CN110614355B - High-temperature heating system for directional solidification and casting of materials in hypergravity environment - Google Patents

Abstract

The invention discloses a high-temperature heating system for directional solidification and casting of materials in a hypergravity environment. The high-gravity test cabin is fixed in the high-gravity test cabin, the furnace body supporting body is arranged at the bottom of the lower cavity heat insulation layer of the lower furnace body, the heating cavity is arranged on the furnace body supporting body, and a mullite heat insulation layer is filled between the heating cavity and the upper cavity heat insulation layer of the upper furnace body, the middle cavity heat insulation layer of the middle furnace body and the lower cavity heat insulation layer of the lower furnace body respectively; the heating cavity is divided into an upper part and a lower part, and is internally provided with a spiral groove and a heating body; the crucible supporting seat is internally provided with a ventilation pipeline for leading in directional solidification cooling gas. The invention can heat the material directional solidification casting sample under the condition of high rotating speed by matching with the hypergravity environment, solves the key problem of directional solidification casting heating under the high-speed rotating state, fills the blank of the domestic technical industry, and has simple equipment and convenient operation.

Description

High-temperature heating system for directional solidification and casting of materials in hypergravity environment

Technical field

The invention relates to the field of high-temperature heating, and in particular to a high-temperature heating of samples suitable for directional solidification and casting of materials in a hypergravity environment.

Background technique

As one of the key components of the hot-end components of aero engines and gas turbines, high-pressure turbine blades work under coupled loading conditions such as high temperature, high pressure, high speed, and alternating loads for a long time during service. They are the rotating parts with the worst working conditions in the engine. Its reliability in use directly affects the performance of the whole machine. In the development process of high-temperature alloys, technology plays a great role in promoting the development of high-temperature alloys. Usually, in order to improve the comprehensive mechanical properties of high-temperature alloys, two approaches are adopted: one is to add a large amount of alloying elements, and use reasonable heat treatment processes to produce solid solution strengthening, precipitation strengthening, and grain boundary strengthening, so as to ensure that the high-temperature alloys have the characteristics Good strength from room temperature to high temperature, indicating stability and good plasticity; the second is to start with the solidification process and use the directional solidification process to prepare columnar grain superalloys with grain boundaries parallel to the principal stress axis to eliminate harmful lateral grain boundaries or prepare Single crystal superalloys that eliminate all grain boundaries.

Due to the elimination of lateral grain boundaries or complete elimination of grain boundaries in oriented and single crystal blades, the crystal grows along the [001] specific direction, increases the initial melting temperature and solution treatment window temperature, increases the number of γ and refines it, greatly improves performance and improves Operating temperature.

Currently, almost all advanced aerospace engines use single crystal superalloys. The rapid solidification method widely used in industry to prepare single crystal alloys has a temperature gradient that can only reach about 100K/cm, and the solidification rate is very low, resulting in a coarse solidified structure and severe segregation, resulting in the material's performance not being fully utilized. Crystal growth under microgravity effectively suppresses the irregular heat and mass convection caused by gravity due to the reduced gravitational acceleration, thereby obtaining crystals with highly uniform solute distribution. However, the cost is too high and cannot be industrialized.

Single crystal alloys can be prepared in a hypergravity environment, but the existing technology lacks a heating system to achieve directional solidification in a hypergravity environment.

Contents of the invention

What the present invention needs to solve is to solve the problem of difficulty in heating samples during the directional solidification and casting process of materials under the above-mentioned hypergravity and high-temperature test conditions. The directional solidification and casting of materials under high-speed-high-temperature coupling environment provides a method that is simple to assemble, easy to use, and has a high safety factor. High temperature heating system that can be used in hypergravity conditions makes it possible to prepare single crystal alloys under hypergravity.

The technical solution adopted by the present invention is:

The high-temperature heating system of the present invention is fixed in the hypergravity test cabin. The high-temperature heating system includes an upper furnace body, a middle furnace body, a lower furnace body, a mullite insulation layer, and an upper heating cavity that are connected in sequence from top to bottom. The outer body, the outer body of the lower heating chamber, the upper heating furnace tube, the lower heating furnace tube, the crucible support seat and the heating element; the upper furnace body mainly consists of the upper heat insulation cover, the upper cavity shell, the upper cavity middle shell, and the upper cavity It consists of a heat insulation layer and a lower fixed cover of the upper cavity. The upper cavity shell, the upper cavity middle shell, and the upper cavity heat insulation layer are installed from the outside to the inside to form a three-layer structure of the upper furnace. The upper heat insulation cover and the upper cavity The lower fixed covers are respectively installed on the upper and lower ends of the three-layer structure of the upper furnace to make the three-layer structure of the upper furnace fixedly connected, between the upper cavity shell and the upper cavity middle shell, and between the upper cavity middle shell and the upper cavity heat insulation layer. There are gaps between them as air heat insulation layers; the middle furnace body is mainly composed of a middle heat insulation cover, a middle cavity shell, a middle cavity middle shell, a middle cavity heat insulation layer, and a middle cavity lower fixed cover. The middle cavity shell , the middle shell of the middle cavity, and the insulation layer of the middle cavity are installed from the outside to the inside to form a three-layer structure of the middle furnace. The middle heat insulation cover and the lower fixed cover of the middle cavity are installed on the upper and lower ends of the three-layer structure of the middle furnace respectively. The three-layer structure of the middle furnace is fixedly connected. There is a gap between the middle cavity shell and the middle cavity middle shell and between the middle cavity middle shell and the middle cavity body insulation layer as an air insulation layer; the upper cavity of the upper furnace body The fixed cover under the body is fixedly connected to the middle heat-insulating cover of the middle furnace body; the lower furnace body is mainly composed of a lower heat-insulating cover, a lower cavity shell, a lower cavity middle shell, a lower cavity heat insulation layer, and a lower cavity lower body. It consists of a fixed cover. The lower cavity shell, the lower cavity middle shell, and the lower cavity heat insulation layer are installed from the outside to the inside to form a three-layer structure of the lower furnace. The lower heat insulation cover and the lower cavity lower fixed cover are installed on the lower furnace respectively. The upper and lower ends of the three-layer structure make the three-layer structure of the lower furnace fixedly connected. There are gaps between the lower cavity shell and the lower cavity middle shell and between the lower cavity middle shell and the lower cavity insulation layer as air insulation. layer; the lower fixed cover of the middle cavity of the middle furnace body is fixedly connected to the lower heat insulating cover of the lower furnace body.

The crucible support seat is placed at the bottom of the heat insulation layer of the lower cavity of the lower furnace body, and the heating cavity is placed on the crucible support seat. The heating cavity includes an upper heating cavity outer body, a lower heating cavity outer body, an upper heating furnace tube and a lower heating chamber. The furnace tube, the outer body of the upper heating chamber and the outer body of the lower heating chamber are all sleeve structures. The outer body of the upper heating chamber and the outer body of the lower heating chamber are located at the upper and lower coaxial fixed joints respectively. The upper heating furnace tube and the lower heating furnace tube are set separately. In the outer body of the upper heating cavity and the outer body of the lower heating cavity, the outer body of the upper heating cavity and the outer body of the lower heating cavity are located in the upper cavity insulation layer of the upper furnace body, the middle cavity insulation layer of the middle furnace body, and the lower furnace body. The heat insulation layer of the lower cavity of the body is filled with a mullite insulation layer; the outer walls of the upper and lower heating furnace tubes are processed with spiral grooves, and the spiral grooves are equipped with spiral heating elements to generate heat. The heat generated by the crucible is evenly radiated to the heating furnace tube composed of the upper heating furnace tube and the lower heating furnace tube, forming a high-temperature zone in the center of the heating furnace tube; there is a ventilation duct inside the crucible support seat, which is used to circulate the cooling gas for directional solidification. In, the upper end of the ventilation pipe penetrates out of the top surface of the crucible support seat as an outlet and is connected to the inside of the lower heating furnace tube, and the lower end of the ventilation pipe penetrates out of the bottom of the crucible support seat as an inlet.

A crucible and a cooling system are installed on the crucible supports inside the upper heating furnace tube and the lower heating furnace tube. The cooling gas of the directional solidification test is passed into the bottom of the crucible through the ventilation pipe, and the bottom of the crucible is cooled to form a super cooling system along the crucible. Directional solidification is performed based on the temperature gradient in the direction of gravity, and the temperature gradient distribution along the direction of supergravity is controlled by regulating the incoming flow rate of the cooling gas and the temperature generated by the heating element.

During the working process, the heating element generates heat, which heats the upper and lower heating furnace tubes through radiation, forming a high-temperature zone in the center of the heating furnace tube. By changing the pitch of the spiral grooves at different heights, the heating elements at different heights are changed. The spacing between the heating furnace tubes, combined with the temperature and flow rate of the cooling gas introduced into the ventilation pipe of the crucible support seat, starts cooling from the bottom of the crucible, forming a temperature gradient along the direction of supergravity.

The upper heating furnace tube and the lower heating furnace tube are made of ceramics with high strength and low thermal conductivity.

The high-temperature heating system is placed in the hypergravity environment of the centrifuge.

The hypergravity experimental cabin is also equipped with a load-bearing frame, a signal collector and a wiring frame. The upper heating furnace tube and the lower heating furnace tube of the high-temperature heating system are equipped with material samples to be directional solidified, and are equipped with temperature sensors. The temperature sensor is connected to the signal collector, and the wire output by the signal collector is connected to the weak signal conductive slip ring through the wiring frame, and then connected to the ground measurement and control center;

The high-temperature heating system is equipped with a strong-current independent circuit. A strong-current independent circuit controls the heating elements at different heights inside for high-temperature heating. A strong-current independent circuit on the ground is connected to the hypergravity experimental cabin through the conductive slip ring of the centrifuge spindle. wiring rack;

The high-temperature heating system is equipped with a cooling gas loop, and an independent cooling gas loop controls the flow of cooling gas. An independent cooling gas loop on the ground is connected to the cooling gas pipeline bracket of the hypergravity experimental cabin through the conductive slip ring of the centrifuge spindle. and exhaust pipe.

The present invention realizes a heating system that realizes directional solidification in a hypergravity environment, enabling crystal growth under hypergravity. The buoyancy convection is enhanced by increasing the gravity acceleration. When the buoyancy convection is enhanced to a certain extent, it is transformed into a laminar flow state. , that is, re-laminarization, which also suppresses irregular heat and mass convection. Forced convection of the liquid phase is caused during the accelerated rotation process, which greatly changes the heat and mass transfer process and causes significant changes in the interface morphology, resulting in a significant reduction in the width of the mushy zone. The rapid flow of the liquid phase causes a great increase in the temperature gradient in the liquid phase at the interface front, which is very conducive to the uniform mixing of liquid phase solutes and the growth of the planar interface of the material. The dendrite growth morphology changes significantly, from the original dendrites with obvious main axes. The crystals change into spike-shaped crystals with no obvious main axis, and the spike-shaped crystals have a fine microstructure.

The beneficial effects of the present invention are:

The invention can conduct high-temperature heating of material samples that require directional solidification and casting in a hypergravity environment, can realize directional solidification, casting and heating of materials under centrifugal load-thermal load coupling conditions, and can effectively solve the problem of material orientation under hypergravity and high-temperature test conditions. The problem of solidification, melting and casting heating has the advantages of simple structure, easy operation and high safety factor.

The invention cooperates with the hypergravity environment and can heat the directional solidification and casting samples of materials under high-speed rotation conditions, such as the orientation of high-temperature alloys and the growth of single crystals. It solves the key problem of directional solidification, casting and heating of materials under high-speed rotation, and fills the gap in the domestic technology industry. blank, simple equipment and easy operation. The invention is suitable for 1g-2000g hypergravity environment, and the heating temperature ranges from normal temperature to 10°C.

Description of the drawings

Figure 1 is the front view of the high-temperature heating system;

Figure 2 is a structural cross-sectional view of the crucible support base;

Figure 3 is a partial enlarged view of the structure of the heating furnace tube;

Figure 4 is a schematic structural diagram of the heating element;

Figure 5 is a schematic diagram of the electrical connection structure of the material directional solidification melting and casting system of the present invention.

Figure 6 is a schematic diagram of the directional solidification casting structure where the crucible and cooling system are installed according to the present invention.

Detailed ways

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the structures related to the present invention.

As shown in Figure 1, the high-temperature heating system is fixed in the hypergravity test chamber. The high-temperature heating system includes an upper furnace body, a middle furnace body, a lower furnace body, a mullite insulation layer 16, and an upper furnace body that are connected in sequence from top to bottom. Cavity outer body 17, lower heating chamber outer body 18, upper heating furnace tube 19, lower heating furnace tube 20, crucible support seat 21 and heating element 22; upper heat insulation cover 1, upper cavity shell 2, upper cavity middle shell 3. Upper cavity heat insulation layer 4, upper cavity lower fixed cover 5, middle heat insulation cover 6, middle cavity shell 7, middle cavity middle shell 8, middle cavity heat insulation layer 9, middle cavity lower fixation The cover 10, the lower insulation cover 11, the lower cavity shell 12, the lower cavity middle shell 13, the lower cavity insulation layer 14, and the lower cavity lower fixed cover 15 form a cylindrical high-temperature heating device composed of three furnace bodies. The shell of the system is mainly used to fix the high-temperature heating system in a hypergravity environment, and to protect the furnace body in a hypergravity environment, forming a high-temperature furnace as a whole.

The upper furnace body is mainly composed of the upper heat insulation cover 1, the upper cavity shell 2, the upper cavity middle shell 3, the upper cavity heat insulation layer 4, and the upper cavity lower fixed cover 5. The upper cavity shell 2, the upper cavity The middle shell 3 and the upper cavity heat insulation layer 4 are respectively installed from the outside to the inside to form a three-layer structure of the upper furnace. The upper heat insulation cover 1 and the lower fixed cover 5 of the upper cavity are respectively installed on the upper and lower ends of the three-layer structure of the upper furnace so that The three-layer structure of the upper furnace is fixedly connected, and the upper heat-insulating cover 1 is used to fix the three-layer structure of the upper furnace body and play the role of heat insulation; the upper cavity shell 2 and the upper cavity middle shell 3 and the upper cavity There is a gap between the middle shell 3 and the upper cavity heat insulation layer 4 as an air heat insulation layer. The air heat insulation layer plays the role of heat insulation and heat preservation to prevent heat loss in the furnace.

The middle furnace body is mainly composed of a middle heat insulation cover 6, a middle cavity shell 7, a middle cavity middle shell 8, a middle cavity heat insulation layer 9, and a middle cavity lower fixed cover 10. The middle cavity shell 7, the middle cavity body The middle shell 8 and the middle cavity heat insulation layer 9 are respectively installed from the outside to the inside to form a three-layer structure of the middle furnace. The middle heat insulation cover 6 and the lower fixed cover 10 of the middle cavity are respectively installed on the upper and lower ends of the three-layer structure of the middle furnace. The three-layer structure of the middle furnace is fixedly connected, and the middle heat-insulating cover 6 is used to fix the three-layer structure of the middle furnace body and play a role in heat insulation. conduction downward; there is a gap between the middle cavity shell 7 and the middle cavity shell 8 as well as between the middle cavity shell 8 and the middle cavity heat insulation layer 9 as an air heat insulation layer. It plays the role of heat insulation to prevent heat loss in the furnace; the lower fixed cover 5 of the upper cavity of the upper furnace body and the middle heat insulating cover 6 of the middle furnace body are fixedly connected, and the lower fixed cover 5 of the upper cavity and the middle heat insulating cover are fixedly connected. 6 connections are used to connect the upper furnace body and the middle furnace body.

The lower furnace body is mainly composed of a lower heat insulation cover 11, a lower cavity shell 12, a lower cavity middle shell 13, a lower cavity heat insulation layer 14, and a lower cavity lower fixed cover 15. The lower cavity shell 12, the lower cavity The middle shell 13 and the lower cavity heat insulation layer 14 are respectively installed from the outside to the inside to form a three-layer structure of the lower furnace. The lower heat insulation cover 11 and the lower fixed cover 15 of the lower cavity are respectively installed on the upper and lower ends of the three-layer structure of the lower furnace so that The three-layer structure of the lower furnace is fixedly connected, and the lower heat-insulating cover 11 is used to fix the three-layer structure of the lower furnace body and play the role of heat insulation. The conduction is downward, and the lower fixed cover 15 of the lower cavity is used to fix the high-temperature heating system at the bottom of the hypergravity test device. There is a gap between the lower cavity shell 12 and the lower cavity middle shell 13 and between the lower cavity middle shell 13 and the lower cavity heat insulation layer 14 as an air heat insulation layer, and the air heat insulation layer plays the role of heat insulation. It functions to prevent heat loss in the furnace; the lower fixed cover 10 of the middle furnace body and the lower heat insulating cover 11 of the lower furnace body are fixedly connected. The lower fixed cover 10 of the middle cavity and the lower heat insulating cover 11 are connected for connection. Middle furnace body and lower furnace body.

The entire furnace body is connected to the furnace through four places: upper heat insulation cover 1, upper cavity lower fixed cover 5, middle heat insulation cover 6, middle cavity lower fixed cover 10, lower heat insulation cover 11 and lower cavity lower fixed cover 15 The furnace body is strengthened to improve the rigidity and strength of the entire furnace body in a hypergravity environment and prevent the furnace body from deformation and damage during operation. The lower fixed cover 5 of the upper cavity and the middle heat-insulating cover 6, and the lower fixed cover 10 and the lower heat-insulating cover 11 of the middle cavity are connected by high-strength bolts to facilitate installation and maintenance.

As shown in Figure 2, the crucible support seat 21 is placed at the bottom of the lower cavity insulation layer 14 of the lower furnace body. The heating chamber is placed on the crucible support seat 21. The crucible support seat 21 is placed on the bottom of the hypergravity test cabin. The crucible The support base 21 is used to support the weight of the entire furnace body and the compressive stress generated under the action of hypergravity, and at the same time insulates heat to prevent heat from being conducted to the bottom of the hypergravity test device through thermal conduction under hypergravity. The heating cavity includes an upper heating cavity outer body 17, a lower heating cavity outer body 18, an upper heating furnace tube 19 and a lower heating furnace tube 20. The upper heating chamber outer body 17 and the lower heating chamber outer body 18 are both sleeve structures. The heating chamber outer body 17 and the lower heating chamber outer body 18 are respectively located at the upper and lower coaxial fixed joints. The bottom end of the lower heating chamber outer body 18 is fixed on the edge of the crucible support base 21. The upper heating furnace tube 19 and the lower heating furnace tube 20 are respectively installed. In the upper heating chamber outer body 17 and the lower heating chamber outer body 18, the upper heating chamber outer body 17 and the lower heating chamber outer body 18 are installed in the upper cavity insulation layer 4 of the upper furnace body and the middle cavity insulation layer of the middle furnace body. A mullite insulation layer 16 is filled between the thermal layer 9 and the lower cavity insulation layer 14 of the lower furnace body.

As shown in Figure 3, the outer walls of the upper heating furnace tube 19 and the lower heating furnace tube 20 are both processed with spiral grooves 22-1, and the spiral grooves 22-1 are equipped with spiral heating elements 22, as shown in Figure 4 It shows that the spiral groove 22-1 can effectively fix the heating element to prevent it from sliding under super gravity. The heat generated by the heating element 22 is evenly radiated to the heating furnace tube composed of the upper heating furnace tube 19 and the lower heating furnace tube 20. The center of the heating furnace tube composed of the upper heating furnace tube 19 and the lower heating furnace tube 20 forms a high-temperature zone; the upper heating chamber outer body 17 is used to install the upper heating furnace tube 19, and the upper heating chamber outer body 17 and the upper heating furnace tube 19 are used to install the upper heating furnace tube 19. Heat the upper part of the device. The lower heating chamber outer body 18 is used to install the lower heating furnace tube 20, and the lower heating chamber outer body 18 and the lower heating furnace tube 20 are used to heat the lower part of the device.

The upper and lower annular end surfaces of the upper heating chamber outer body 17 and the lower heating chamber outer body 18 are provided with a plurality of through holes for connecting the upper heat insulating cover 1 along the circumference, and the shaft connector/rod connector passes through the upper heat insulating cover 1 It is set in the through-hole in the same axial direction of the upper heating chamber outer body 17 and the lower heating chamber outer body 18 .

The structural design of the heating furnace tube and the heating element 22 of the present invention can prevent the heating element 22 from falling off in a hypergravity environment, and the heating effect can be adjusted by adjusting the pitch of the spiral groove at different positions.

As shown in Figure 2, there is a ventilation pipe 21-1 inside the crucible support seat 21. The ventilation pipe 21-1 is used to introduce cooling gas for directional solidification. The upper end of the ventilation pipe 21-1 penetrates through the top surface of the crucible support seat 21 as an outlet. And connected to the inside of the lower heating furnace tube 20, the lower end of the ventilation pipe 21-1 penetrates through the bottom of the crucible support seat 21 and serves as an entrance, connected to the space between the crucible support seat 21 and the lower cavity insulation layer 14,

As shown in Figure 6, a crucible and a cooling system are installed on the crucible support seat 21 inside the upper heating furnace tube 19 and the lower heating furnace tube 20. The cooling gas of the directional solidification test is passed into the bottom of the crucible through the ventilation pipe 21-1. The bottom of the crucible is cooled to form a temperature gradient along the direction of supergravity for directional solidification, and by regulating the incoming flow rate of the cooling gas and the temperature generated by the heating element 22, the distribution of the temperature gradient along the direction of supergravity is controlled.

During the working process, the heating element 22 generates heat, which heats the upper heating furnace tube 19 and the lower heating furnace tube 20 through radiation, forming a high-temperature zone in the center of the heating furnace tube, and changes the pitch of the spiral groove 22-1 at different heights. The heating element 22 at a height position at the distance between the heating furnace tubes cooperates with the temperature and flow rate of the cooling gas introduced into the ventilation pipe 21-1 of the crucible support base 21 to start cooling from the bottom of the crucible, forming a temperature gradient along the direction of supergravity.

The upper heating furnace tube 19 and the lower heating furnace tube 20 are made of ceramics with high strength and low thermal conductivity.

The specific implementation of the present invention also requires the selection of the heating element 22, the spiral groove pitch of the high-strength furnace tube 17, and the material type of the high-strength furnace tube 17.

Selection of the heating element 22: The maximum temperature allowed for different heating elements 22 and the requirements for the use environment are different. The type of the heating element 22 needs to be determined based on the specific usage conditions of the device (maximum operating temperature, vacuum environment and hypergravity environment). . Such as iron-chromium-aluminum electric heating alloy wire and platinum wire, etc.

The spiral groove pitch of the upper heating furnace tube 19 and the lower heating furnace tube 20 is: the heating element 22 is easily pulled up, deformed, or even broken under conditions of hypergravity. In addition to the layout design of the heating element 22, it is also necessary to consider a series of changes caused by the heating element 22, such as preventing the heating element 22 from breaking when it deforms and moves severely under hypergravity conditions, thus affecting the overall operation of the equipment.

Material types of the upper heating furnace tube 19 and the lower heating furnace tube 20: The material types of the upper heating furnace tube 19 and the lower heating furnace tube 20 are determined according to the type of the heating element 22 and the operating temperature requirements. In order to prevent deformation caused by the self-weight of the upper heating furnace tube 19 and the lower heating furnace tube 20 under excessive gravity, the furnace body of the high-temperature heating device is designed as a three-layer split type, with each layer having an individually reinforced insulation layer.

The high-temperature heating system is placed in the hypergravity environment of the centrifuge. The hypergravity test chamber is a test chamber for directional solidification of materials in a hypergravity environment and is placed in the hanging basket of a centrifuge.

As shown in Figure 5, the hypergravity experimental cabin is also equipped with a load-bearing frame, a signal collector and a wiring frame, and the material samples to be directional solidified are installed in the upper heating furnace tube 19 and the lower heating furnace tube 20 of the high-temperature heating system. It is equipped with a temperature sensor, which is connected to the signal collector. The wires output by the signal collector are connected to the weak signal conductive slip ring through the wiring frame, and then connected to the ground measurement and control center. The high-temperature heating system is equipped with an independent circuit for strong current and a strong current circuit. The electric independent circuit controls the heating elements 22 at different heights inside for high-temperature heating. A strong electric independent circuit on the ground is connected to the wiring frame of the hypergravity experimental cabin through the centrifuge spindle conductive slip ring; the high-temperature heating system is equipped with a cooling gas Loop, an independent cooling gas loop controls the incoming cooling gas flow, and connects an independent cooling gas loop on the ground to the cooling gas pipeline bracket and exhaust pipe of the hypergravity experimental cabin through the conductive slip ring of the centrifuge spindle.

In the specific implementation, an independent temperature-controlled temperature extension wire that controls the high-temperature heating device is connected to the signal collector. The signal collector converts the received temperature signal from an analog signal to a digital signal; the digital signal passes through the wiring frame and The signal slip ring is connected and then connected to the ground measurement and control center.

The furnace temperature is controlled by a temperature sensor fixed or welded on the sample to be tested through a temperature controller and measurement and control system.

When the device of the present invention is installed and used, the lower fixed cover 15 of the lower cavity is first fixed to the bottom of the hypergravity test device through bolts, the crucible support seat 21 is installed on the lower fixed cover 15 of the lower cavity, the lower cavity shell 12, the lower cavity The middle shell 13 and the lower cavity heat insulation layer 14 are connected to the lower cavity lower fixed cover 15 through bolts. The lower heat insulation cover 11 is connected to the middle cavity lower fixed cover 10 through bolts. The middle shell 8 and the middle cavity body The heat insulation layer 9 and the lower fixed cover 10 of the middle cavity are connected to the lower fixed cover 10 of the middle cavity through bolts, and then connected to the lower fixed cover 5 of the upper cavity and the middle heat insulation cover 6 through bolts.

The mullite insulation layer 16 is directly placed between the ceramic heating furnace tubes 19 and 20 and the lower cavity insulation layer 14 , the middle cavity insulation layer 9 , and the upper cavity insulation layer 4 . The mullite insulation layer 16 can both play a buffering role and insulate heat.

The high-temperature heating system is reusable and only needs to be replaced by suitable heating elements 2 and heating furnace tubes 19 and 20 to meet different experimental requirements. It has the advantages of simple structure and high safety factor.

The working process of mechanical property testing of the device of the present invention is as follows:

The first step: Place the hypergravity experimental cabin in the hanging basket of the centrifuge, place a high-temperature heating device in the hypergravity experimental cabin, and melt the sample through the crucible installed in the heating device;

Step 3: Connect the wires of the temperature measuring thermocouple arranged around the crucible to the signal collector. The signal collector will receive the temperature analog signal and convert the analog signal into a digital signal;

Step 4: A strong electric independent circuit is connected to the upper heating furnace tube 19 and the lower heating furnace tube 20 respectively to form a high temperature zone in the heating area;

Step 5: Install a tachometer on the rotating shaft of the centrifuge. Connect the tachometer signal line installed on the rotating shaft of the centrifuge to the weak signal conductive slip ring. Use a thermocouple on the heating device to control the real-time temperature and heating rate of the high-temperature furnace. Use a tachometer to control the speed of the centrifuge, and use the following formula to calculate the centrifugal stress F at the center of the crucible during directional solidification:

F＝m·a＝m·R(2πN/60) ²

Among them, m is the mass of the melt in the crucible; a is the centrifugal acceleration, and the calculation formula is a=R(2πN/60) ² , R is the effective distance from the center of the crucible to the axis of the centrifuge shaft; N is the rotation speed of the centrifuge.

The present invention can independently control the heating temperature of the high-temperature heating device through a thermocouple, and the cooling air volume introduced into the bottom of the crucible through the ventilation pipe 21-1 to cool the bottom of the crucible to form a temperature gradient along the direction of supergravity. By regulating the inlet flow rate and temperature, the temperature gradient is regulated.

Claims (6)

1. A high-temperature heating system for directional solidification and casting of materials in a hypergravity environment, which is characterized by: The high-temperature heating system is fixed in the hypergravity experimental cabin. The high-temperature heating system includes an upper furnace body, a middle furnace body, a lower furnace body and a mullite insulation layer (16) arranged and connected in sequence from top to bottom. Upper heating chamber outer body (17), lower heating chamber outer body (18), upper heating furnace tube (19), lower heating furnace tube (20), crucible support seat (21) and heating element (22); upper furnace body It is mainly composed of upper heat insulation cover (1), upper cavity shell (2), upper cavity middle shell (3), upper cavity heat insulation layer (4), and upper cavity lower fixed cover (5). The outer shell (2) of the body, the middle shell of the upper cavity (3), and the heat insulation layer of the upper cavity (4) are installed from the outside to the inside to form a three-layer structure of the upper furnace. The upper heat insulation cover (1) and the bottom of the upper cavity are fixed. The covers (5) are respectively installed on the upper and lower ends of the three-layer structure of the upper furnace so that the three-layer structure of the upper furnace is fixedly connected, between the upper cavity shell (2) and the upper cavity middle shell (3) and between the upper cavity middle shell ( There is a gap between 3) and the upper cavity heat insulation layer (4) as the air heat insulation layer; the middle furnace body is mainly composed of the middle heat insulation cover (6), the middle cavity shell (7), the middle cavity middle shell ( 8), the middle cavity heat insulation layer (9), the middle cavity lower fixed cover (10), the middle cavity shell (7), the middle cavity middle shell (8), the middle cavity heat insulation layer (9) They are installed from the outside to the inside to form a three-layer structure of the middle furnace. The middle heat insulation cover (6) and the lower fixed cover (10) of the middle cavity are respectively installed on the upper and lower ends of the three-layer structure of the middle furnace so that the three-layer structure of the middle furnace is fixedly connected. , there is a gap between the middle cavity shell (7) and the middle cavity shell (8) and between the middle cavity shell (8) and the middle cavity heat insulation layer (9) as an air heat insulation layer; upper The lower fixed cover (5) of the upper cavity of the furnace body is fixedly connected to the middle heat insulation cover (6) of the middle furnace body; the lower furnace body is mainly composed of a lower heat insulation cover (11), a lower cavity shell (12), The lower cavity middle shell (13), the lower cavity heat insulation layer (14), and the lower cavity lower fixed cover (15) are composed of the lower cavity outer shell (12), the lower cavity middle shell (13), and the lower cavity. The heat insulation layer (14) is installed from the outside to the inside to form a three-layer structure of the lower furnace. The lower heat insulation cover (11) and the lower fixed cover (15) of the lower cavity are respectively installed on the upper and lower ends of the three-layer structure of the lower furnace so that the lower furnace can The three-layer structure of the furnace is fixedly connected. There are gaps between the lower cavity shell (12) and the lower cavity middle shell (13) and between the lower cavity middle shell (13) and the lower cavity heat insulation layer (14). Air heat insulation layer; fixed connection between the lower fixed cover (10) of the middle cavity of the middle furnace body and the lower heat insulation cover (11) of the lower furnace body; The crucible support base (21) is placed at the bottom of the lower cavity insulation layer (14) of the lower furnace body, and the heating cavity is placed on the crucible support base (21). The heating cavity includes an upper heating cavity outer body (17) and a lower heating cavity body. The outer body of the heating chamber (18), the upper heating furnace tube (19) and the lower heating furnace tube (20). The outer body of the upper heating chamber (17) and the lower heating chamber outer body (18) are all sleeve structures. The upper heating chamber The outer body (17) and the lower heating cavity outer body (18) are respectively located at the upper and lower coaxial fixed joints. The upper heating furnace tube (19) and the lower heating furnace tube (20) are respectively set on the upper heating chamber outer body (17) and the lower heating chamber outer body (18). In the heating cavity outer body (18), the upper heating cavity outer body (17) and the lower heating cavity outer body (18) are insulated by the upper cavity heat insulation layer (4) of the upper furnace body and the middle cavity heat insulation layer of the middle furnace body. The layer (9) and the lower cavity insulation layer (14) of the lower furnace body are filled with a mullite insulation layer (16); the outer walls of the upper heating furnace tube (19) and the lower heating furnace tube (20) are processed There is a spiral groove (22-1). The spiral groove (22-1) is equipped with a spiral heating element (22). The heat generated by the heating element (22) radiates evenly to the upper heating furnace tube (19) and The heating furnace tube composed of the lower heating furnace tube (20) forms a high-temperature zone in the center of the heating furnace tube; there is a ventilation pipe (21-1) inside the crucible support seat (21), and the ventilation pipe (21-1) is used for directional solidification The cooling gas is introduced, the upper end of the ventilation pipe (21-1) runs through the top surface of the crucible support seat (21) as an outlet and is connected to the inside of the lower heating furnace tube (20), and the lower end of the ventilation pipe (21-1) runs through the crucible support The bottom of the seat (21) serves as the entrance. 2. A high-temperature heating system for directional solidification, melting and casting of materials in a hypergravity environment according to claim 1, characterized in that: the crucible supports inside the upper heating furnace tube (19) and the lower heating furnace tube (20) A crucible and a cooling system are installed on the seat (21). The cooling gas of the directional solidification test is introduced into the bottom of the crucible through the ventilation pipe (21-1). By cooling the bottom of the crucible, a temperature gradient along the direction of supergravity is formed and oriented. Solidification, and by regulating the incoming flow rate of the cooling gas and the temperature generated by the heating element (22), the temperature gradient distribution along the direction of supergravity is regulated. 3. A high-temperature heating system for directional solidification, melting and casting of materials in a hypergravity environment according to claim 1, characterized in that: during the working process, the heating element (22) generates heat and heats the upper heating furnace tube (19) and The lower heating furnace tube (20) forms a high-temperature zone in the center of the heating furnace tube. By changing the pitch of the spiral groove (22-1) at different heights, the spacing between the heating elements (22) at different heights is changed. According to the temperature and flow rate of the cooling gas introduced into the ventilation pipe (21-1) of the crucible support seat (21), cooling starts from the bottom of the crucible, forming a temperature gradient along the direction of supergravity. 4. A high-temperature heating system for directional solidification and melting and casting of materials in a hypergravity environment according to claim 1, characterized in that: the upper heating furnace tube (19) and the lower heating furnace tube (20) are made of high-strength, Made of ceramic with low thermal conductivity. 5. A high-temperature heating system for directional solidification, melting and casting of materials in a hypergravity environment according to claim 1, characterized in that: the high-temperature heating system is placed in a hypergravity environment of a centrifuge. 6. A high-temperature heating system for directional solidification and casting of materials in a hypergravity environment according to claim 1, characterized in that: a load-bearing frame, a signal collector and a wiring frame are also installed in the hypergravity experimental cabin. The material sample to be directional solidified is installed in the upper heating furnace tube (19) and the lower heating furnace tube (20) of the high-temperature heating system, and is provided with a temperature sensor. The temperature sensor is connected to a signal collector, and the wires output by the signal collector are routed through The frame is connected to the weak signal conductive slip ring, and then connected to the ground measurement and control center; The high-temperature heating system is equipped with a strong-current independent circuit. A strong-current independent circuit controls the internal heating elements (22) at different heights for high-temperature heating. A strong-current independent circuit on the ground is connected to the hypergravity experiment through the conductive slip ring of the centrifuge spindle. Cabin wiring rack; The high-temperature heating system is equipped with an independent cooling gas loop. An independent cooling gas loop controls the incoming cooling gas flow. An independent cooling gas loop on the ground is connected to the cooling gas pipeline bracket of the hypergravity experimental cabin through the conductive slip ring of the centrifuge spindle. and exhaust pipe.