CN2583113Y - Single crystal high temperature alloy electric field unidirectional solidification equipment - Google Patents

Abstract

The utility model relates to the solidification technology of a single crystal superalloy, specifically a single crystal superalloy electric field directional solidification equipment, which has a shell, a heating device, a sample clamping mechanism and a DC electric field generating device, and the clamping mechanism is placed in the shell Below the body, there are two clamping rods on the bracket. One end of the two clamping rods is respectively connected to the rotating shaft on the bracket, and the other end is connected by a fastener. Spring, the other end of the tension spring is fixed on the bracket, the lower end of the sample passes through the hole opened in the middle of the bottom of the shell and placed between the two clamping rods, and the bracket has a through hole through which the sample passes; The DC electric field generating device is a closed loop formed by a programmable functional module connected in series between one end of the sample and one pole of the regulated power supply, and the other end is connected to the other pole of the regulated power supply through a clamping rod. The utility model avoids the generation of miscellaneous crystals in the directional solidification process, refines the solidification structure of the single crystal superalloy, and is beneficial to rapid quenching.

Description

A single crystal superalloy electric field directional solidification equipment

technical field

The utility model relates to the solidification technology of a single crystal superalloy, in particular to an electric field directional solidification device for a single crystal superalloy.

Background technique

Single crystal superalloys have superior high-temperature creep properties and low-cycle thermal fatigue properties, and are the preferred superalloy materials for aeroengine blades. However, the solidification rate of single crystal superalloys is low, and the solidification structure is coarse; at the same time, due to the high degree of alloying, solute segregation is very easy to occur, which has an adverse effect on the structure and properties of the alloy, which limits the potential of single crystal superalloys. Minimizing the solidification structure of single crystal superalloys and reducing solidification segregation are the goals pursued by the field of materials research. The existing research results show that the electric field can refine the metal solidification structure, improve the γ′ phase morphology, reduce segregation and microporosity, and help improve the performance of single crystal superalloys. Compared with ordinary directionally solidified superalloys, single crystal superalloys have the advantage of eliminating grain boundaries and improving high-temperature performance. How to avoid the generation of miscellaneous crystals during directional solidification is a problem that needs to be carefully considered and solved in experiments and production. In ordinary argon-protected directional solidification equipment, due to the argon flow through the gap between the test tube and the heat insulation baffle, the excess heat is lost, causing the radial temperature gradient of the directional solidification solid-liquid interface to increase, which is not conducive to the DC electric field. After the DC electric field, how to quench the sample is also a problem that needs to be solved.

Utility model content

The purpose of the utility model is to provide a single crystal superalloy electric field directional solidification equipment which avoids the generation of miscellaneous crystals, refines the metal solidification structure and facilitates rapid quenching during the directional solidification process.

The technical solution of the utility model is to have a housing, a heating device, a sample clamping mechanism and a DC electric field generating device. The clamping mechanism is placed under the housing and consists of two clamping rods on the bracket. One end of the two clamping rods is respectively connected to the rotating shaft on the bracket, which can rotate around the rotating shaft, and the other end is connected by a fastener, and tension springs are respectively installed on the outer surfaces thereof, and the other ends of the tension spring are fixed on the bracket. The lower end of the sample passes through the hole in the middle of the bottom of the shell and is placed between two clamping rods. The bracket has a through hole for the sample to pass through; A programmable function module is connected in series between one pole of the piezoelectric power supply, and the other end is connected to the other pole of the voltage-stabilizing power supply through a clamping rod to form a closed loop, and the current of the voltage-stabilizing power supply is 0-60A;

There are corresponding grooves on the opposite sides of the two clamping rods to match the clamped sample; cooling water pipes are respectively provided on the outer sides of the two clamping rods; the fasteners are fastening screws;

The heating device is composed of an induction heater and an induction body. The bottom of the induction body is provided with a heat insulation baffle, and insulation cotton is provided between the top and the outer periphery of the induction body and the inner wall of the housing. The distance between the induction body and the inner wall of the housing is The thermal insulation cotton in between has air holes; the heat insulation baffle is a cylinder with a cylindrical hole in the middle, and radial ventilation grooves at the bottom; the thermal insulation cotton is Al ₂ O ₃ thermal insulation cotton; the shell It is a quartz glass cover; the induction body is a graphite induction body.

The utility model has the following characteristics:

1. The utility model introduces a DC electric field, so that an electric field can be applied during directional solidification, and various electric field application modes can be realized through a programmable program module, which can refine the metal solidification structure, improve the γ′ phase morphology, and reduce segregation and microporosity , which is conducive to improving the performance of single crystal superalloys.

2. The argon flow route adopted in the utility model realizes that the argon flow passing through the directional solidified solid-liquid interface is very small, ensuring that the radial temperature gradient of the directional solidified solid-liquid interface is reduced, reducing the possibility of miscellaneous crystals, and the solidified part remains monolithic. crystal state.

3. The utility model adopts a water-cooled clamping mechanism that can be opened quickly to quickly take away the heat at the bottom of the sample, and can be used as a pole for introducing a DC electric field at the same time. The clamping mechanism can be opened quickly, and the solid-liquid interface of the sample can be quenched during solidification. Fast quenching.

4. The heating temperature of the experimental equipment for electric field directional solidification of the utility model can reach 1700°C, and the temperature gradient when the single crystal superalloy is solidified is 200°C/cm.

5. In the utility model, the electromagnetic induction effect of the induction heating magnetic field on the liquid metal is shielded, so as to avoid the stirring effect of the induction heating magnetic field on the liquid metal.

6. Due to the good protective effect of argon gas in the utility model, the superalloy sample is slightly oxidized, and the graphite induction body is very little burned.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is the electrical schematic diagram of the utility model heating device.

Fig. 3 is a schematic diagram of the formation of the argon protective gas curtain of the present invention.

Fig. 4 is a structural schematic diagram of the clamping mechanism of the present invention.

Fig. 5 is a schematic diagram of the principle of the DC electric field generating device of the present invention.

Detailed ways

As shown in Figure 1, the structure of the electric field directional solidification equipment for a single crystal superalloy includes three parts: a heating device 4, a clamping mechanism 7 and a DC electric field generating device. This is described in detail below.

The heating device 4 uses an IGBT super-audio power supply to generate single-phase alternating current, which is sent to the induction heater 41 after being stepped down by the transformer. The induction heater 41 heats the graphite induction body 42, and the graphite induction body 42 heats the sample 3 by radiation. The principle is shown in Figure 2.

The graphite induction body 42 is surrounded by high-purity Al ₂ O ₃ insulation cotton 11 for insulation. The Al ₂ O ₃ insulation cotton 11 has a refractoriness higher than 1700°C and has a good insulation effect. After the heating furnace works at 1550°C for two hours, the quartz glass The temperature of cover (shell) 2 is still lower than 400°C. Foam refractory bricks are selected to make the heat insulation baffle. The heat insulation baffle 5 is made into a cylindrical shape with a cylindrical hole in the middle and a radial ventilation groove at the bottom; The gap between the Al ₂ O ₃ insulation cotton 11 above the body 42 and the Al ₂ O ₃ crucible 10 is compacted to minimize the passage of argon gas, and the Al ₂ O ₃ insulation cotton 11 between the induction body 42 and the inner wall of the quartz glass cover 2 is tied There are ventilation holes, so that the argon gas from the argon gas inlet 1 mainly flows through the radial ventilation grooves at the bottom of the inner wall of the quartz glass cover and the heat insulation baffle plate 5 made of foam refractory bricks; The outer diameter of the ₂ O ₃ crucible is slightly larger, so that the Al ₂ O ₃ crucible can pass through the bottom of the quartz glass cover 2, and the argon gas can flow out from the argon gas outlet 6 in the pores of the two, so as to realize the sealing protection of the argon gas.

Figure 3 is a schematic diagram of the formation of the argon protective gas curtain in the equipment. The argon flow at the solidification interface is very small, which keeps the solidification interface level and reduces the possibility of miscellaneous crystals during solidification.

The quartz glass cover 2 is divided into three sections. The upper section of the glass cover has a hole for introducing wires. The hole diameter is slightly larger than the diameter of the wire. During the directional solidification, the wires can fall freely. There is an argon inlet 1, and the middle glass cover can only be opened when replacing the graphite induction body 42 and heat insulation baffle 5; the graphite induction body 42, heat insulation baffle 5 and thermal insulation cotton are all placed in the lower section of the quartz glass cover 2 , Sample 3 passed through the hole at the bottom of the lower section of the quartz glass cover.

According to the long-term statistical results, the current is 0-60A/cm ² . On the electric field directional solidification equipment of single crystal superalloy, after directional solidification of DD3 single crystal superalloy, more than 90% of the samples still maintain the single crystal state, while in conventional equipment On the surface, more than 30% of the samples appeared miscellaneous crystals.

The air in the quartz glass cover is fully expelled, the single crystal superalloy is completely in the argon atmosphere, the burning loss is very small, the oxidation of the superalloy melt by the air is significantly reduced, and the directionally solidified graphite induction body has very little burning loss.

When the argon gas mainly flows through the inner wall of the quartz glass cover 2 and the bottom of the heat insulation baffle 5, the heat taken away by the argon gas is reduced, and the power required by the IGBT super audio power supply is reduced, which has a certain energy-saving effect.

As shown in Figure 4, the clamping mechanism structure schematic diagram, the clamping mechanism 7 is placed under the housing 2, and is composed of two clamping rods 75 arranged on the bracket 74, and the bottom of the sample 3 passes through the middle of the bottom of the housing 2 The hole provided in the position is placed between two clamping rods 75, and the lower end of the sample 3 is fixed by the clamping rod 75 at the arc groove slightly larger than its radius, and the clamping rod 75 can surround the rotating shaft 76 on the plane of the bracket 74. Rotate upward, under the action of the clamping force of the fastener (fastening screw) 72, the test rod 2 is firmly clamped; one end of the two clamping rods 75 is connected with the rotating shaft 76 on the bracket 74 respectively, and the other end passes through Fasteners (fastening screws) 72 are connected, and tension springs 73 are respectively installed on their outer surfaces, and the other end of the tension springs 73 is fixed to the bracket 74, and the clamping rod is made of copper alloy with excellent thermal conductivity , the outside is welded with a cooling water pipe 71 (copper pipe), under the action of cooling water, the heat at the bottom of the sample 3 is quickly taken away, so that the front edge of the solid-liquid interface of the directional solidified sample has a higher temperature gradient, and the heating temperature is 1550 ℃, the temperature gradient at the front of the directional solidification solid-liquid interface of DD3 superalloy reaches 200 ℃/cm, when the clamping screw 72 is opened, the clamping rod 75 is quickly opened under the force of the tension spring 73, and the sample 3 passes through the bracket The through hole on the 74 falls into the quenching mechanism.

Figure 5 is a schematic diagram of the DC electric field generating device. During the directional solidification process, the middle part of the sample 3 is in a liquid state, and the two ends remain solid. The top of the sample 3 is connected with a molybdenum wire, and the positive electrode of the regulated power supply 9 is connected to the programmable function module 8. The lower end of the sample 3 is connected to the negative pole of the stabilized power supply 9 through the clamping rod 75 to form a closed loop. The current of the stabilized power supply is continuously adjustable within the range of 0-60A. The programmable function module 8 is the prior art. : The AF-10M2-A programmable function module produced by Taiwan Array Electric Co., Ltd. can realize various timing switch functions.

Claims (6)

1. single crystal super alloy electric-field directional solidification equipment, has housing (2), heating unit (4), it is characterized in that also comprising sample clamping mechanism (7) and DC electric field generating unit, described clamping device (7) places housing (2) below, being provided with two supporting rods (75) by carriage (74) constitutes, described two supporting rods (75) one ends are connected with rotating shaft (76) on the carriage (74) respectively, the other end connects by fastening piece (72), and its outer side is separately installed with tensioning spring (73), tensioning spring (73) the other end is fixed in carriage (74), sample (3) lower end is passed the hole that mid-way, housing (2) bottom has and is placed between two supporting rods (75), and described carriage (74) has the through hole that sample (3) passes; Described DC electric field generating unit is to be in series with programmable functions module (8) between the utmost point of sample (3) one ends and voltage stabilized source (9), loop line of the other end another formation that extremely links to each other by supporting rod (75) and voltage stabilized source (9).

2. according to the described single crystal super alloy electric-field directional solidification of claim 1 equipment, it is characterized in that the opposite flank of described two supporting rods (75) has corresponding groove, match with the sample (3) of clamping.

3. according to claim 1 or 2 described single crystal super alloy electric-field directional solidification equipment, it is characterized in that described two supporting rods (75) outside is respectively equipped with water-cooled tube (71).

4. according to the described single crystal super alloy electric-field directional solidification of claim 1 equipment, it is characterized in that described heating unit (4) is made of induction heater (41) and inductor (42), inductor (42) bottom is provided with thermal baffle (5), the top of inductor (42) and outer periphery are provided with insulating cotton (11) between housing (2) inner side-wall, the insulating cotton (11) between inductor (42) and housing (2) inner side-wall is pricked ventilating pit; Described thermal baffle (5) is a right cylinder, and the centre has cylindrical hole, and radial ventilation groove is left in the bottom.

5. according to the described single crystal super alloy electric-field directional solidification of claim 4 equipment, it is characterized in that described insulating cotton (11) is Al ₂O ₃Insulating cotton; Described housing (2) is a quartz glass cover; Described inductor (42) is the graphite inductor.

6. according to the described single crystal super alloy electric-field directional solidification of claim 1 equipment, it is characterized in that described voltage stabilized source (9) electric current is 0～60A.

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