阅读说明：本技术 定向凝固装置及定向凝固方法 (Directional solidification device and directional solidification method ) 是由 束国刚 任忠鸣 玄伟东 段方苗 王保军 任兴孚 白小龙 于 2021-08-25 设计创作，主要内容包括：本发明提供了一种定向凝固装置和定向凝固方法。定向凝固装置,包括保温炉、容器、铸模、升降组件和搅拌组件。保温炉具有保温腔,容器位于保温炉的下方,容器中装有固态冷却颗粒,铸模能够在保温位置和冷却位置之间往复移动,在保温位置,铸模容置于保温腔中,在冷却位置,铸模浸没在固态冷却颗粒中。升降组件承载铸模以驱动铸模在保温位置和冷却位置之间往复移动。搅拌组件包括搅拌辊,搅拌辊位于容器内并能够通过旋转搅动固态冷却颗粒。采用高导热的固态冷却颗粒作为冷却介质,有利于获得性能优良的定向凝固晶体。搅拌组件对固态冷却颗粒的搅动能够加速铸模的冷却,提高冷却强度和温度梯度,进而有利于定向凝固。(The invention provides a directional solidification device and a directional solidification method. The directional solidification device comprises a holding furnace, a container, a casting mold, a lifting assembly and a stirring assembly. The holding furnace has a holding cavity, a container is located below the holding furnace, solid cooling particles are contained in the container, and the casting mold can reciprocate between a holding position where the casting mold is contained in the holding cavity and a cooling position where the casting mold is immersed in the solid cooling particles. The lifting assembly carries the mold to drive the mold to reciprocate between a holding position and a cooling position. The stirring assembly includes a stirring roller that is located within the container and is capable of agitating the solid state cooled particles by rotation. The solid cooling particles with high heat conductivity are used as a cooling medium, so that the directional solidification crystal with excellent performance can be obtained. The stirring of stirring subassembly to solid-state cooling particle can accelerate the cooling of casting mould, improves cooling strength and temperature gradient, and then is favorable to directional solidification.)

1. A directional solidification apparatus, comprising:

the heat preservation furnace is provided with a heat preservation cavity;

a container located below the holding furnace, the container being filled with solid cooling particles;

a mold reciprocally movable between a soak position in which the mold is received in the soak chamber and a cool down position in which the mold is immersed in the solid cooled particles;

a lifting assembly carrying the casting mold for driving the casting mold to reciprocate between the keep warm position and the cool down position; and

an agitation assembly comprising an agitation roller positioned within the container and capable of agitating the solid state cooled particles by rotation.

2. The directional solidification apparatus of claim 1 further comprising a cooling tray positioned below the mold and carrying the mold, the lift assembly being connected to the cooling tray for moving the mold via the cooling tray.

3. The directional solidification device according to claim 2 wherein a cooling water flow passage is provided inside the cooling tray, the directional solidification device further comprising a water inlet pipe and a water outlet pipe connected to the cooling tray, the cooling water flow passage communicating with each of the water inlet pipe and the water outlet pipe.

4. A directional solidification device according to claim 2 wherein the lifting assembly includes a support bar, a truss and a drive control system, the truss being located below the cooling tray, the support bar connecting the truss and the cooling tray, the drive control system driving and controlling raising and lowering of the truss to ultimately move the mold.

5. The directional solidification device according to claim 1, wherein the stirring rollers include two stirring rollers, central axes of the two stirring rollers are parallel to each other, projections of the two stirring rollers on a horizontal plane are located on two sides of a projection of the casting mold on the horizontal plane, and rotation directions of the two stirring rollers are opposite.

6. The directional solidification device according to claim 5, wherein the stirring roller comprises a driving roller and a driven roller which rotate in opposite directions, the stirring assembly comprises a motor, a driving gear and a driven gear, the motor is connected with the driving roller and can drive the driving roller to rotate, one end of the driving roller is connected with the driving gear, one end of the driven roller is connected with the driven gear, and the driving gear is meshed with the driven gear.

7. The directional solidification device of any one of claims 1 to 6 wherein the agitator assembly further comprises a toothed plate or vane mounted on a circumferential surface of the agitator roller.

8. The directional solidification device of claim 1 wherein a water cooling channel is provided in the wall of the vessel.

9. The directional solidification device according to claim 1, further comprising an annular heat insulating plate connected below the holding furnace, wherein the casting mold is sleeved with the annular heat insulating plate, and the annular heat insulating plate isolates the holding cavity from the solid cooling particles.

10. A directional solidification method, characterized in that directional solidification is performed using the directional solidification apparatus according to any one of claims 1 to 9, comprising the steps of:

step 1: the lifting assembly enables the casting mould to be in the heat preservation position, and the casting mould is preheated in the heat preservation cavity;

step 2: injecting a molten superalloy into the casting mold;

and step 3: moving the casting mold to the cooling position by using the lifting assembly, wherein the casting mold is gradually immersed by the solid cooling particles in the container and exchanges heat with the solid cooling particles to gradually cool, solidify and form the high-temperature alloy in the casting mold from bottom to top, and the stirring roller rotates to enable the solid cooling particles which are around the casting mold and absorb heat to be far away from the casting mold and bring the solid cooling particles with lower temperature to the vicinity of the casting mold;

and 4, step 4: the casting mold stays for a preset time after reaching the cooling position until the alloy in the casting mold is completely solidified and formed;

and 5: and after the alloy is completely solidified and formed, taking out the casting mold and the solidified alloy and demolding.

11. The directional solidification method according to claim 10, wherein directional solidification is performed using the directional solidification apparatus according to claim 7, the directional solidification method further comprising the steps of:

the motor drives the driving roller to rotate, the driving roller drives the driven roller to rotate in the opposite direction through the driving gear and the driven gear, the solid cooling particles flow from top to bottom along the surface of the casting mold,

this step is performed simultaneously with step 3.

12. The directional solidification method of claim 11 further comprising the step of 6: and (3) loading a new casting mold, moving the new casting mold to the heat preservation position by the lifting assembly, driving the driving roller to rotate reversely by the motor, driving the driven roller to rotate reversely by the driving roller, enabling the solid cooling particles to flow along the surface of the casting mold from bottom to top, and repeating the step (1) to the step (5).

Technical Field

The invention relates to the technical field of directional solidification, in particular to a directional solidification device and a directional solidification method.

Background

The directional solidification technology is used as a main method in the preparation process of columnar crystals and single crystals, and has a high position in the field of advanced high-performance material processing and preparation. The directional solidification technology is widely applied to the production of high-temperature alloy blades of gas turbines and aviation generators.

The temperature gradient is a key factor influencing the growth speed of the crystal and the structure and performance quality of the crystal, and the high temperature gradient is beneficial to obtaining excellent columnar crystal structure or single crystal structure, refining dendritic crystal, reducing segregation and improving the comprehensive performance of the alloy. Therefore, how to increase and precisely control the temperature gradient becomes an important part of the directional solidification technology.

The traditional directional Solidification process such as High Rate Solidification (HRS) uses baffles to isolate the hot end and the cold end, but for the production of large-size directional blades, the temperature gradient and the Solidification speed of the traditional directional Solidification process cannot meet the requirements. Therefore, Liquid Metal Cooling (LMC) is mostly adopted in the related art, and low-melting-point Liquid Metal is used as a Cooling medium to improve the Cooling strength, but the Liquid Metal Cooling method is complex in technology, difficult in process control, and easy to cause high-temperature alloy pollution and reduce the quality and performance of the blade.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, embodiments of the present invention propose a directional solidification apparatus and a directional solidification method.

The directional solidification device according to an embodiment of the present invention includes: the heat preservation furnace is provided with a heat preservation cavity; a container located below the holding furnace, the container being filled with solid cooling particles; a mold reciprocally movable between a soak position in which the mold is received in the soak chamber and a cool down position; in the cooling position, the casting mold is immersed in the solid cooling particles; a lifting assembly carrying the casting mold for driving the casting mold to reciprocate between the keep warm position and the cool down position. The directional solidification apparatus further includes an agitation assembly including an agitation roller located within the container and capable of agitating the solid state cooled particles by rotation.

According to the directional solidification device provided by the embodiment of the invention, the solid cooling particles with high heat conductivity are used as the cooling medium, when the casting mould moves from the heat preservation position to the cooling position, the lower end of the casting mould is gradually immersed in the solid cooling particles and is in contact with the solid cooling particles to perform heat exchange so as to be cooled, and a stable temperature gradient in a single direction is formed in the casting mould, so that directional solidification crystals with excellent performance are obtained. In addition, the solid cooling particles can isolate heat in the holding furnace from radiating and heating solidified crystal parts in the casting mould, so that the temperature gradient can be further improved. The stirring of stirring subassembly to solid-state cooling particle can accelerate the cooling of casting mould, improves cooling strength and temperature gradient, and then is favorable to directional solidification.

In addition, the directional solidification device according to the invention has the following additional technical features:

in some embodiments, the directional solidification apparatus further includes a cooling tray located below the casting mold and carrying the casting mold, and the lifting assembly is connected to the cooling tray so as to move the casting mold via the cooling tray.

In some embodiments, the cooling tray is provided with a cooling water flow passage inside, and the directional solidification device further includes a water inlet pipe and a water outlet pipe connected to the cooling tray, the cooling water flow passage being in communication with each of the water inlet pipe and the water outlet pipe.

In some embodiments, the lifting assembly includes a support bar, a truss, and a drive control system, the truss being located below the cooling tray, the support bar connecting the truss and the cooling tray, the drive control system driving and controlling the raising and lowering of the truss to ultimately move the mold.

In some embodiments, the stirring rollers include two stirring rollers, central axes of the two stirring rollers are parallel to each other, projections of the two stirring rollers on a horizontal plane are respectively located on two sides of a projection of the casting mold on the horizontal plane, and rotation directions of the two stirring rollers are opposite.

In some embodiments, the stirring roller includes a driving roller and a driven roller with opposite rotation directions, the stirring assembly includes a motor, a driving gear and a driven gear, the motor is connected to the driving roller and can drive the driving roller to rotate, one end of the driving roller is connected to the driving gear, one end of the driven roller is connected to the driven gear, and the driving gear is engaged with the driven gear.

In some embodiments, the blending assembly further comprises a toothed plate or vane mounted on a circumferential surface of the blending roller.

In some embodiments, a water cooling channel is provided in the wall of the container.

In some embodiments, the directional solidification device further comprises an annular heat insulation plate, the annular heat insulation plate is connected below the holding furnace, the annular heat insulation plate is sleeved on the casting mold, and the annular heat insulation plate isolates the holding cavity from the solid cooling particles.

According to another aspect of the present invention, there is provided a directional solidification method using the directional solidification apparatus provided in any one of the above embodiments, including the steps of:

step 1: the lifting assembly enables the casting mould to be in the heat preservation position, and the casting mould is preheated in the heat preservation cavity;

step 2: injecting a molten superalloy into the casting mold;

and step 3: moving the casting mold to the cooling position by using the lifting assembly, wherein the casting mold is gradually immersed by the solid cooling particles in the container and exchanges heat with the solid cooling particles so as to gradually cool, solidify and form the high-temperature alloy in the casting mold from bottom to top;

and 4, step 4: the casting mold stays for a preset time after reaching the cooling position until the alloy in the casting mold is completely solidified and formed;

and 5: and after the alloy is completely solidified and formed, taking out the casting mold and the solidified alloy and demolding.

In some embodiment modes, the directional solidification method further comprises the steps of: the stirring roller rotates to make the solid cooling particles which are positioned around the casting mould and absorb heat far away from the casting mould and bring the solid cooling particles with lower temperature to the vicinity of the casting mould, and the step is carried out simultaneously with the step 3.

In some embodiment modes, the directional solidification method further comprises the steps of: the motor drives the driving roller to rotate, the driving roller drives the driven roller to rotate in the opposite direction through the driving gear and the driven gear, and the solid cooling particles flow from top to bottom along the surface of the casting mold, and the step 3 are carried out simultaneously.

In some embodiment modes, the method further comprises the step 6: and (3) loading a new casting mold, moving the new casting mold to the heat preservation position by the lifting assembly, driving the driving roller to rotate reversely by the motor, driving the driven roller to rotate reversely by the driving roller, enabling the solid cooling particles to flow along the surface of the casting mold from bottom to top, and repeating the step (1) to the step (5).

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a front view of a directional solidification apparatus according to an embodiment of the present invention.

FIG. 2 is a top view of a directional solidification apparatus according to an embodiment of the present invention.

Reference numerals:

a directional solidification apparatus 100;

a holding furnace 110; a heat preservation chamber 111; a heat generating member 112; an upper cover 113; a container 120; a mold 130; a support rod 141; a truss 142; a cooling tray 150; a drive roller 161; a driven roller 162; a motor 163; a drive gear 164; a driven gear 165; a drive gear 166; toothed plate 167; an annular heat shield 170; the solid state cools the particles 200.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The basic structure of the directional solidification apparatus 100 provided by the present invention will be described with reference to fig. 1 and 2.

As shown in fig. 1, the directional solidification apparatus 100 includes a holding furnace 110, a container 120, a mold 130, and a lifting assembly. Wherein the holding furnace 110 defines a holding chamber 111. The container 120 is located below the holding furnace 110, and the accommodating cavity of the container 120 is filled with the solid cooling particles 200 for cooling the casting mold 130.

The mold 130 is capable of reciprocating between a soak position and a cool down position. Wherein, in the heat-preserving position, the casting mold 130 is accommodated in the heat-preserving chamber 111 for heat preservation, and in the cooling position, the casting mold 130 is immersed in the solid cooling particles for cooling. It is understood that in the directional solidification apparatus 100 provided by the present invention, the holding chamber 111 of the holding furnace 110 serves as a hot end for directional solidification, and the solid cooling particles 200 installed in the container 120 serve as a cold end for directional solidification, and when the mold 130 moves from the holding position to the cooling position, that is, when a portion of the lower end of the mold 130 is extracted from the holding chamber 111 and submerged in the solid cooling particles 200 in the container 120, since the upper half of the mold 130 is located in the holding chamber 111, a stable directional temperature gradient is formed in the mold 130 by the hot end and the cold end, and thus the alloy in the mold 130 can be gradually solidified and formed in the direction of the temperature gradient. It should be noted that the solid cooling particles 200 are solid particles with high thermal conductivity, which perform efficient heat exchange between the cold end and the mold 130 in contact therewith to cool the mold 130 with a high temperature, and have excellent cooling capability.

The lifting assembly is used for carrying the casting mold 130 to drive the casting mold 130 to move back and forth between the heat preservation position and the cooling position, namely, the casting mold 130 can be lifted or lowered under the action of the lifting assembly to realize the back and forth movement between the heat preservation position and the cooling position. As the mold 130 is lowered by the lifting assembly, the mold 130 is gradually pulled out of the soak chamber 111 and immersed in the solid cooled granules 200 in the container 120. As the mold 130 is raised by the lifting assembly, the mold 130 immersed in the solid cooling particles 200 is gradually pulled out and extended into the soak chamber 111.

The directional solidification apparatus 100 further includes an agitation assembly including an agitation roller positioned within the container 120, the agitation roller being capable of agitating the solid cooled particles 200 in the container 120 by rotation. The agitation of the solid cooling particles 200 can make the solid cooling particles 200, which are near the casting mold 130 and whose temperature is raised due to heat absorption, far away from the casting mold 130, and at the same time, make the solid cooling particles 200, which are far away from the casting mold 130 and not contacted with the casting mold 130 to absorb heat, which are lower in temperature, close to the casting mold 130 and contact-cool the casting mold 130, thereby ensuring that the surface of the casting mold 130 is always contacted with the cold solid cooling particles 200, accelerating the cooling of the casting mold 130, improving the cooling strength and the temperature gradient, and further facilitating the directional solidification. Alternatively, the stirring roller may be one or more.

According to the directional solidification device provided by the embodiment of the invention, the solid cooling particles with high heat conductivity are used as the cooling medium, when the casting mould moves from the heat preservation position to the cooling position, the lower end of the casting mould is gradually immersed in the solid cooling particles and is in contact with the solid cooling particles to perform heat exchange so as to be cooled, and a stable temperature gradient in a single direction is formed in the casting mould, so that directional solidification crystals with excellent performance are obtained. In addition, the solid cooling particles can isolate heat in the holding furnace from radiating and heating solidified crystal parts in the casting mould, so that the temperature gradient can be further improved. The stirring of stirring subassembly to solid-state cooling particle can accelerate the cooling of casting mould, improves cooling strength and temperature gradient, and then is favorable to directional solidification.

The invention also provides a method for directional solidification by using the directional solidification device 100, which comprises the following steps:

step 1: the lifting assembly enables the casting mould 130 to be at a heat preservation position, and the casting mould 130 is preheated in the heat preservation cavity 111;

step 2: injecting the molten superalloy into the mold 130;

and step 3: moving the casting mold 130 to a cooling position by using the lifting assembly, wherein the casting mold 130 is gradually immersed by the solid cooling particles 200 in the container 120 and exchanges heat with the solid cooling particles 200 to gradually cool, solidify and form the high-temperature alloy in the casting mold 130 from bottom to top;

and 4, step 4: the casting mold 130 stays for a preset time after reaching the cooling position until the alloy in the casting mold 130 is completely solidified and formed;

and 5: after the alloy is completely solidified and formed, the mold 130 and the solidified alloy are taken out and demolded.

According to the directional solidification method provided by the embodiment of the invention, the casting mold is cooled by adopting the solid cooling particles, so that the high-temperature alloy in the casting mold is directionally solidified and formed under the temperature gradient in a single direction. In addition, the solid cooling particles can isolate heat in the holding furnace from radiating and heating solidified crystal parts in the casting mould, so that the temperature gradient can be further improved.

A specific embodiment of the present invention will be described below with reference to fig. 1 and 2.

As shown in fig. 1, the directional solidification apparatus 100 of the present embodiment includes a holding furnace 110, a container 120, a mold 130, and a lifting assembly. The container 120 is positioned below the holding furnace 110, and the accommodating cavity of the container 120 is filled with the solid cooling particles 200. The mold 130 is moved up and down by the elevating assembly between a holding position in the holding chamber 111 of the holding furnace 110 and a cooling position in the container 120. Optionally, the vessel 120 is made of steel.

In the embodiment shown in fig. 1, in order to better keep the temperature of the casting mold 130, a heat generating member 112 for heating and keeping the temperature is further provided in the holding furnace 110. Specifically, the heat generating member 112 is disposed around the sidewall of the holding furnace 110, and the temperature of the heat generating member 112 is increased after being energized, and the heat is radiated to the mold 130 to be increased and maintained at a predetermined temperature. The upper end of the holding furnace 110 is provided with an upper cover 113, and the upper cover 113 can prevent the heat in the protection cavity 111 from dissipating. The holding furnace 110 is open at the lower end, and the mold 130 can extend into or out of the holding chamber 111 through the lower end opening of the holding furnace 110.

Further, the directional solidification apparatus 100 further includes an annular heat insulation plate 170, the annular heat insulation plate 170 is connected below the holding furnace 110, the annular heat insulation plate 170 is sleeved on the casting mold 130, and the annular heat insulation plate 170 is used for isolating the high-temperature holding cavity 111 from the low-temperature solid-state cooling particles 200 and preventing the heat in the holding cavity 111 from being excessively radiated downwards to the solid-state cooling particles 200. Optionally, the annular insulating plate 170 is made of a carbon anvil or an insulating ceramic material.

Optionally, the solid state cooling particles 200 are highly thermally conductive metal particles.

The directional solidification apparatus 100 of the present embodiment further includes a cooling tray 150, the cooling tray 150 is located below the casting mold 130 and carries the casting mold 130, and the casting mold 130 is placed on the cooling tray 150. The lifting assembly is connected to the cooling tray 150 so as to move the mold 140 up and down by moving the cooling tray 150, i.e., the lifting assembly moves the mold 140 and the cooling tray 150 synchronously by moving the cooling tray 150.

In this embodiment, the mold 130 is a cylindrical mold with an open top and a closed bottom, the mold 130 is placed on the cooling tray 150, the upper surface of the cooling tray 150 seals the lower opening of the mold 130 to prevent the leakage of the high temperature alloy, and the upper opening of the mold 130 is used for pouring the molten high temperature alloy into the mold 130. The cooling tray 150 is used to further cool the lower end of the mold 130, increasing the temperature gradient during directional solidification.

Further, the cooling tray 150 is a water-cooling tray, a cooling water flow channel (not shown in the figure) is arranged in the cooling tray 150, the directional solidification device 100 further comprises a water inlet pipe (not shown in the figure) and a water outlet pipe (not shown in the figure), the water inlet pipe and the water outlet pipe are both connected with the cold area tray 150, the water inlet end of the water inlet pipe is communicated with the water inlet end of the cooling water flow channel so as to introduce cooling water into the cooling water flow channel, the water outlet pipe is communicated with the water outlet end of the cooling water flow channel so as to discharge the cooling water in the cooling water flow channel, heat is continuously taken away by the cooling water flowing in the cooling water flow channel, the cooling tray 150 is kept at a lower temperature, the casting mold 130 is continuously and effectively cooled, the temperature gradient in the directional solidification process is ensured, the directional growth of crystals is facilitated, and the preparation of single crystal blades with excellent performance is facilitated.

In this embodiment, as shown in fig. 1, the lifting assembly specifically includes a support bar 141, a truss 142 and a driving control device (not shown), wherein the truss 142 is located below the cooling tray 150, an upper end of the support bar 141 is connected to a lower surface of the cooling tray 150, and a lower end of the support bar 141 is connected to the truss 142. The drive control device is used for driving and controlling the lifting and the descending of the truss 142, so as to drive the lifting and the descending of the cooling tray 150, and finally drive the casting mould 130 to reciprocate between the heat preservation position and the cooling position.

Further, water cooling channels are provided in the wall of the container 120, and the wall of the container 120 can cool the solid cooling particles 200. When the solid cooling particles 200 having absorbed heat and increased in temperature contact with the wall of the container 120 by the stirring roller, the wall of the container 120 absorbs heat from the solid cooling particles 200 to lower the temperature of the solid cooling particles 200 to the initial cooling temperature, and then the cooled solid cooling particles 200 are carried to the casting mold 130 by the stirring roller to continue cooling, so that the circulation can accelerate cooling of the casting mold 130 to further improve cooling intensity and temperature gradient.

Specifically, as shown in fig. 2, the stirring rollers include a drive roller 161 and a driven roller 162 whose central axes are parallel to each other, wherein projections of the drive roller 161 and the driven roller 162 on the horizontal plane are located on both sides of a projection of the mold 130 on the horizontal plane, respectively. The drive roller 161 and the driven roller 162 are aligned in the up-down direction, that is, the central axis of the drive roller 161 and the central axis of the driven roller 162 are located on the same horizontal plane, so that the structure is more reasonable.

In addition, in the present embodiment, as shown in fig. 1, the drive roller 161 and the driven roller 162 are disposed at a position near the bottom of the container 120. When mold 130 is in the keep warm position, drive roll 161 and driven roll 162 are both located below truss 142. When the mold 130 is in the cooling position, the drive roller 161 and the driven roller 162 are both located below the mold 130. As shown in fig. 2, the projection of the truss 142 on the horizontal plane is located in the middle of the projections of the driving roller 161 and the driven roller 162 on the horizontal plane, and the truss 142 can extend between the driving roller 161 and the driven roller 162 during the descending process, so that the driving roller 161 and the driven roller 162 arranged in the container 120 do not affect the movement of the truss 142.

The stirring assembly further comprises a motor 163, a driving gear 164, a driven gear 165 and two transmission gears 166, the motor 163 is connected with the driving roller 161 and can drive the driving roller 161 to rotate, one end of the driving roller 161 is connected with the driving gear 164, one end of the driven roller 162 is connected with the driven gear 165, and the driving gear 164 is meshed with the driven gear 165 through the two transmission gears 166. When the stirring assembly is operated, the motor 163 drives the driving gear 164 to rotate synchronously with the driving roller 161 by driving the driving roller 161 to rotate, the driving gear 164 transmits a driving force to the driven gear 165 through the two parallel transmission gears 166, the driven gear 165 rotates to drive the driven roller 162 to rotate, and it can be understood that the driving roller 161 and the driven roller 162 rotate in opposite directions.

It should be noted that, in other embodiments, the driving roller 161 and the driven roller 162 may have other driving manners, for example, the driving gear 164 is directly engaged with the transmission gear 166, and mutual reverse rotation of the driving roller 161 and the driven roller 162 may also be achieved, or the stirring assembly may include two motors and two driving rollers, the two motors are respectively connected to the two driving rollers, there is no transmission relationship between the two driving rollers, and the two motors drive the two driving rollers to rotate in opposite directions, and also may achieve the above functions.

The solid cooling particles 200 may be regularly agitated by reversing the rotation direction of the driving roller 161 and the driven roller 162. As described above, since the projections of the driving roll 161 and the driven roll 162 on the horizontal plane are respectively located on both sides of the projection of the mold 130 on the horizontal plane, the rotation of the driving roll 161 and the driven roll 162 enables the solid cooling particles 200 to better flow on the surface of the mold 130, improving the cooling effect thereof.

Alternatively, when the casting mold 130 is lowered, i.e., moved to the cooling position, by the lifting assembly, as shown in the right view of fig. 2, the driving roller 161 is rotated clockwise, and the driven roller 162 is rotated counterclockwise, so that the solid cooling particles 200 below the truss 142 are moved away to both sides, the resistance of the solid cooling particles 200 to the truss 142 is reduced, and the solid cooling particles 200 are continuously moved along the surface of the casting mold 130 from top to bottom, thereby cooling the casting mold 130. The heated solid cooling particles 200 flow to the vicinity of the bottom wall and the side wall of the container 120 by the stirring action of the driving roller 161 and the driven roller 162, and are cooled by the bottom wall and the side wall of the container 120. The above cycle is carried out until the directional solidification is finished.

When the mold 130 is raised, i.e. moved to the holding position, by the lifting assembly, taking the right view of fig. 2 as an example, the driving roller 161 is rotated counterclockwise, the driven roller 162 is rotated clockwise, so that the solid cooling particles 200 above the mold 130 are moved away to both sides, and the solid cooling particles 200 are continuously flowed along the surface of the mold 130 from bottom to top, thereby reducing the resistance of the solid cooling particles 200 to the mold 130 and the cooling tray 150.

It should be noted that in other embodiments, the driving roller 161 and the driven roller 162 may have other relative rotation manners, and the number of the driving roller 161 and the driven roller 162 may be multiple, which is not described herein.

Optionally, toothed plates 167 or vanes may also be provided on the circumferential surfaces of the stirring rollers (the driving roller 161 and the driven roller 162) to better agitate the solid cooling particles 200.

The method for performing directional solidification by using the directional solidification device in the embodiment is described below according to the directional solidification device provided in the above-mentioned embodiment, and specifically includes the following steps:

step 1: the lifting assembly enables the casting mold 130 to be at a heat preservation position, and the casting mold 130 is preheated in the heat preservation cavity 111 to reach a preset temperature value;

step 2: injecting the molten superalloy from the upper opening of the holding furnace 110 into the upper opening of the mold 130 in the holding chamber 111, so that the molten superalloy fills the mold 130;

and step 3: the driving control device of the lifting group 140 drives the truss 142 to descend to drive the casting mold 130 to move to the cooling position, in the process, the casting mold 130 is gradually immersed by the solid cooling particles 200 in the container 120, meanwhile, the motor 163 drives the driving roller 161 to rotate, the driving roller 161 drives the driven roller 162 to rotate, the rotating directions of the driving roller 161 and the driven roller 162 are opposite to enable the solid cooling particles 200 below the truss 142 to move away towards two sides, and the solid cooling particles 200 continuously flow along the surface of the casting mold 130 from top to bottom to cool the casting mold 130, and due to continuous heat exchange with the solid cooling particles 200, the high-temperature alloy in the casting mold 130 is gradually cooled and solidified from bottom to top to be formed;

and 4, step 4: the casting mold 130 stays for a preset time after reaching the cooling position until the alloy in the casting mold 130 is completely solidified and formed, and the stay time can be selected according to experience;

and 5: after the alloy in the casting mold 130 is completely solidified and formed, taking out the casting mold 130 and the solidified alloy, and demolding to finish one-time directional solidification;

step 6: a new casting mold 130 is loaded on the cooling tray 150, the driving control device of the lifting assembly 140 drives the truss 142 to ascend so as to move the new casting mold 130 to the heat preservation position, meanwhile, the motor 163 drives the driving roller 161 to rotate reversely, the driving roller 161 drives the driven roller 162 to rotate reversely, so that the solid cooling particles 200 above the casting mold 130 move away to two sides, and the solid cooling particles 200 continuously flow along the surface of the casting mold 130 from bottom to top, so that the resistance of the solid cooling particles 200 to the casting mold 130 and the cooling tray 150 is reduced, and then the steps 1-5 are repeated.

In step 2, the superalloy at the bottom of the mold 130 is cooled and solidified by contacting the cooling tray 150, and the superalloy above the mold 130 is far from the cooling tray 150 and is not greatly affected by the cooling, so that a directional temperature gradient is formed inside the mold 130, and the directional solidification process starts.

In step 3, the solid cooling particles 200, which are located around the mold 130 and absorb heat, are moved away from the mold 130 by the rotation of the driving roll 161 and the driven roll 162, and the solid cooling particles 200, which have a lower temperature, are brought close to the mold 130 to cool the mold. In which the solid cooling particles 200 having a higher temperature away from the mold 130 are in contact with the walls of the container 120, the walls of the container 120 absorb the heat in the solid cooling particles 200 to lower the temperature thereof, and the cooled solid cooling particles 200 are then carried to the vicinity of the mold 130 by the driving roller 161 and the driven roller 162 to continue cooling thereof.

In summary, the directional solidification method provided by the embodiment has the following beneficial effects:

(1) the casting mold is cooled by adopting the solid cooling particles, the process is simple and easy to control, the casting mold and the high-temperature alloy in the casting mold are not polluted, and the quality and the preparation success rate of the directional solidification crystal are improved.

(2) And stirring the solid cooling particles by using a stirring roller to ensure that the surface of the casting mould is always contacted with the cold solid cooling particles, so as to accelerate the cooling of the casting mould.

(3) The wall of the container filled with the solid cooling particles is internally provided with a water cooling channel which can cool the solid cooling particles, accelerate the cooling of the casting mold and further improve the cooling strength and the temperature gradient.

(4) The solid cooling particles can be regularly agitated by reversing the rotational direction of the driving roller and the driven roller. The solid cooling particles can flow on the surface of the casting mould more controllably, and the cooling effect is further improved.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.