JP4873626B2 - Twin roll type vertical casting apparatus and composite material sheet manufacturing method - Google Patents

Description

  The present invention relates to a twin roll type vertical casting apparatus and a method for producing a sheet of a composite material containing metal and ceramic particles using the apparatus.

  Many proposals in the past have been filed regarding the twin roll casting method in which a molten metal is passed through a gap between a pair of opposed rotating rolls to obtain a sheet directly.

  The sheet manufacturing apparatus of Patent Document 1 has a structure in which the sheet is pulled out from the side, but because the cooling rate of the upper roll is slower than the cooling rate of the lower roll due to the gravity applied to the sheet, the surface quality differs between the front and back surfaces, and the plate thickness However, there was a problem that it was not stable. In addition, since the cooling rate of the roll is slow, it is difficult to increase the peripheral speed of the roll and the productivity is low.

  On the other hand, as in Patent Document 2, a structure in which a molten metal is supplied between a pair of cooling rolls and a sheet is drawn downward from between the pair of cooling rolls is also known. However, the manufacturing apparatus of Patent Document 2 directly affects the contact area (solidification distance) between the molten metal and the cooling roll because the fluctuation of the amount of molten metal supplied between the pair of cooling rolls, that is, the fluctuation of the molten liquid level directly affects the contact area (solidification distance). The molten metal surface must be constantly and delicately controlled, and if the control is a little out of order, the sheet appearance quality and the sheet thickness fluctuate.

  According to Patent Documents 1 and 2, as in Non-Patent Document 1, since a sheet is obtained by a technique such as rolling by applying a large load in units of tons to the cooling roll when passing through the cooling roll, Since the mechanical strength is required, the thickness of the cooling roll is increased and the cooling efficiency is lowered. That is, in the manufacturing apparatus of Patent Document 2, the contact area between the molten metal and the cooling roll varies depending on the amount of the molten metal, and it is difficult to control the sheet thickness obtained by roll casting and the solidified structure of the sheet uniformly. There is. In Patent Document 2, there is a method of reducing the peripheral speed of the roll in order to control the sheet thickness and the like constant regardless of the fluctuation of the molten metal amount, but this is not a fundamental solution, but rather the cooling efficiency is lowered. A new problem will occur.

  Furthermore, the manufacturing apparatus of Patent Document 2 has another problem that oxides and the like that are impurities for the sheet are easily generated and mixed because the interface between the molten metal and the roll is exposed to the atmosphere.

  In addition, because the cooling efficiency is poor, there is a possibility that unsolidified molten metal may adhere to the cooling roll, so that a release agent such as graphite powder is applied to the boundary between the molten metal and the roll in order to prevent the adhesion. Become. In either case, the cooling capacity of the cooling roll is reduced, and the peripheral speed of the cooling roll must be further reduced.

  On the other hand, since a composite material containing metal and ceramic particles has poor malleability and is hard, it is difficult to produce a sheet by rolling from a slab.

  Patent Document 3 describes a manufacturing method in which a mixed powder of a metal and an inorganic compound is supplied between heating rolls to form a composite material sheet. However, depending on how the mixed powder is adjusted, sufficient homogeneity is obtained. There is a risk of not. Moreover, the manufacturing method of the cited document 3 is completely different from the manufacturing method which manufactures a sheet | seat, cooling a molten metal with a cooling roll.

  Patent Document 4 proposes a method of forming an aluminum matrix composite material into an ingot and then rolling it into a sheet. With this method, the homogeneity is improved, but there is a problem that the production becomes complicated by the ingot-making process, leading to an increase in production cost. Therefore, neither of Patent Documents 3 and 4 proposes a manufacturing method for directly manufacturing a sheet from a molten composite material.

Patent Document 5 includes a twin belt method, a belt wheel method, a twin roll casting method, and a horizontal casting method as a method for forming a composite material containing metal and ceramic particles. It is only listed, and does not describe the specific contents of each method.
JP-A-8-10909 JP-A-6-154958 JP 2000-313904 A JP-A-10-183270 JP 2003-234445 A “Mechanical properties and microstructure of twin roll cast Al-7Si / SiCp MMCs” Materials Science and Technology Vol.11 p741

  The present invention improves the above-mentioned drawbacks of the prior art, and a twin roll type vertical casting apparatus and a composite material sheet manufacturing method for collecting a sheet having a stable thickness and quality at a high speed regardless of the state of the molten metal surface Is to provide. It is also proposed to streamline the apparatus by applying it to the pre-rolling process for metal matrix composites.

  The present invention achieves easy collection of a sheet having a stable thickness and quality at a high speed by facilitating the control of the melt surface.

In order to achieve the above object, the invention according to claim 1 is a twin-roll type vertical casting apparatus for producing a material excluding steel and Ni-based alloy into a sheet, and is disposed to face each other at a predetermined interval . the thickness of the portion in contact with the solvent water has less and mild steel of a pair of water-cooled rotary roll 10 mm, and a weir disposed to receive said melt of said material in a molten state on said pair of water-cooled rotating rolls The weirs are disposed in a pair of plate-like main weirs parallel to the rotation axis of the pair of water-cooled rotary rolls, and disposed at a right angle to the rotation axis of the pair of water-cooled rotary rolls, and at both ends of the pair of main weirs A pair of horizontal weirs connected to the surface, the lower ends of the one pair of main weirs contact the surface of one water-cooled rotary roll of the pair of water-cooled rotary rolls or form a gap of 2 mm or less, The lower end of the other main weir of the pair of Contact the surface of the other water-cooled rotary roll of the cold-rotating roll or form a gap of 2 mm or less, and the side surfaces of the pair of horizontal weirs contact the end surface of the water-cooled rotary roll or form a gap of 2 mm or less, The main weir and the pair of horizontal weirs are extended above the pair of water-cooled rotating rolls.

  As in the first aspect of the invention, by providing the weir on the water-cooled rotary roll, the liquid level of the molten metal may be controlled at the upper position of the water-cooled rotary roll, that is, the control of the melt liquid level becomes easy. Even if the peripheral speed of the water-cooled rotating roll is increased, the solidification speed can be controlled to be constant. Thereby, the sheet | seat with stable thickness and quality can be extract | collected at high speed, without being influenced by the state of a molten metal surface.

The invention described in claim 2 is characterized in that, in claim 1, the material is an aluminum silicon alloy or a composite material in which an aluminum silicon alloy and silicon carbide powder are mixed.
The invention according to claim 3 is the invention according to claim 1 or 2 , wherein the water-cooled rotating roll has a peripheral speed of 10 m / min or more, and the material of the water-cooled rotating roll has a thermal conductivity of 15 W / m · K or more. It is characterized by being.

According to claim 3 , when the water-cooled rotary roll is rotated at a high speed at a peripheral speed of 10 m / min or more in order to collect the sheet at a high speed, the thermal conductivity of the material of the water-cooled rotary roll is 15 W / m · If it is less than K, the molten metal is sent from the lower side of the water-cooled rotary roll in an unsolidified state, which is not preferable for sheet production. Therefore, by adopting a material having a thermal conductivity of 15 W / m · K or more as the material of the water-cooled rotary roll, it is possible to collect a sheet that has been sufficiently solidified at a high speed. In addition, as a material having a thermal conductivity of 15 W / m · K or more, mild steel, copper (400 W / m · K), or the like is preferable. Further, in order to increase the solidification rate, it is more preferable to increase the conductivity of the material and reduce the thickness of the roll to increase the cooling capacity of the roll. For example, in the case of a water-cooled rotating roll made of mild steel, it is preferable that the thickness of the portion in contact with the molten metal is 10 mm or less because sufficient cooling capacity is obtained and the solidification rate is increased.

The invention according to claim 4 is the structure according to claim 3 , wherein the contact between the weir and the water-cooled rotary roll and the vicinity of the gap portion are formed by affixing a silica fiber cloth and blowing boron nitride or graphite spray. characterized in that that.

According to the fourth aspect of the present invention , the contact between the weir and the water-cooled rotary roll and the vicinity of the gap portion are made of a material having low wettability, for example, a silica fiber cloth is attached to the vicinity of the tip of the weir, and boron nitride or graphite spray is further sprayed. By treating the molten metal so that the tip of the weir is difficult to wet, it is possible to prevent the molten metal from seeping out between the water-cooled rotating roll and the weir.

The invention according to claim 5 is characterized in that, in claim 3 , a heat insulating material is arranged in the weir.

According to the fifth aspect , by disposing a heat insulating material on the inner surface of the weir, it is possible to prevent the molten metal temperature from being lowered and to prevent deformation due to the temperature rise and expansion of the weir. By preventing the deformation of the weir, there is an advantage that it is possible to prevent the occurrence of a weir gap with respect to the water-cooled rotating roll. Further, by arranging the heat insulating material on the inner surface of the weir, interference with the water-cooled rotating roll of the heat insulating material can be prevented, but the heat insulating material may be arranged on the outer surface of the weir.

The invention according to claim 6, in using the twin-roll type vertical casting apparatus according to any one of claims 1 to 5 surrounded by the pair of lateral weirs and the pair of main weir space, before The molten metal is injected, and a composite material sheet is collected directly and continuously from between the pair of water-cooled rotary rolls.

Since the composite material sheet manufactured in claim 6 has a high heat dissipation property, it is used, for example, as a substrate of an electronic component that is built in a computer and generates high heat. In addition, the method of manufacturing the composite material sheet of the present invention is fundamentally different from the rolling method of manufacturing the sheet by crushing the particles of the material, and is a method of manufacturing the sheet by pressing with a low load without crushing the particles of the material. There is obtained a sheet having a structure similar to casting.

According to the seventh aspect of the present invention, in the sixth aspect , the molten metal temperature in the weir is set to a temperature that is 20 ° C. to 30 ° C. higher than the liquidus temperature of the material .

According to claim 7, when the temperature exceeds 30 ° C. from the liquidus temperature at which the metal changes from solid to liquid, there is a possibility that the molten metal cannot be solidified reliably by the water-cooled rotating roll, and 20 ° C. or more from the liquidus temperature. If it is low, the molten metal may solidify before it is supplied to the weir. For this reason, it is preferable to set the molten metal temperature in the weir to a temperature that is 20 ° C. lower than the metal liquidus temperature and 30 ° C. higher. This setting is particularly effective when the peripheral speed of the water-cooled rotary roll is 10 m / min or more and the thermal conductivity is 15 W / m · K or more.

The invention described in claim 8 is characterized in that, in claim 6 , the collected composite material sheet is further cold-rolled.

According to claim 8 , for example, when it is desired to obtain a sheet having a thickness of 3 mm or less, it can be obtained by cold rolling a composite material sheet collected by a water-cooled rotary roll.

The invention according to claim 9 is the invention according to claim 8 , wherein, as the cold rolling condition, a value obtained by subtracting a sheet thickness after rolling from a sheet thickness before rolling is divided by a sheet thickness before rolling. The rolling reduction, which is a value obtained by multiplying by 100, is 3 to 10% per pass.

According to the ninth aspect , if the rolling reduction per cold rolling condition is less than 3%, the sheet thickness is low and the number of passes increases, so that the sheet productivity is poor and the rolling reduction is 10%. If it exceeds 50%, the sheet may be cracked. Therefore, it is preferable that the cold rolling conditions are set at a reduction rate of 3 to 10% per pass.

A tenth aspect of the present invention is characterized in that in the eighth or ninth aspect , hot rolling is performed before the cold rolling.

According to the tenth aspect , the sheet cast and manufactured by the water-cooled rotary roll is hot-rolled before being cold-rolled, thereby taking a variation (unevenness) in the thickness of the sheet cast and manufactured by the water-cooled rotary roll. be able to.

The invention according to claim 11 is the invention according to claim 10 , wherein the preheating temperature of the hot rolling is 65 to 85% of the liquidus temperature of the metal, and the rolling reduction per pass is 10 to 20%. It is characterized by being.

According to the eleventh aspect, when the preheating temperature of the hot rolling is less than 65% of the liquidus temperature of the metal, it is difficult to take a variation in the thickness of the sheet because the sheet at the time of hot rolling is too hard. If the liquidus temperature exceeds 85%, the sheet becomes too soft, and it is also difficult to take variations in the sheet thickness. Therefore, it is preferable that the preheating temperature of hot rolling is 65 to 85% (preferably 75 to 80%) of the liquidus temperature of the metal.

  In addition, if the rolling reduction per pass of hot rolling is less than 10%, it is difficult to reliably remove the variation in the thickness of the sheet cast and manufactured by the water-cooled rotary roll, and the rolling reduction per pass is low. If it exceeds 20%, the sheet may be cracked. Therefore, it is preferable that the hot rolling condition is set to a reduction rate of 10 to 20% per pass.

  According to the twin roll type vertical casting apparatus and the composite material sheet manufacturing method according to the present invention, a sheet having a stable thickness and quality can be collected at a high speed without being affected by the state of the molten metal surface.

  Hereinafter, preferred embodiments of a twin roll type vertical casting apparatus and a composite material sheet manufacturing method according to the present invention will be described with reference to the accompanying drawings.

  1 and 2 show a configuration example of a typical twin roll type vertical casting apparatus 10 of the present invention. Since the molten metal 16 flows down from the top while being cooled by a pair of water-cooled rotary rolls 12 and 14 of the same size having the same diameter, peripheral speed, and cooling water amount, the surface state of the obtained solidified sheet 18 is aligned on both sides. Warpage is prevented and the plate thickness is stabilized.

  A pair of main weirs 22 and 24 constituting the weir 20, which is a main matter of the twin roll type vertical casting apparatus 10, are arranged in parallel with the rotating shafts 12A and 14A of the water-cooled rotating rolls 12 and 14, and the interval is fixed. The lower edge of the main weir 22 is in contact with the peripheral surface of the water-cooled rotary roll 12 or a gap of 2 mm or less is formed, and the lower edge of the main weir 24 is in contact with the peripheral surface of the water-cooled rotary roll 14 or a gap of 2 mm or less. Is formed. In the present invention, the contact is more preferable than the gap of 2 mm or less because there is no risk of molten metal leakage and stable production is easy. In the present invention, when a gap of 2 mm or less is formed without contacting the roll and the weir, the gap is more preferably 1.5 mm or less, and further preferably, the gap is 1.0 mm or less. The main weirs 22 and 24 extend above the water-cooled rotary rolls 12 and 14. As a result, even if the molten material 16 that is a molten material is injected from the container 26 between the water-cooled rotary rolls 12 and 14 and the liquid level in the main weirs 22 and 24 rises from B → C → D, the molten metal 16 and the water-cooled rotation are performed. The contact area (solidification distance) of the rolls 12 and 14 is kept constant by the arc AB of the water-cooled rotary rolls 12 and 14. For this reason, the cooling rate of the molten metal 16 is stable until the liquid level falls below B, and thus the quality of the obtained sheet 18 is also stabilized. Moreover, since the height of the liquid surface of the molten metal 16 is higher than that in the vertical twin roll casting apparatus having no main dam as in Patent Document 2, the pressure of the molten metal 16 applied to the position opposed to the water-cooled rotary rolls 12 and 14. Is increased, the adhesion between the molten metal 16 and the water-cooled rotary rolls 12 and 14 is improved, and the cooling efficiency of the molten metal 16 is improved. Furthermore, since the main weirs 22 and 24 and the water-cooled rotary rolls 12 and 14 are in contact with each other or a gap of 2 mm or less is formed, molten metal leakage between the molten metal 16 and the water-cooled rotary rolls 12 and 14 is eliminated. For this reason, it can prevent that the oxide of material mixes in the sheet | seat 18 except a terminal part. This is an advantage not found in the vertical twin roll casting apparatus of Patent Document 2. In addition, as compared with Patent Document 2, the liquid level of the molten metal 16 may be controlled to a point B or higher, so that the liquid level can be easily controlled.

  When the molten metal 16 is rapidly cooled by the water-cooled rotary rolls 12 and 14 which are another requirement of the twin-roll type vertical casting apparatus 10 according to the embodiment and have a thin wall and high thermal conductivity, that is, a high cooling capacity, solidified crystal grains are formed. Refined. It also has the effect of spheroidizing alloy components that crystallize as primary crystals. In particular, in an aluminum alloy containing silicon, the crystallized silicon is not needle-like and the dispersion is uniform, and thus exhibits good malleability that is not found in a slab rolled product in the next rolling process.

  There has been no report of an aluminum / silicon alloy having a silicon content exceeding 7% formed into a sheet by the roll casting method, and low temperature / high speed casting and rapid cooling in the twin roll type vertical casting apparatus 10 of the embodiment. It becomes possible for the first time by the combination.

  The effect of the manufacturing work surface is that solidification is completed in a very short time by rapid cooling, so that the problem that the sheet material adheres to the water-cooled rotary rolls 12 and 14 does not occur. Need not be applied. This creates a virtuous cycle that further contributes to an improvement in the molten metal cooling rate.

  As an effect of the equipment, since the thickness of the sheet 18 is stably determined by rapid solidification without applying a large compressive force to the gap between the water-cooled rotary rolls 12 and 14, the compressive force to the water-cooled rotary rolls 12 and 14 is Less than about 1/10 of the conventional vertical twin roll casting machine is sufficient, and it is not necessary to use a highly rigid water-cooled rotating roll. Therefore, there is an advantage that the structure of the entire twin roll type vertical casting apparatus 10 can be simplified and the apparatus cost can be reduced.

  By the way, when the contact between the main weirs 22 and 24 and the water-cooled rotary rolls 12 and 14 and the vicinity of the gaps are made of the material 28 having low wettability with respect to the molten metal 16 as shown in FIG. It is possible to prevent oozing out of the boundary between 22, 24 and the water-cooled rotary rolls 12, 14 or out of the boundary, which is effective in stabilizing the position of the contact surface between the molten metal 16 and the water-cooled rotary rolls 12, 14. In addition, as shown in FIG. 4, by disposing the heat insulating material 30 inside the main weirs 22 and 24, the molten metal 16 is partially formed on the inner surfaces of the main weirs 22 and 24 above the position opposed to the water-cooled rotary rolls 12 and 14. 5 has an effect of preventing the phenomenon shown in FIG. 5 that the gap between the water-cooled rotary rolls 12 and 14 is clogged by the solidified molten metal blob generated by solidification. In FIG. 5, the code | symbol 32 is the molten metal lump solidified.

  If the composite sheet 18 made of metal and ceramic particles is manufactured by the twin roll type vertical casting apparatus 10 of the embodiment, there is an advantage that cannot be obtained by other manufacturing methods.

  The first advantage is that the pressure of the water-cooled rotary rolls 12 and 14 can be set low due to high heat conduction, thin wall (that is, high cooling ability), and high-speed rotation. Segregation that is pushed up is less likely to occur. The second advantage is that since the solidified crystal grains are fine, the distribution of the ceramic particles existing along the crystal grain boundaries is made uniform. The third advantage is that the alloy component to be crystallized is fine and spherical as described above, which contributes to the uniform distribution of ceramic particles. With these effects, the homogeneity of the sheet 18 obtained by the twin roll type vertical casting apparatus 10 is improved and the cold rolling process can be applied, thereby reducing the manufacturing cost.

  As the structure of the water-cooled rotary rolls 12 and 14 of the embodiment, two cylinders having different diameters are concentrically fixed to a hub fixed to the rotary shafts 12A and 14B, and then a double cylinder structure is formed. The cooling water supply port and the discharge port can be provided at both ends of the space formed by the watertight treatment. This structure has less variation in the cooling capacity of the roll surface compared to the method of fixing the cooling pipe to the inner surfaces of the water-cooled rotary rolls 12 and 14, and contributes to uniform quality of the sheet 18 to be manufactured.

  Moreover, although the space | interval of the water-cooling rotary rolls 12 and 14 is fixed before pouring according to the target thickness of the sheet | seat 18, it can counter the pushing force by the material which passes the clearance gap between the water-cooling rotary rolls 12 and 14. In addition, it is necessary to apply pressure to one of the water-cooled rotary rolls 12 and 14 as shown in FIG.

  In the twin roll type vertical casting apparatus 10 of the embodiment, as shown in FIG. 1, a set of mechanisms of the water-cooled rotary roll 12 on the opposite side to the pouring is arranged on a rail 34 disposed in a direction orthogonal to the roll rotary shaft 12A. It is devised not to cause the thickness deviation in the width direction of the sheet 18 by preventing the water-cooled rotary rolls 12 and 14 from being pushed obliquely by placing the table 36 on the table 36 and urging the table 36 with a disc spring 38. Yes. In the present invention, the biasing means is not limited to the disc spring 38.

  For example, a heat insulating material 30 such as kao wool is adhered to the inner surfaces of the main weirs 22 and 24 with a heat-resistant adhesive to prevent a decrease in hot water temperature and to prevent deformation of the main weirs 22 and 24 due to temperature rise and expansion. . A silica fiber cloth is pasted in the vicinity of the front end portions of the main weirs 22 and 24, and further, boron nitride or graphite spray is sprayed to treat the front ends of the main weirs 22 and 24 so as not to get wet. That is, the material 28 with low wettability is disposed in the vicinity of the front ends of the main weirs 22 and 24. Further, if the length of the main weirs 22 and 24 on the pouring side is extended and bent in the middle as shown in FIG. 6 to form the inclined channel 40, it is not necessary to pour hot water directly above the water-cooled rotary roll 14. Work becomes easy.

  As shown in FIG. 2, the pair of horizontal weirs 42, 44 constituting the weir 20 prevents leakage of the molten metal 16, contacts the ends of the main weirs 22, 24, and is water-cooled in the same manner as the main weirs 22, 24. It extends above the rotary rolls 12 and 14. Further, the horizontal weirs 42 and 44 are in contact with both end faces of the water-cooled rotary rolls 12 and 14 and must withstand friction with the both end faces. In the embodiment, for this purpose, the inner surfaces of the horizontal weirs 42 and 44 use a silica fiber cloth heat insulating material, like the main weirs 22 and 24, while a cushion between the iron plate of the horizontal weirs 42 and 44 and the heat insulating material. There is a thick insulating material. Alternatively, a stainless mesh coated with vermiculite is disposed on the inner surfaces of the horizontal weirs 42 and 44. If the side weirs 42 and 44 are structured to press against the end surfaces of the water-cooled rotary rolls 12 and 14 with a weak force of 4.9 to 9.8 N by a spring having a small spring constant, leakage of the molten metal is prevented while preventing excessive wear. Can be prevented. Similar to the main weirs 22 and 24, the side surfaces of the pair of horizontal weirs 42 and 44 may be disposed with a gap of 2 mm or less with respect to the end surfaces of the water-cooled rotary rolls 12 and 14.

  In twin roll casting, it is important to control the pouring temperature, so the material melted at a higher temperature is transferred to a container near the water-cooled rotary rolls 12 and 14 and allowed to cool naturally by directly measuring the temperature with a thermocouple. Pour hot water as soon as the temperature is reached. It is natural to scoop off the oxide film floating on the surface of the container, but in the case of metal / ceramic composite materials, it is precipitated due to the difference in specific gravity by stirring carefully so as not to disturb the liquid surface. It is also necessary to disperse the ceramic particles.

  If the solidified sheet 18 exiting the gap between the water-cooled rotary rolls 12 and 14 is pulled down as it is, it is torn off by its own weight or a pulling force is applied to the unsolidified portion, so that it is quickly pulled in the lateral direction. Specifically, as shown in FIG. 6, a guide plate 46 bent with a curvature larger than that of the water-cooled rotary rolls 12 and 14 is arranged immediately below the water-cooled rotary rolls 12 and 14, and the solidified sheet 18 is taken up while still hot. . It is desirable to further dispose the roll conveyor 48 at the tip of the guide plate 46 because the sheet 18 is not damaged and the residual heat dissipation efficiency of the sheet 18 is increased.

  As described above, according to the twin roll type vertical casting apparatus 10 of the embodiment, by providing the weir 20 on the water-cooled rotary rolls 12, 14, the liquid surface of the molten metal 16 is positioned above the water-cooled rotary rolls 12, 14. What is necessary is just to control, that is, since the liquid level of the molten metal 16 can be easily controlled, the solidification rate of the molten metal 16 can be controlled to be constant even if the peripheral speed of the water-cooled rotary rolls 12 and 14 is increased. Thereby, the sheet | seat 18 with stable thickness and quality can be extract | collected at high speed, without being influenced by the state of the liquid level of the molten metal 16. FIG.

  Further, the water-cooled rotary rolls 12 and 14 of the twin roll type vertical casting apparatus 10 adopt a roll material having a thermal conductivity of 15 W / m · K or more and a peripheral speed set to 10 m / min or more. The cooling capacity is preferably increased. The peripheral speed is more preferably 20 m / min or more, and the peripheral speed is further preferably 50 m / min or more. Explaining this case, when the water-cooled rotary rolls 12 and 14 are rotated at a high speed at a peripheral speed of 10 m / min or more in order to collect the sheet 18 at a high speed, the thermal conductivity of the water-cooled rotary rolls 12 and 14 is 15 W. If it is less than / m · K, the molten metal 16 may be sent in an unsolidified state from below the water-cooled rotary rolls 12, 14, which is not preferable for manufacturing the sheet 18. Therefore, the sheet | seat 18 can be extract | collected at high speed by employ | adopting that whose heat conductivity is 15 W / m * K or more as a material of the water-cooled rotary rolls 12 and 14. As a material of the water-cooled rotary rolls 12 and 14, a material having a thermal conductivity of 150 W / m · K or more is more preferable. Further, even when a material having a thermal conductivity of 15 W / m · K or more is adopted, it is more preferable to reduce the thickness in order to increase the cooling capacity. For example, in the case of the water-cooled rotating rolls 12 and 14 made of mild steel, it is preferable to set the thickness of the portion in contact with the molten metal to 10 mm or less.

  Furthermore, in the twin roll type vertical casting apparatus 10, it is preferable that the molten metal temperature in the weir 20 is measured by a thermocouple and set to a temperature that is 20 ° C. lower than the metal liquidus temperature and 30 ° C. higher. Explaining this reason, if the temperature exceeds 30 ° C. from the liquidus temperature at which the metal changes from solid to liquid, there is a possibility that the molten metal 16 cannot be solidified reliably by the water-cooled rotary rolls 12, 14. When the temperature is lower than 20 ° C., the molten metal 16 may solidify before the molten metal 16 is supplied to the weir 20. For this reason, it is preferable to set the molten metal temperature in the weir 20 to a temperature 30 ° C. higher than the temperature 20 ° C. lower than the liquidus temperature of the metal. More preferably, the molten metal temperature is set to a temperature 15 ° C. or lower than the liquid phase temperature, and more preferably set to a temperature 10 ° C. or lower than the liquid phase temperature. On the other hand, the molten metal temperature is more preferably set to a temperature that is 25 ° C. higher than the liquidus temperature, and more preferably set to a temperature that is 20 ° C. higher than the liquidus temperature. This setting is particularly effective when the peripheral speed of the water-cooled rotary rolls 12 and 14 is 10 m / min or more and the roll material has a thermal conductivity of 15 W / m · K or more.

  On the other hand, the composite material sheet 18 collected by the twin roll type vertical casting apparatus 10 is preferably further cold-rolled. That is, for example, when it is desired to obtain a sheet 18 having a thickness of 3 mm or less, it can be obtained by cold rolling the composite material sheet 18 collected by the water-cooled rotary rolls 12 and 14. This is because the thickness of the sheet 18 manufactured by the twin roll type vertical casting apparatus 10 is limited.

  Moreover, in cold rolling, it is preferable that the conditions set the rolling reduction per pass to 3 to 10%. Here, the rolling reduction is a value obtained by dividing a value obtained by subtracting the sheet thickness after rolling from the sheet thickness before rolling by the sheet thickness before rolling and multiplying the value by 100. The reason for this will be explained. When the rolling reduction per cold rolling condition is less than 3%, there is a risk that the productivity of the sheet may be deteriorated because the amount of reduction in thickness is small and the number of passes increases. This is because if the rate exceeds 10%, the sheet may break. Therefore, it is preferable that the cold rolling conditions are set to a reduction rate of 3 to 10% per pass.

  Furthermore, it is preferable to perform hot rolling before cold rolling. If the sheet 18 cast by the water-cooled rotary rolls 12 and 14 is hot-rolled before being cold-rolled, the thickness variation (unevenness) of the sheets 18 cast by the water-cooled rotary rolls 12 and 14 can be taken. it can.

  Furthermore, it is preferable that the preheating temperature of the hot rolling is 65 to 85% of the liquidus temperature of the metal, and the rolling reduction per pass is set to 10 to 20%. Explaining this reason, if the preheating temperature of the hot rolling is less than 65% of the liquidus temperature of the metal, it is difficult to take a variation in the thickness of the sheet because the sheet at the time of hot rolling is too hard. If the liquidus temperature exceeds 85%, the sheet becomes too soft, and this also makes it difficult to obtain variations in sheet thickness. Therefore, it is preferable that the preheating temperature of hot rolling is 65 to 85% (preferably 75 to 80%) of the liquidus temperature of the metal.

  Moreover, if the rolling reduction per pass of the hot rolling is less than 10%, it is difficult to reliably take the variation in the thickness of the sheet 18 cast by the water-cooled rotary rolls 12 and 14, and the per rolling per pass. If the rolling reduction exceeds 20%, the sheet 18 may be cracked. Therefore, the hot rolling conditions are preferably set to 10 to 20% rolling reduction per pass.

  FIG. 7 is a side view showing the configuration of the twin roll casting apparatus of the second embodiment. In the twin roll type vertical casting apparatus shown in the figure, a funnel-shaped container 50 is installed above the weir 20, a molten metal 16 is supplied to the container 50, and a piston 54 that opens and closes a lower opening 52 of the container 50. Is a device in which the molten metal 16 is supplied to the weir 20, and the piston 54 is moved downward to close the lower opening 52 to stop the supply of the molten metal 16 to the weir 20.

  In this structure, an upper limit melt level gauge 56 and a lower limit level gauge 58 are attached to predetermined positions of the main weirs 22 and 24 or the horizontal weirs 42 and 44, and the melt level in the weir 20 is lower limit level gauge. When detected by 58, the piston 54 is moved upward to supply the molten metal 16 to the weir 20, and when the molten liquid level in the weir 20 is detected by the upper limit liquid level meter 56, the piston 54 Is moved downward to stop the supply of the molten metal 16. Thereby, supply / stop of supply of the molten metal 16 into the weir 20 can be automated. Needless to say, the mounting position of the upper limit liquid level gauge 56 and the lower limit liquid level gauge 58 is above the water-cooled rotary rolls 12 and 14 in order to facilitate liquid level control.

  A twin roll type vertical casting apparatus equipped with a water-cooled rotating roll made of SS400 steel (plate thickness: 7 mm) (heat conductivity: 50 W / m · K) having a diameter of 300 mm and a width of 300 mm was produced. A hypereutectic Al-Si alloy containing 15% silicon in aluminum by weight (liquidus temperature: 595 ° C) was dissolved in a crucible and cooled to 620 ° C. Molten metal was poured into the weir at 40 m / min, and an intermediate sheet having a width of 300 mm and a thickness of 3 mm was collected. The main weir and the side weir were kept in contact with the water-cooled rotating roll.

  The intermediate sheet was held at 200 ° C. for 30 minutes in an electric furnace to remove distortion caused by rapid cooling, and then cold rolled by a 10-pass cold rolling at room temperature in a 4-stage rolling mill at room temperature of 7% to 1.5 mm. The final sheet product was obtained. That is, according to the present invention, rapid solidification can be performed easily, and the intermediate sheet has a structure composed of fine crystals. Therefore, a reduction ratio of 7%, which could not be achieved with an intermediate sheet using a conventional roll, was possible, and a desired final sheet product was obtained with a small number of passes.

  Aluminum-5 wt% silicon alloy (liquid phase temperature: 590 ° C.) and silicon carbide powder were mixed at a volume ratio of 80:20 to produce an aluminum alloy / silicon carbide composite (liquid phase temperature: 590 ° C.). This was heated and dissolved in a crucible.

  The same water-cooled rotating roll as in Example 1 was used, a silica fiber cloth was bonded to the side in contact with the roll of the mild steel main weir, and a foam ceramic heat insulating material was stretched over the entire inner surface of the main weir. When the composite material was cooled to 610 ° C., molten metal was injected into the weir at a roll rotation speed (circumferential speed) of 60 m / min, and an intermediate sheet having a width of 300 mm and a thickness of 2.5 mm was collected.

  The intermediate sheet is kept in an electric furnace at 200 ° C. for 30 minutes to remove distortion caused by rapid cooling, and then subjected to 14-pass cold rolling at a reduction rate of 5% at room temperature in a four-stage rolling mill. A final sheet product of 5 mm was obtained. That is, according to the present invention, rapid solidification can be performed easily, and the intermediate sheet has a structure composed of fine crystals. Therefore, a reduction ratio of 5%, which could not be achieved with an intermediate sheet using a conventional roll, was possible, and a desired final sheet product was obtained with a small number of passes.

  The metal matrix composite sheet produced in the present invention can be used as a material for a printed circuit board base material by taking advantage of its low coefficient of thermal expansion. Moreover, it can also be utilized as a jig which is repeatedly used as an intermediate plate in a laminated hot press process by utilizing its high thermal conductivity and high rigidity.

The side view which showed the structure of the twin roll type casting apparatus of 1st Embodiment 1 is a perspective view of the main part of the twin roll type vertical casting apparatus shown in FIG. Explanatory diagram using molten metal and a material that is difficult to get wet at the tip of the main weir Explanatory drawing with thermal insulation on the inner surface of the main weir Explanatory drawing showing a state where a solidified layer of material has occurred on the wall of the main weir The side view which showed the modification of the twin roll type casting apparatus of 1st Embodiment The side view which showed the structure of the twin roll type casting apparatus of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Twin roll type vertical casting apparatus, 12, 14 ... Water-cooled rotary roll, 12A, 14A ... Rotary shaft of water-cooled rotary roll, 16 ... Molten metal, 18 ... Sheet, 20 ... Weir, 22, 24 ... Main weir, 26 ... Container, 28 ... Low wettability material, 30 ... Heat insulating material, 32 ... Molten metal block, 34 ... Rail, 36 ... Table, 38 ... Disc spring, 40 ... Inclined flow path, 42, 44 ... Horizontal weir, 46 ... Guide Plate, 48 ... Roll conveyor, 50 ... Container, 52 ... Lower opening, 54 ... Pisunton, 56 ... Upper limit melt level gauge, 58 ... Lower limit level gauge

Claims (11)

A twin roll type vertical casting apparatus for producing a material excluding steel and Ni base alloy into a sheet,
Are oppositely disposed with a predetermined interval, for receiving a pair of water-cooled rotary roll mild steel having a thickness of less 10mm parts in contact with the solvent water, the melt of the material in a molten state on said pair of water-cooled rotating rolls And the weirs are arranged in a direction orthogonal to the pair of plate-like main weirs parallel to the rotation axis of the pair of water-cooled rotary rolls and the rotation axis of the pair of water-cooled rotary rolls. And a pair of lateral weirs connected to both end surfaces of the pair of main weirs,
The lower ends of the one pair of main weirs contact the surface of one of the water-cooled rotary rolls of the pair of water-cooled rotary rolls or form a gap of 2 mm or less, and the lower ends of the pair of other main weirs are the pair of water-cooled rotary rolls Contact with the surface of the other water-cooled rotary roll of the roll or form a gap of 2 mm or less, the side surfaces of the pair of horizontal weirs contact the end face of the water-cooled rotary roll or form a gap of 2 mm or less,
The pair of main weirs and the pair of horizontal weirs are extended above the pair of water-cooled rotary rolls. The twin roll type vertical casting apparatus according to claim 1, wherein the material is an aluminum silicon alloy or a composite material in which an aluminum silicon alloy and silicon carbide powder are mixed. 3. The twin-roll vertical type according to claim 1, wherein the water-cooled rotary roll has a peripheral speed of 10 m / min or higher, and the water-cooled rotary roll has a thermal conductivity of 15 W / m · K or higher. Casting equipment. 4. A twin-roll vertical casting apparatus according to claim 3, wherein a silica fiber cloth is attached to the contact / gap portion in the vicinity of the weir of the water-cooled rotating roll, and boron nitride or graphite spray is sprayed. . The twin roll type vertical casting apparatus according to claim 3, wherein a heat insulating material is disposed on the weir. Using the twin roll type vertical casting apparatus according to any one of claims 1 to 5, the molten metal is poured into a space surrounded by the pair of main weirs and the pair of horizontal weirs, and the pair of water cooling A method for producing a composite material sheet, wherein the composite material sheet is collected directly and continuously from between the rotating rolls. The method for producing a composite material sheet according to claim 6, wherein the molten metal temperature in the weir is set to a temperature that is 20 ° C. lower than the liquidus temperature of the material and 30 ° C. higher. The method for producing a composite material sheet according to claim 6, wherein the collected composite material sheet is further cold-rolled. As a condition of the cold rolling, the value obtained by subtracting the thickness after rolling from the thickness before rolling is divided by the thickness before rolling, and the value obtained by multiplying the value by 100 is the reduction ratio. The method for producing a composite material sheet according to claim 8, wherein the content is 3 to 10% per pass. The method for producing a composite material sheet according to claim 8 or 9, wherein hot rolling is performed before the cold rolling. The method for producing a composite material sheet according to claim 10, wherein a preheating temperature of the hot rolling is 65 to 85% of a liquidus temperature of the metal, and the rolling reduction per pass is 10 to 20%.

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