A high-throughput method for the production of [111] oriented single crystal high temperature alloys

Abstract

The present application relates to single crystal alloy preparation technical field, especially to a kind of [111] orientation single crystal high-temperature alloy high-throughput preparation method.The preparation method of the present application includes: providing the included angle relationship between different orientation seed crystal and casting direction;From bottom to top, different orientation seed crystal, taper amplifier wax mould, casting wax mould and riser are sequentially arranged to obtain different combination wax mould, and the direction of the casting wax mould is set according to the included angle relationship between the different orientation seed crystal and the casting direction;After the outer part of the different combination wax mould is coated with refractory coating, it is defrased to obtain different casting mould shell;After the different casting mould shell is assembled around the center ring, the molten high-temperature alloy mother liquor is poured into the casting mould shell, directional solidification casting is carried out, and the [111] orientation single crystal high-temperature alloy is obtained.The preparation method can ensure that [111] orientation single crystal high-temperature alloy is grown from different orientation seed crystal at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of single crystal alloy preparation, and particularly relates to a high-throughput preparation method of

[111] oriented single crystal superalloy. BACKGROUND

[0002] Nickel-based single crystal superalloy is widely used in turbine blade materials of advanced aero-engine and industrial gas turbine due to its excellent high-temperature strength and high-temperature creep resistance. Higher temperature resistance is one of the eternal themes of material science, and is the frontier of high-temperature structural material science. Single crystal alloy materials for aero-engine turbine blades challenge the limit of material science in terms of high temperature resistance, high load, environmental resistance and long service life. In the research process, the seed crystal method can accurately control the three-dimensional orientation of the crystal when growing single crystal turbine blades. With the increase of the inlet temperature of the aero-engine turbine and the increase of the preparation cost of high-generation nickel-based single crystal superalloy, accurate control of the crystal orientation of the blade can improve the service life of the single crystal turbine blade and reduce the replacement frequency of the single crystal blade in the aero-engine, which is very important. Therefore, the seed crystal method will play an important role in the industrial production of single crystal turbine blades.

[0003] Recently, through the study of the anisotropy of single crystal superalloy on the performance, it is found that the single crystal material with

[111] orientation as the main axis or the main force direction is expected to solve the performance problem of 1500℃ alloy. The directional solidification process of this kind of material has certain difficulties, the reason is that the preferential orientation of the casting dendrite stem and dendrite wall growth determined by thermodynamics is

[001] orientation, and the angle with

[111] crystal orientation is as high as 53°, it is difficult to ensure that the micro dendrite stem and the macro casting main shaft are in the directional solidification temperature gradient direction at the same time. High-index orientation seed crystal method can effectively improve the

[111] oriented single crystal alloy dendritic structure and casting hole, and can provide new possibilities for the design and preparation of high-temperature structural materials of high-temperature single crystal alloy and other high-temperature structural materials.

[0004] At present,

[111] oriented single crystal superalloy is prepared by high-index seed crystal, and the main process is as follows: 1) high-index seed crystal preparation of single crystal superalloy; 2) single crystal test rod or casting shell design and shell preparation; 3) single crystal prepared by high-index seed crystal directional solidification casting. Limited by single casting, if it is necessary to compare the casting results of different orientation seeds, multiple experiments need to be carried out, which cannot make the single crystal casting growth environment consistent for comparison, and the production cycle is lengthened, which is not time-saving; multiple mold assembly is also required, which also increases the experimental cost, and is not conducive to production and experiment.

[0005] With the rapid development of material genetic engineering technology, modern material research and development gradually enters the "data-driven fourth paradigm of scientific research". Among them, "material high-throughput experiment" is to complete the preparation and characterization of a large number of samples in a short time. Its core idea is to change the sequential iteration method used in traditional material research to parallel processing, so as to cause the qualitative change of material research efficiency from quantity change. The development and application of high-throughput experiment method can obtain rich experimental data in a short time, which can not only enrich the material database for the material simulation calculation, but also provide experimental verification for the results of material simulation calculation, so as to optimize and modify the calculation model. More importantly, high-throughput experiment can quickly provide valuable research results, directly accelerating the screening and optimization of materials. Therefore, the present application intends to use high-throughput preparation method in single crystal casting production, so as to make the single crystal grow from different orientation seeds through shell design, so as to facilitate the uniform growth environment, improve the casting efficiency, reduce the cost, and improve the efficiency, systematicness and consistency of the experiment. SUMMARY

[0006] The purpose of the present application is to provide a high-throughput preparation method of

[111] oriented single crystal superalloy, which can ensure the growth of

[111] oriented single crystal superalloy from different orientation seeds at the same time.

[0007] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0008] The present application provides a preparation method of

[111] oriented single crystal superalloy, comprising the following steps:

[0009] The angle relationship between the different orientation seeds and the casting direction is provided.

[0010] Different orientation seeds, tapered amplifier wax molds, casting wax molds and risers are sequentially arranged from bottom to top to assemble different combination wax molds, and the direction of the casting wax mold is set according to the angle relationship between the different orientation seeds and the casting direction.

[0011] After the outer part of the different combination wax molds is coated with a refractory coating, the wax is removed to obtain different casting molds.

[0012] After the different casting molds are assembled through connecting pieces, the molten superalloy mother liquor is poured into the casting molds for directional solidification casting to obtain the

[111] oriented single crystal superalloy.

[0013] Preferably, when the seed orientation is

[001] , the angle between the casting direction and the seed orientation is 54.7°.

[0014] when the seed crystal orientation is

[110] , the angle between the casting direction and the seed crystal orientation is 35.3°;

[0015] when the seed crystal orientation is

[221] , the angle between the casting direction and the seed crystal orientation is 15.8°;

[0016] when the seed crystal orientation is

[112] , the angle between the casting direction and the seed crystal orientation is 19.5°;

[0017] when the seed crystal orientation is

[113] , the angle between the casting direction and the seed crystal orientation is 29.5°;

[0018] when the seed crystal orientation is

[111] , the angle between the casting direction and the seed crystal orientation is 0°.

[0019] Preferably, the material of the refractory coating comprises white corundum and silica sol;

[0020] The thickness of the refractory coating is 5-20mm, and the number of layers is 5-6.

[0021] Preferably, the dewaxing method is water vapor dewaxing;

[0022] The temperature of the water vapor dewaxing is 500℃, and the time is 8-12min.

[0023] Preferably, after the dewaxing, the method further comprises baking;

[0024] The temperature of the baking is 1050℃, and the time is 10h.

[0025] Preferably, during the baking, the method further comprises adding ammonium chloride.

[0026] Preferably, after obtaining the casting mold shell, the method further comprises detecting the obtained casting mold shell;

[0027] The detection comprises internal particle detection and shell crack and weak link detection.

[0028] Preferably, the internal particle detection process comprises: using a dry cleaning machine to blow air into the inner cavity of the casting mold shell, while using a dust collection system to adsorb impurities onto a filter screen, and detecting the area of particulate matter on the filter screen.

[0029] The shell crack and weak link detection process comprises: using methylene blue solution as a pseudo-developing agent, and pouring it into the cavity for 1min; if there is any leakage, the casting mold shell is repaired or scrapped.

[0030] Preferably, the temperature of the directional solidification casting is 1540℃, the holding time is 5-30min, and the pulling rate is 4.5mm / min.

[0031] The application provides a preparation method of

[111] oriented single crystal superalloy, comprising the following steps: providing an included angle relationship between different orientation seed crystals and a casting direction; sequentially arranging the seed crystals with different orientations, a tapered amplifier wax mold, a casting wax mold and a riser from bottom to top to obtain different combined wax molds, and setting the direction of the casting wax mold according to the included angle relationship between the different orientation seed crystals and the casting direction; coating the outer part of the different combined wax molds with a refractory coating, and then defatting to obtain different casting mold shells; after assembling the different casting mold shells through connecting pieces, pouring a molten superalloy mother liquor into the casting mold shells to perform directional solidification casting, and obtaining the

[111] oriented single crystal superalloy. The application uses multiple seed crystals with different orientations to complete casting production of single crystals in one experiment, and the method has high efficiency, systematicness and consistency; the preparation method makes the growth environment of seed crystals with different orientations consistent, and a batch of single crystals is obtained at the same time, which is convenient for subsequent single crystal performance testing and comparison; the preparation method belongs to a high-throughput preparation technology, multiple experiments are performed at the same time in a relatively short time, and the traditional "one by one" or "single step" research and development mode is replaced, so that the cost and experimental time are effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structure diagram of the combined wax mold of the application, wherein 1 is a seed crystal, 2 is an amplifier, 3 is a single crystal, 4 is a riser;

[0033] Figure 2 It is a physical map of the combined wax mold with a coating shell of the application;

[0034] Figure 3 It is a physical map of the casting mold shell of the application;

[0035] Figure 4 It is a physical map of the

[111] single crystal superalloy casting of the application;

[0036] Figure 5 It is an optical microscope map of the

[111] single crystal superalloy casting of Example 1;

[0037] Figure 6 It is a Laue spectrum map of the

[111] single crystal superalloy casting of Example 1. DETAILED DESCRIPTION

[0038] The application provides a preparation method of

[111] oriented single crystal superalloy, comprising the following steps:

[0039] Providing an included angle relationship between different orientation seed crystals and a casting direction;

[0040] Assembling the seed crystal, the taper amplifier wax mold, the casting wax mold and the riser in sequence from bottom to top to obtain different combined wax molds, and setting the direction of the casting wax mold according to the included angle relationship between the seed crystal with different orientations and the casting direction;

[0041] Coating the outer part of the different combined wax molds with a refractory coating, and then dewaxing to obtain different casting molds;

[0042] Assembling the different casting molds through the connecting piece, pouring the molten high-temperature alloy mother liquor into the casting molds, and then performing directional solidification casting to obtain the

[111] oriented single crystal high-temperature alloy.

[0043] In the present application, all the raw materials for preparation are commercially available products well known to those skilled in the art, unless otherwise specified.

[0044] In the present application, the included angle relationship between the seed crystal with different orientations and the casting direction is provided.

[0045] In the present application, when the seed crystal orientation is

[001] , the included angle between the casting direction and the seed crystal orientation is preferably 54.7°; when the seed crystal orientation is

[110] , the included angle between the casting direction and the seed crystal orientation is preferably 35.3°; when the seed crystal orientation is

[221] , the included angle between the casting direction and the seed crystal orientation is preferably 15.8°; when the seed crystal orientation is

[112] , the included angle between the casting direction and the seed crystal orientation is preferably 19.5°; when the seed crystal orientation is

[113] , the included angle between the casting direction and the seed crystal orientation is preferably 29.5°; and when the seed crystal orientation is

[111] , the included angle between the casting direction and the seed crystal orientation is preferably 0°.

[0046] The preparation method of the present application further comprises assembling the seed crystal, the taper amplifier wax mold, the casting wax mold and the riser in sequence from bottom to top to obtain different combined wax molds, and setting the direction of the casting wax mold according to the included angle relationship between the seed crystal with different orientations and the casting direction.

[0047] The present application does not have any special limitation on the assembly process, and the process well known to those skilled in the art can be used.

[0048] After the assembly is completed, the present application further preferably comprises cleaning and drying in sequence; the present application does not have any special limitation on the cleaning process, and the process well known to those skilled in the art can be used to ensure that the oil on the surface of the combined wax mold is removed. In the present application, the cleaning function is to increase the coating property of the wax mold surface; the present application does not have any special limitation on the drying process, and the blow-drying process well known to those skilled in the art can be used.

[0049] After obtaining the combined wax mold, the present application coats the outside of the different combined wax mold with a refractory coating, and then dewaxes to obtain different casting mold shells.

[0050] In the present application, the material of the refractory coating preferably comprises white corundum and silica sol; the thickness of the refractory coating is preferably 5-20 mm, more preferably 8-16 mm, and most preferably 10-13 mm; and the number of layers is preferably 5-6 layers. In the present application, after coating with each layer of the refractory coating, drying is preferably included, and the drying time is preferably ≥12 h.

[0051] In the present application, the material and thickness of the refractory coating affect the air permeability, thermal shock stability and shell strength of the shell. The material and thickness of the refractory coating defined in the above technical solution can ensure that the shell has excellent air permeability, thermal shock stability and shell strength.

[0052] In the present application, the dewaxing method is preferably water vapor dewaxing; the temperature of the water vapor dewaxing is preferably 500°C, and the time is preferably 8-12 min, and more preferably 9-10 min. In the present application, the process of water vapor dewaxing is preferably to place the combined wax mold after scraping the refractory coating into a dewaxing kettle, evaporate deionized water after heating, and then dewax with water vapor.

[0053] In the present application, the dewaxing is to melt and discharge the wax mold inside the combined wax mold, so before dewaxing, the riser of the combined wax mold needs to be cut open to ensure that the wax mold melts and is smoothly discharged. The present application does not have any special limitation on the process of cutting open, which can be performed using a process well known to those skilled in the art.

[0054] After the dewaxing is completed, the present application also preferably includes baking, and the temperature of the baking is preferably 1050°C; and the time is preferably 10 h.

[0055] In the present application, since there are residual substances in the shell after dewaxing, if they are not removed, they will affect the quality of the casting, and the baking can sufficiently remove the residual substances after dewaxing.

[0056] In the present application, the baking process also preferably includes adding ammonium chloride; the present application does not have any special limitation on the amount of ammonium chloride added, which can be added using an amount well known to those skilled in the art. In the present application, the ammonium chloride acts as a hardener and can strengthen the shell.

[0057] After the casting shell is obtained, the application also preferably comprises detecting the obtained casting shell; the detection preferably comprises internal particle detection and shell crack and weak link detection; the process of the internal particle detection preferably comprises: using a dry cleaning machine to blow air into the internal cavity of the casting shell, while using a dust collection system to adsorb impurities onto a filter screen, and detecting the particle area of the filter screen; the process of the shell crack and weak link detection preferably comprises: using a methylene blue solution as a pseudo-developing agent, pouring it into the cavity for 1 minute, and if there is any leakage, repairing or scrapping.

[0058] After different casting shells are obtained, the application assembles the different casting shells through connecting pieces, pours the molten high-temperature alloy mother liquor into the casting shells, performs directional solidification casting, and obtains the

[111] oriented single-crystal high-temperature alloy.

[0059] In the application, the assembly preferably takes the connecting piece as the center, and the different casting shells are placed around the center and assembled; the application does not have any special limitation on the process of the assembly, and a process well known to those skilled in the art can be used.

[0060] The application does not have any special limitation on the composition of the high-temperature alloy mother liquor, and a composition well known to those skilled in the art can be used.

[0061] In the application, the temperature of the directional solidification casting is preferably 1540°C; the holding time is preferably 5-30 minutes, more preferably 10-25 minutes, and most preferably 15-20 minutes; and the pulling rate is preferably 4.5 mm / min.

[0062] The high-throughput preparation method of the

[111] oriented single-crystal high-temperature alloy provided by the application will be described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the application.

[0063] Example 1

[0064] Shell assembly scheme design: The casting shells are placed around the center, and the structure of each casting shell is sequentially arranged from top to bottom as follows: a riser, a single crystal, an amplifier, and a seed crystal (as shown in Figure 1 The seed crystal and the orientation deviation angle of the grown single crystal (i.e., the casting direction) are as shown in Table 1, and the seed crystals in each casting are

[001] ,

[110] ,

[112] ,

[113] ,

[221] , and

[111] , respectively;

[0065] Table 1: Deviation angle of different orientation seed crystals and main shaft

[0066] Seed crystal orientation Angle of departure from principal axis 001 54.7 110 35.3 221 15.8 112 19.5 113 29.5 111 0

[0067] According to the above shell assembly scheme, the wax mold is combined: according toFigure 1 As shown in the structure, different oriented seeds, amplifier wax molds, single crystal casting wax molds and risers are assembled to obtain different combined wax molds respectively; grease on the surface of the combined wax mold is cleaned to increase the coatability of the surface of the combined wax mold, and finally the mold group is dried;

[0068] The surface of the combined wax mold is coated with white corundum powder and silica sol (thickness of 18 mm, 6 layers) in sequence, and after each layer is coated, drying is performed before coating the next layer to obtain a combined wax mold with a coating shell (as shown in Figure 2 );

[0069] The riser in the combined wax mold with a coating shell is cut open and placed in a dewaxing kettle, deionized water is heated (temperature of 500℃) and evaporated, and then water vapor dewaxing is performed, and after 10 min of heat preservation, the mold shell is obtained by roasting to remove residual substances in the mold shell, and the roasting temperature is 1050℃ and the time is 10 h;

[0070] The mixture (silica gel, aluminum powder and cement with a mass ratio of 1:1.5:1) is used to repair the cut-off riser, and the repair process is to apply the prepared mixture to the riser position, perform riser repair and sealing, and then dry the repair position to obtain a complete casting mold shell (as shown in Figure 3 );

[0071] The casting mold shell is detected: 1) a dry cleaning machine is used to blow air into the inner cavity of the shell, and a dust collection system is used to adsorb impurities onto the filter screen, and the particle area of the filter screen is detected; 2) shell crack and weak link detection: methylene blue solution is used as a developer and poured into the cavity for about 1 min, and if there is seepage, it indicates that the quality is not good enough and needs to be repaired or scrapped;

[0072] Directional solidification of single crystal: after melting the high-temperature alloy (specific type is IC21 alloy), the obtained molten liquid is poured into a mold shell with a temperature of 1540℃, heat preservation for 30 min, and directional extraction at a pulling rate of 4.5 mm / min to obtain a

[111] single crystal high-temperature alloy casting (as shown in Figure 4 );

[0073] Wherein Figure 5 is the optical microscope image of the

[111] single crystal high-temperature alloy casting, and from Figure 5 It can be seen that the single crystal dendrite arm angle is close to 60°, the dendrite arrangement is neat and regular, and it is very consistent with the

[111] oriented single crystal dendrite morphology.

[0074] Figure 6 is the Laue spectrum of the

[111] single crystal high-temperature alloy casting, and from Figure 6It can be seen that the single crystal pattern is similar to snowflakes, the included angle is about 60°, which is consistent with the

[111] orientation single crystal Laue pattern characteristics.

[0075] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a [111]-oriented single crystal high-temperature alloy, characterized in that: The following steps are involved: Provide the angle relationship between seeds of different orientations and the casting direction; From bottom to top, seed crystals with different orientations, tapered amplifier wax molds, casting wax molds, and risers are sequentially arranged and assembled to obtain different combined wax molds, and the directions of the casting wax molds are set according to the angles between the seed crystals with different orientations and the casting direction; After coating the exterior of the different combined wax molds with a refractory coating, dewaxing to obtain different casting mold shells; After assembling the different casting molds through connectors, the molten high-temperature alloy mother solution is poured into the casting molds to perform directional solidification casting to obtain the [111] oriented single crystal high-temperature alloy; When the seed crystal orientation is [001], the angle between the casting direction and the seed crystal orientation is 54.7°; When the seed crystal orientation is [110], the angle between the casting direction and the seed crystal orientation is 35.3°; When the seed crystal orientation is [221], the angle between the casting direction and the seed crystal orientation is 15.8°; When the seed crystal orientation is [112], the angle between the casting direction and the seed crystal orientation is 19.5°; When the seed crystal orientation is [113], the angle between the casting direction and the seed crystal orientation is 29.5°; When the seed crystal orientation is [111], the angle between the casting direction and the seed crystal orientation is 0°; The temperature of the directional solidification casting is 1540° C., the holding time is 30 min, and the pulling rate is 4.5 mm / min.

2. The preparation method according to claim 1, wherein The materials of the refractory coating include white corundum and silica sol; The thickness of the refractory coating is 5-20 mm, and the number of layers is 5-6.

3. The preparation method according to claim 1, wherein The dewaxing method is steam dewaxing; The steam dewaxing temperature is 500° C. and the time is 8 to 12 minutes.

4. The preparation method according to claim 1, wherein After the dewaxing is completed, the process further comprises roasting; The calcination temperature is 1050° C. and the calcination time is 10 h.

5. The preparation method according to claim 4, wherein The roasting process also includes adding ammonium chloride.

6. The preparation method according to claim 1, wherein After obtaining the casting mold, the method further includes testing the obtained casting mold; The inspection includes internal particle inspection and shell crack and weak link inspection.

7. The preparation method according to claim 6, wherein The internal particle detection process includes: using a dry cleaning machine to blow air into the inner cavity of the casting mold shell, and at the same time using a dust collection system to absorb impurities onto the filter screen, and detecting the particle area of ​​the filter screen; The process of detecting cracks and weak links in the shell includes: using methylene blue solution as a similar developer, pouring it into the cavity for 1 minute, and if there is leakage, repairing it or scrapping it.

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