Synthetic block for synthesizing superhard composite sheet with diameter greater than 70mm and preparation method of synthetic block

Abstract

The invention relates to a synthesis block for synthesizing a superhard composite sheet with the diameter larger than 70 mm, the synthesis block is in a cuboid shape, the length and the width of the synthesis block are consistent and are 98-100 mm, the total height of two split blocks is 0.4-1 mm larger than the length or the width, and the inner diameter of the two split blocks is 79-83 mm; the synthesis block comprises a sealing layer, a cavity is formed in the sealing layer, a core column is arranged in the cavity and formed by stacking a plurality of green bodies, and the diameter of the core column is larger than 70 mm. During synthesis, the side length of a holding-up hammer of a cubic press is 84-88 mm, the angle of a small bevel edge is 41.5 DEG C, the length of the holding-up hammer is 18-20 mm, the diameter of the holding-up hammer is 240-260 mm, and the height of the holding-up hammer is 170-180 mm. By adopting the synthesis block disclosed by the invention, the problem of blasting during synthesis of the large-diameter superhard composite sheet can be effectively solved, and the superhard composite sheet with the diameter greater than 70mm can be safely synthesized.

Description

Technical Field

[0001] The invention relates to a synthetic block of a superhard composite sheet with a synthetic diameter greater than 70 mm and a preparation method thereof, belonging to the technical field of superhard materials. Background Art

[0002] As my country becomes the world's manufacturing center, advanced manufacturing technologies such as high-efficiency precision CNC machine tools, ultra-precision CNC machine tools, and CNC multifunctional machining centers are being used more and more widely in the fields of major basic equipment and pillar industries of the national economy. Superhard material cutting tools, superhard material grinding tools, and diamond rollers have become one of the essential basic equipment for realizing the above advanced manufacturing technologies, and market demand is also in a continuous growth process.

[0003] Moreover, with the advancement of technology, the demand for large-diameter superhard tool composites is also increasing. For example, there is a large demand for φ74mm superhard tool composites represented by Element Six, but the mainstream size of superhard tool composites produced by domestic companies is still 55-62mm, which cannot meet market demand.

[0004] The main problem is that in the process of synthesizing large-diameter superhard composite sheets using a six-sided top press, the blasting problem is quite serious, and it is impossible to prepare superhard composite sheets with a diameter greater than 70 mm. Summary of the invention

[0005] In view of the above problems, the present invention provides a synthetic block for synthesizing a superhard composite sheet with a diameter greater than 70 mm, and the specific scheme is as follows: The synthetic block is in the shape of a cuboid, and the length and width of the synthetic block are consistent, which are 98-100mm. The synthetic block includes a sealing layer, which is surrounded by a side sealing block and an end sealing block. The side sealing block is connected by two split blocks, and the total height of the two split blocks is 0.4-1mm larger than the length or width; a cavity is provided in the sealing layer, and the inner diameter of the cavity is 79-83mm; a core column is provided in the cavity, and the core column is composed of multiple stacked blanks, and the diameter of the core column is greater than 70mm.

[0006] In the prior art, the shape of the synthetic block is generally a cube, that is, the length, width and height are consistent. When used to synthesize superhard composite sheets with a diameter greater than 70 mm, after the size of the synthetic block is enlarged in proportion using a cube shape, it is easy to cause a blowout when it is loaded into a six-sided top press for synthesis. At the same time, if the size of the top hammer does not match the size of the pyrophyllite block, it is also easy to cause a blowout. Both of the above phenomena lead to synthesis failure.

[0007] The present invention redesigns the top hammer size and the synthetic block size, designs the height size to be slightly larger than the length and width sizes, and at the same time, the top hammer size and the synthetic block size are properly matched to form a safe sealing structure, which can effectively reduce the explosion phenomenon.

[0008] Furthermore, the sealing layer is composed of a side sealing block and an end sealing block. The side sealing block is formed by pressing a mixture of pyrophyllite and water glass and then baking at 200-300°C, so as to obtain good sealing performance. The end sealing block is formed by pressing a mixture of pyrophyllite and water glass and then baking at 300-1000°C, so as to obtain higher pressure transmission and a sealing effect.

[0009] The baking temperature of the pyrophyllite sealing block prepared with water glass as a binder has a significant effect on the pressure transmission performance of the sealing block. In the prior art, the baking temperature of the side and end sealing blocks is generally the same, that is, the pressure transmission performance of the side and end sealing blocks is consistent.

[0010] In the present invention, the height of the composite block is slightly greater than the length and width, and the side sealing block and the end sealing block are baked at different temperatures accordingly. The end sealing block adopts a higher baking temperature, and the pressure transmission performance is higher than that of the side sealing block, which can further solve the problem of explosion during synthesis.

[0011] Furthermore, a heat-insulating layer is arranged inside the sealing layer, and the heat-insulating layer is formed by pressing a mixture of dolomite and water glass and then baking it at 250-300°C.

[0012] Furthermore, a radial heating layer is provided at the end of the core column, and the radial heating layer is made of graphite, a composite of graphite and molybdenum sheets, or a composite of graphite and titanium sheets; an axial heating layer is provided at the side of the core column, and the axial heating layer is made of graphite, and the axial heating layer and the radial heating layer are connected. By adjusting the resistance of the radial and axial heating materials respectively, radial and axial power redistribution is achieved, spatial isothermal heating is established, and a uniform temperature field distribution is provided, which lays the foundation for the uniformity of the radial performance of the product.

[0013] Furthermore, a pressure transmission layer is provided at the end of the core column, and the pressure transmission layer is a composite of one or more of aluminum oxide, silicon nitride, silicon carbide, and aluminum nitride. Ceramic materials have high density, high temperature resistance, and high strength, and can obtain a higher pressure transmission coefficient, that is, a greater internal pressure, which provides a strong guarantee for the excellent performance of the product.

[0014] Furthermore, a heat-conducting layer is sandwiched between adjacent blanks of the core column, and the heat-conducting layer is a composite of one or more of a steel column, a titanium sheet, and a graphite sheet. This improvement can promote the uniformity of the temperature field of the synthetic cavity.

[0015] The present invention also claims a method for preparing a superhard composite sheet with a diameter greater than 70 mm using the above-mentioned synthetic block, wherein the method uses a six-sided top press for synthesis. The top hammer of the six-sided top press has a side length of 84-88 mm, a small bevel angle of 41.5°, a length of 18-20 mm, a top hammer diameter of 240-260 mm, and a height of 170-180 mm.

[0016] Furthermore, the length and width of the composite block are 100mm, the total height of the two split blocks is 100.6mm, and the inner diameter is 83mm; the side length of the top hammer is 88mm, the angle of the small hypotenuse is 41.5°, the length is 20mm, the top hammer diameter is 260mm, and the height is 180mm.

[0017] Furthermore, the length and width of the composite block are 99 mm, the total height of the two split blocks is 99.6 mm, the inner diameter is 80.5 mm, the side length of the top hammer is 87 mm, the angle of the small hypotenuse is 41.5°, the length is 19 mm, the top hammer diameter is 250 mm, and the height is 175 mm.

[0018] The synthesis block of the present invention can effectively solve the problem of blasting during the synthesis of large-diameter superhard composite sheets, and can safely synthesize superhard composite sheets with a diameter greater than 70 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the synthesis block structure of the present invention.

[0020] Figure 2 This is the superhard composite sheet prepared in Example 2. DETAILED DESCRIPTION

[0021] The scheme of the present invention is described in detail below with reference to specific examples.

[0022] Embodiment 1: like Figure 1The synthetic block structure shown in the figure, the side sealing block 8 is a split block, the two split blocks are combined, the length and width are 100mm, the total height of the two split blocks is 100.6mm, and the inner diameter is 83mm; the top hammer side length of the six-sided top press used in the synthesis is 88mm, the angle of the small bevel is 41.5°, the length is 20mm, the top hammer diameter is 260mm, and the height is 180mm. Pyrophyllite (weight ratio 90%) and water glass (weight ratio 10%) are mixed and pressed, and then baked at 300℃ to obtain a split block; the end sealing block 1 is a mixture of pyrophyllite (95%) and water glass (5%), pressed, and baked at 900℃. The middle conductive structure is a steel column with a doctoral hat structure, which is used to connect the current of the top hammer to the radial heating layer 3; the insulation layer 2 is a mixture of dolomite and water glass, which is pressed and baked at 300°C; the radial heating layer 3 is composed of graphite paper + molybdenum sheet, which generates a radial heat source; the axial heating layer 4 is graphite paper, which generates an axial heat source; the heat-conducting layer 6 is a molybdenum sheet, which quickly conducts the heat generated in the axial direction to the center to promote the uniformity of the temperature field. The heat-conducting layer 6 is sandwiched in the middle of the superhard material blank 5, and the multi-layer blank 5 and the heat-conducting layer 6 constitute the core column; the pressure-transfer layer 7 is silicon carbide ceramic, and the high strength and high density are conducive to the conduction of the pressure in the cavity, and improve the pressure-transfer efficiency of the cavity. This design can synthesize a composite sheet with a diameter of 75mm.

[0023] Example 2 The side sealing block 8 is a split block. The two split blocks together have a length and width of 99mm, a total height of 99.6mm, and an inner diameter of 80.5mm. The top hammer of the six-sided top press used in the synthesis has a side length of 87mm, a small bevel angle of 41.5°, a length of 19mm, a top hammer diameter of 250mm, and a height of 175mm. Pyrophyllite (weight ratio 90%) and water glass (weight ratio 10%) are mixed and then pressed, and then baked at 280°C to obtain a split block; the end sealing block 1 is obtained by mixing pyrophyllite (weight ratio 95%) and water glass (weight ratio 5%) and then pressing, and then baking at a high temperature of 600°C. The intermediate conductive structure is a large steel cap structure, which is used to connect the current of the top hammer to the radial heating layer 3; the thermal insulation layer 2 is formed by mixing dolomite and water glass and then pressing, and then baking at 280°C; the radial heating layer 3 is composed of graphite paper + titanium sheet to generate a radial heat source; the axial heating layer 4 is a graphite ring to generate an axial heat source; the heat-conducting layer 6 is graphite, which quickly conducts the heat generated in the axial direction to the center to promote the uniformity of the temperature field. The heat-conducting layer 6 is sandwiched in the middle of the superhard material blank 5, and the multi-layer blank 5 and the heat-conducting layer 6 constitute a core column; the pressure transfer layer 7 is aluminum nitride ceramic, and its high strength and high density are conducive to the conduction of pressure in the cavity and improve the pressure transfer efficiency of the cavity. This design can synthesize composite sheets with a diameter of 74 mm. Figure 2 shown.

[0024] Example 3 The side sealing block 8 is a split block. The two split blocks are combined, and the length and width are 98mm. The total height of the two split blocks is 99mm, and the inner diameter is 79mm. The top hammer of the six-sided top press used in the synthesis has a side length of 84mm, a small bevel angle of 41.5°, a length of 18mm, a top hammer diameter of 240mm, and a height of 172mm. The split block is obtained by mixing phyllite (90% by weight) and water glass (10% by weight) and pressing them, and then baking them at 280°C; the end sealing block 1 is obtained by mixing phyllite (95% by weight) and water glass (5% by weight) and pressing them, and then baking them at a high temperature of 1000°C. The intermediate conductive structure is a large steel cap structure, which is used to connect the current of the top hammer to the radial heating layer 3; the thermal insulation layer 2 is formed by mixing dolomite and water glass and pressing them, and then baking them at 250°C; the radial heating layer 3 is composed of graphite paper + molybdenum sheet + titanium sheet to generate a radial heat source; the axial heating layer 4 is a graphite ring to generate an axial heat source; the heat-conducting layer 6 is graphite + salt, which quickly conducts the heat generated in the axial direction to the center to promote the uniformity of the temperature field, and the heat-conducting layer 6 is sandwiched in the middle of the superhard material blank 5, and the multi-layer blank 5 and the heat-conducting layer 6 constitute a core column; the pressure transfer layer 7 is alumina ceramic, and its high strength and high density are conducive to the conduction of pressure in the cavity and improve the pressure transfer efficiency of the cavity. This design can synthesize composite sheets with a diameter of 74mm.

Claims

1. A synthetic block for synthesizing a superhard composite sheet with a diameter greater than 70 mm, characterized in that: The synthetic block is in the shape of a cuboid, and the length and width of the synthetic block are consistent, which are 98-100mm. The synthetic block includes a sealing layer, which is surrounded by a side sealing block and an end sealing block. The side sealing block is connected by two split blocks, and the total height of the two split blocks is 0.4-1mm larger than the length or width; a cavity is provided in the sealing layer, and the inner diameter of the cavity is 79-83mm; a core column is provided in the cavity, and the core column is composed of multiple stacked blanks, and the diameter of the core column is greater than 70mm.

2. The synthetic block of the superhard composite sheet with a synthetic diameter greater than 70 mm according to claim 1, characterized in that: The side sealing block is formed by pressing a mixture of pyrophyllite and water glass and then baking it at 200-300°C; the end sealing block is formed by pressing a mixture of pyrophyllite and water glass and then baking it at 300-1000°C.

3. The synthetic block of the superhard composite sheet with a synthetic diameter greater than 70 mm according to claim 1, characterized in that: An insulation layer is arranged inside the sealing layer. The insulation layer is formed by pressing a mixture of dolomite and water glass and then baking it at 250-300°C.

4. The synthetic block for synthesizing a superhard composite sheet with a diameter greater than 70 mm according to claim 1, characterized in that: A radial heating layer is provided at the end of the core column, and the radial heating layer is graphite, a composite of graphite and molybdenum sheets, or a composite of graphite and titanium sheets; an axial heating layer is provided at the side of the core column, and the axial heating layer is graphite, and the axial heating layer and the radial heating layer are connected.

5. The synthetic block of the superhard composite sheet with a synthetic diameter greater than 70 mm according to claim 1, characterized in that: The end of the core column is provided with a pressure transmission layer, which is one or a composite of two or more of an aluminum oxide sheet, a silicon nitride sheet, a silicon carbide sheet and an aluminum nitride sheet.

6. The synthetic block for synthesizing a superhard composite sheet with a diameter greater than 70 mm according to claim 1, characterized in that: A heat-conducting layer is sandwiched between adjacent blanks of the core column, and the heat-conducting layer is a composite of one or more of a steel column, a titanium sheet, and a graphite sheet.

7. A method for preparing a superhard composite sheet with a diameter greater than 70 mm, characterized in that: The synthesis block as described in any one of claims 1 to 6 is synthesized using a six-sided top press. The top hammer of the six-sided top press has a side length of 84-88 mm, a small bevel angle of 41.5°, a length of 18-20 mm, a top hammer diameter of 240-260 mm, and a height of 170-180 mm.

8. The synthetic block for synthesizing a superhard composite sheet with a synthetic diameter greater than 70 mm according to claim 7, characterized in that: The length and width of the composite block are 100mm, the total height of the two split blocks is 100.6mm, and the inner diameter is 83mm; the side length of the top hammer is 88mm, the angle of the small hypotenuse is 41.5°, the length is 20mm, the top hammer diameter is 260mm, and the height is 180mm.

9. The synthetic block for synthesizing a superhard composite sheet with a diameter greater than 70 mm according to claim 7, characterized in that: The length and width of the composite block are 99mm, the total height of the two split blocks is 99.6mm, the inner diameter is 80.5mm, the side length of the top hammer is 87mm, the angle of the small hypotenuse is 41.5°, the length is 19mm, the top hammer diameter is 250mm, and the height is 175mm.

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