixedly connected to a furnace cover (2); the inner surface of the bottom end of the combustion furnace (1) is rotatably connected to a main shaft (3); the top end of the main shaft (3) is fixedly connected to a reciprocating screw (31); the circumferential surface of the reciprocating screw (31) is threadedly connected to a groove nut (32); the inner surface of the groove nut (32) is rotatably connected to a conical blanking plate (33); the inner wall of the combustion furnace (1) is fixedly connected to an annular limit plate (34); the circumferential surface of the main shaft (3) is fixedly connected to a first fixing ring (35); the circumferential surface of the first fixing ring (35) is fixedly connected to a transmission connecting plate (36); the upper surface of the transmission connecting plate (36) is fixedly connected to a push rod (37); The rear side of the combustion furnace (1) is provided with a temperature gradient feeding device (4) for intermittently adding zirconium oxide powder to increase the temperature in the combustion furnace (1) in a stepwise manner. The interior of the combustion furnace (1) is provided with a melt filtering device (5) for filtering and eliminating melt generated during crystal growth to prevent crystal cracking.

2. A sapphire crystal growth furnace according to claim 1, characterized in that: A through hole is provided on the surface of the conical blanking plate (33); the circumferential surface of the push rod (37) is slidably connected to the inner surface of the conical blanking plate (33); a motor is fixedly connected to the bottom end of the main shaft (3); and the upper surface of the motor is fixedly connected to the lower surface of the combustion furnace (1).

3. A sapphire crystal growth furnace according to claim 2, characterized in that: The temperature gradient feeding device (4) comprises a fixed material box (41), a feeding valve (42), a quantitative detector (43), a discharge box (44), and a blanking chute (45); the fixed material box (41) is fixedly connected to the rear side of the combustion furnace (1); the feeding valve (42) is fixedly connected to the left side of the fixed material box (41); the quantitative detector (43) is fixedly connected to the inner wall of the fixed material box (41); the discharge box (44) is fixedly connected to the lower surface of the fixed material box (41); and the blanking chute (45) is opened at the top of the discharge box (44).

4. A sapphire crystal growth furnace according to claim 3, characterized in that: The temperature gradient feeding device (4) also includes a baffle (46), a contact plate (47), an elastic telescopic rod (48), a connecting rod (49), a slide rod (410), and a semicircular push block (411). The baffle (46) is slidably connected to the inner wall of the material discharge box (44), the contact plate (47) is fixedly connected to the lower surface of the baffle (46), the elastic telescopic rod (48) is fixedly connected to the rear side of the contact plate (47), the connecting rod (49) is fixedly connected to the inner wall of the material discharge box (44), the slide rod (410) is slidably connected to the inner surface of the connecting rod (49), and the semicircular push block (411) is fixedly connected to the front end of the slide rod (410).

5. A sapphire crystal growth furnace according to claim 4, characterized in that: The front side of the material discharge box (44) is fixedly connected to the rear side of the combustion furnace (1), the rear end of the elastic telescopic rod (48) is fixedly connected to the rear side of the inner wall of the material discharge box (44), the rear end of the sliding rod (410) and the front side of the contact plate (47) are in contact with each other, and the circumferential surface of the push rod (37) and the arc surface of the semicircular push block (411) are in contact with each other.

6. A sapphire crystal growth furnace according to claim 5, characterized in that: The molten material filtering device (5) comprises a filter plate (51), a slag discharge box (52), and a box cover (53); the filter plate (51) is fixedly connected to the inner wall of the combustion furnace (1); the slag discharge box (52) is fixedly connected to the rear side of the combustion furnace (1); and the box cover (53) is hinged to the inner wall of the slag discharge box (52).

7. A sapphire crystal growth furnace according to claim 6, characterized in that: The melt filtering device (5) further comprises a second fixed ring (54), a rotating scraper (55), an L-shaped transmission rod (56), a sliding connecting rod (57), and a U-shaped scraper rod (58); the second fixed ring (54) is fixedly connected to the circumferential surface of the main shaft (3); the rotating scraper (55) is fixedly connected to the circumferential surface of the second fixed ring (54); the L-shaped transmission rod (56) is fixedly connected to the lower surface of the semicircular push block (411); the sliding connecting rod (57) is fixedly connected to the rear end of the L-shaped transmission rod (56); and the U-shaped scraper rod (58) is fixedly connected to the lower surface of the sliding connecting rod (57).

8. A sapphire crystal growth furnace according to claim 7, characterized in that: The top end of the rotating scraper (55) and the lower surface of the filter plate (51) are in contact with each other, the sliding connecting rod (57) and the inner wall of the slag discharge box (52) are slidably connected, the L-shaped transmission rod (56) slides from the inner wall of the combustion furnace (1) to the circumferential surface of the combustion furnace (1), and the outer side surface of the U-shaped scraper rod (58) and the inner wall of the slag discharge box (52) are in contact with each other.

9. A growth process of a sapphire crystal growth furnace, using the sapphire crystal growth furnace of claim 8, characterized in that: The following steps are involved: S1: Clean the furnace and insulation layer with alcohol, dust-free cloth, copper wire brush, industrial vacuum cleaner, etc. S2: opening the furnace cover (2), placing the crystal raw material into the combustion furnace (1), and allowing the crystal raw material to fall onto the conical discharge plate (33); S3: The conical unloading plate (33) rotates to quickly disperse the crystal raw materials to various parts of the combustion furnace (1), and then the furnace is closed, vacuumed and leak tested; S4: Determine the material processing and temperature increase according to different thermal fields and raw materials; S5: After the raw materials are melted, the melt is kept constant at high temperature for 3 to 5 hours; S6: Fill the furnace with argon gas to maintain the pressure in the furnace at 0.1-100 Pa; S7: lowering the seed crystal, judging whether the melt temperature is suitable for seeding according to the liquid flow velocity, the thickness of the liquid flow line, the presence and size of floating islands, whether the end of the seed crystal is melted and the brightness of the end of the seed crystal, and the temperature change of the thermocouple in the furnace; S8: Lower the seed crystal to 50-80 mm below the liquid level, ensure that the end of the seed crystal is melted from a square to a circular arc surface, and the seed crystal is transparent without any black sediment attached; S9: Insert the transparent seed crystal 5 to 40 mm below the liquid surface, reset the weight, and keep it constant for 10 to 30 minutes. If the seed crystal slowly grows 3 to 6 mm thick at the solid-liquid interface, the temperature can be determined to be appropriate. S10: If the crystal grows rapidly within 1 to 5 minutes, increase the power by 200 to 500 watts according to the thermal field conditions, keep it constant for 2 to 3 hours, wash the crystal again, and repeat step S9; S11: If the seed crystal fails to grow within 30 minutes or melts, reduce the power by 300-500 watts, keep it constant for 2-3 hours, wash the crystal again, and repeat step S9; S12: When the growth rate is judged to be appropriate, the pulling speed needs to be set to 0.3-3 mm / h, accompanied by 5-15 min / time / 2 mm instantaneous pulling, until the crystal knot diameter reaches 50-70 mm, then the shoulder expansion growth is started; S13: The crystal growth is carried out according to the S12 process, with the shoulder expansion rate not exceeding 3% to 6% of the weight, and the pulling speed is 0.3 to 1 mm / h. After the weight reaches 30 kg, it is turned to equal diameter growth, with the equal diameter growth pulling speed of 0.3 to 0.7 mm / h, and the crystal growth speed does not exceed 2.0 kg / h; S14: Ending growth. When the weight displayed on the scale exceeds 300kg, the pulling speed of the seed crystal rod is increased from 0.3-0.7mm / h to 3-5mm / h until the crystal weight signal is maintained at about 300kg and tends to be stable. At this time, it can be judged that the crystal growth is finished and separated from the crucible. The crystal growth rate at this stage does not exceed 2.0kg / h. S15: Cooling down, slowly reducing the power, annealing the crystal, the total cooling time is 120h, after the cooling is completed, continue to fill the furnace with argon for 48 to 72 hours to fill the pressure in the furnace to atmospheric pressure, open the furnace and take out the crystal.

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