CN113351844A - Method for precisely forming large-scale complex cavity titanium alloy casting - Google Patents

Method for precisely forming large-scale complex cavity titanium alloy casting Download PDF

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Publication number
CN113351844A
CN113351844A CN202010150224.6A CN202010150224A CN113351844A CN 113351844 A CN113351844 A CN 113351844A CN 202010150224 A CN202010150224 A CN 202010150224A CN 113351844 A CN113351844 A CN 113351844A
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casting
titanium alloy
shell
core
powder
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Inventor
赵军
史昆
刘时兵
刘鸿羽
王彦鹏
宁兆生
倪嘉
金磊
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Shenyang Research Institute of Foundry Co Ltd
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Shenyang Research Institute of Foundry Co Ltd
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Priority to CN202010150224.6A priority Critical patent/CN113351844A/en
Priority to PCT/CN2020/000059 priority patent/WO2021174375A1/en
Publication of CN113351844A publication Critical patent/CN113351844A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D13/00—Centrifugal casting; Casting by using centrifugal force
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/04—Use of lost patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/10—Cores; Manufacture or installation of cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/12—Treating moulds or cores, e.g. drying, hardening
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D13/00—Centrifugal casting; Casting by using centrifugal force
    • B22D13/10—Accessories for centrifugal casting apparatus, e.g. moulds, linings therefor, means for feeding molten metal, cleansing moulds, removing castings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D13/00—Centrifugal casting; Casting by using centrifugal force
    • B22D13/10—Accessories for centrifugal casting apparatus, e.g. moulds, linings therefor, means for feeding molten metal, cleansing moulds, removing castings
    • B22D13/101—Moulds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D13/00—Centrifugal casting; Casting by using centrifugal force
    • B22D13/10—Accessories for centrifugal casting apparatus, e.g. moulds, linings therefor, means for feeding molten metal, cleansing moulds, removing castings
    • B22D13/101—Moulds
    • B22D13/104—Cores

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mold Materials And Core Materials (AREA)

Abstract

The invention discloses a precise forming method of a large complex cavity titanium alloy casting, which adopts a precision casting composite coating core and a graphite casting mold to prepare the large complex cavity titanium alloy casting, the composite coating core and the graphite casting mold are degassed and then assembled into the casting mold, a consumable electrode is put into a vacuum consumable electrode skull furnace for smelting, titanium alloy liquid is cast into the casting mold by adopting a titanium alloy centrifugal casting process, and the complex cavity titanium alloy casting is obtained after centrifugation. The titanium alloy casting cast by the process improves the dimensional precision, the internal quality and the surface quality of the casting, greatly reduces the rejection rate of the casting, reduces the casting cost of the casting, shortens the production cycle of the casting, and has good economic benefit and social benefit.

Description

Method for precisely forming large-scale complex cavity titanium alloy casting
Technical Field
The invention relates to a casting method, in particular to a precise forming method of a titanium alloy casting with high pressure bearing, large size, complex cavity and thin wall.
Background
With the rapid development of industries such as aviation, aerospace, ships, petrochemical industry, mining and the like, the demand of some high-pressure-bearing, large-scale, complex and thin-wall titanium alloy castings in the field of rocket engine preparation is increasing. The product is mainly formed by casting, and the prior titanium alloy casting technology mainly adopts the processes of rare earth ceramic pattern investment casting, machining graphite pattern casting and the like.
Aiming at the precise forming of titanium alloy castings with high bearing capacity, large size, complex cavities and thin walls, the casting process of the mechanically-added graphite casting mold is adopted for casting, a large amount of graphite is consumed for processing the casting mold, the graphite casting mold has very strong chilling effect on titanium alloy liquid due to the high heat conductivity of the graphite, the defects of cold shut, cracks and the like can be generated on the contact part of metal liquid and the graphite surface due to the fast cooling speed, meanwhile, the graphite core is generally used for forming complex cavities of the castings, the cavity parts are difficult to polish and process by using tools due to the abnormal and complex structure, the defects are very difficult to remove, the quality of the casting surface is often unqualified, the castings are scrapped, the rejection rate of the castings is high, the production cycle of the castings is greatly influenced, and the production efficiency is low. If a rare earth ceramic investment precision casting technology is adopted, although higher casting dimensional accuracy and better surface quality can be obtained, for titanium alloy castings with high bearing pressure, large and complex cavities and thin walls, a large wax pressing machine is needed for preparing a wax mould, the cost of the mould for preparing the wax mould is very high, the shell making process has multiple working procedures, the wax mould is easy to soften and deform in the shell making process, the dimensional accuracy cannot be effectively guaranteed, a surface layer is easy to fall off, and high-density slag inclusion is easy to generate in the castings, so that the quality of the castings is unqualified. Therefore, no matter which casting process has the technical problems of complex casting mold manufacturing, high casting rejection rate, high production cost, high labor intensity, long production period and the like, and a new casting process method is urgently needed to solve the technical bottleneck problem of precise forming of high-pressure-bearing large-scale complex-cavity and thin-wall titanium alloy castings.
At present, large-scale, complex cavity channel and thin-wall titanium alloy casting products generally have the defects of cold shut, air holes and the like, can not meet the requirements of higher-quality rocket engine parts in the future, and a method for forming a high-internal-quality and high-surface-quality titanium alloy complex structural member is urgently needed to be developed, so that the product quality is improved, the quality cost is reduced, and the production efficiency is improved.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a high-pressure-bearing large-scale complex-cavity and thin-wall titanium alloy casting precision forming method, which utilizes the chilling action of a graphite casting mold and the high surface quality, high dimensional precision and high deformability of a precision casting composite coating core to obtain the high-pressure-bearing large-scale complex-cavity and thin-wall titanium alloy casting with qualified required quality.
In order to realize the technical problem, the invention is obtained by the following technical scheme:
a large complex cavity titanium alloy casting precision forming method comprises the steps of preparing a large complex cavity titanium alloy casting by adopting a precision casting composite coating core and a graphite casting mold, assembling the composite coating core and the graphite casting mold into the casting mold after degassing, putting a consumable electrode into a vacuum consumable electrode skull furnace for smelting, casting titanium alloy liquid into the casting mold by adopting a titanium alloy centrifugal casting process, and obtaining the complex cavity titanium alloy casting after centrifugation.
The precision casting composite shell-coated core comprises the following specific steps:
(1) adding the surface layer refractory powder into the surface layer binder, uniformly mixing and stirring for 1-3 hours to prepare a surface layer coating; coating the coating on a wax mold, scattering surface sand, and drying for 8-12 hours at 18-22 ℃ and with the humidity of 45-55%; repeating the operation for 2-3 times to form a surface layer shell; the mass ratio of the surface layer refractory powder to the surface layer binder is 2-3.5: 1. the refractory powder of the surface layer is Y with the grain diameter of 40-80 mu m2O3And ZrO having a particle diameter of 40 to 80 μm2Mixture of, wherein ZrO230-50 wt% of powder and the balance of Y2O3And (3) pulverizing. The surface layer sand isZrO having a particle size of 80 to 150 μm2And (4) sand. The surface layer binder is nano-alumina dispersion liquid, and the concentration of the dispersion liquid is 8-12 wt%.
(2) Adding the back layer powder into the back layer binder, uniformly mixing, scattering back layer sand, and drying for 8-12 hours at the temperature of 18-22 ℃ and the humidity of 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell; the mass ratio of the back layer powder to the back layer binder is 2-3: 1. the back layer adhesive is a silica sol adhesive solution with the concentration of 15-20 wt%. The back layer sand is Al with the grain diameter of 80-150 mu m2O3And (4) sand. The back layer powder is Al with the granularity of 40-80 mu m2O3Powder and ZrO with grain size of 40-80 mu m2In which Al is2O3The mass fraction of the powder is 80-90 wt%, and the balance is ZrO2。
(3) Dewaxing the coated shell; the dewaxing adopts an infrared dewaxing process, and the temperature of a heating shell ranges from 300 ℃ to 350 ℃.
(4) And (4) putting the shell obtained in the step (3) into a box-type resistance furnace for roasting, cooling, and discharging at room temperature to obtain the composite shell-coated core. The roasting condition in the step (4) is as follows: and heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, and preserving heat for 3-4 h.
The degassing process of the graphite casting mold and the composite coating mold core specifically comprises the following steps: putting the graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace; the fine casting composite shell-coated core is put into a box-type resistance furnace, heated to 350-400 ℃, kept warm for 2-3 h, and cooled to 100-150 ℃ along with the furnace.
The smelting specifically comprises the following steps: the consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃; the casting specifically comprises the following steps: casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 rpm.
And (3) grouping: and assembling the graphite casting mold and the precision casting composite coating mold core which are subjected to degassing treatment into a casting mold according to a casting mold assembly diagram.
The invention has the advantages that:
the titanium alloy casting cast by the process aims at the high-pressure-bearing large-scale complex-cavity and thin-wall titanium alloy precise casting, improves the dimensional precision, the internal quality and the surface quality of the casting, greatly reduces the rejection rate of the casting, reduces the casting cost of the casting, shortens the production cycle of the casting, and has good economic benefit and social benefit.
Detailed Description
The present invention is further described with reference to the following specific examples, but the scope of the present invention is not limited by the examples, and if one skilled in the art makes some insubstantial modifications and adaptations to the present invention based on the above disclosure, the present invention still falls within the scope of the present invention.
The invention provides a high-pressure-bearing large-scale complex cavity and thin-wall titanium alloy casting precision forming method, which utilizes the chilling action of a graphite casting mold and the high surface quality, high dimensional precision and high deformability of a precision casting composite coating core to obtain the high-pressure-bearing large-scale complex cavity and thin-wall titanium alloy casting with qualified required quality.
The technical scheme is as follows:
a high-pressure-bearing, large-scale, complex-cavity and thin-wall titanium alloy casting precise forming method comprises the following process steps:
firstly, preparing a precision casting composite shell coating core:
1. preparing a surface layer material:
the surface powder is prepared from Y2O3、ZrO2The mixture is prepared by mixing the following components in percentage by mass: ZrO of grain size of 40-80 mu m230-50 wt% of powder and the balance of 40-80 mu m Y2O3And (3) pulverizing.
The surface layer sand is made of ZrO 80-150 mu m2Sand.
The surface layer adhesive is nano alumina dispersion liquid with the concentration of 8-12 wt%.
2. Preparing a back layer material:
the back layer powder consists of Al with granularity of 40-80 microns2O380-90 wt% of powder and the balance of 40-80 mu m ZrO2Mixing the powders uniformly.
The back layer sand material is made of Al with the thickness of 80-150 mu m2O3And (4) forming.
The back layer adhesive is silica sol solution with the concentration of 15-20 wt%.
3. Core wax pattern preparation
And designing a core wax mold according to the casting cavity, wherein the wax mold is prepared from medium-temperature wax, and a wax pressing machine is used for preparing a qualified wax mold.
3. Core and shell making process for precision casting composite coated shell
The first step is as follows: adding the prepared surface layer refractory powder into a nano alumina dispersion liquid surface layer binder with the concentration of 8-12 wt%, uniformly mixing, wherein the powder-liquid mass ratio is 2: 1-3.5: 1, and uniformly stirring for 1-3 hours to prepare a surface layer coating; the coating is coated and hung on a wax mould, and 80-150 mu m ZrO is adopted for sanding2Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 45-55%; repeating the operation for 2-3 times to form a surface layer shell with a certain thickness;
the second step is that: adding the prepared back layer powder into 15-20 wt% of silica sol binder, uniformly mixing, controlling the powder-liquid mass ratio to be 2: 1-3: 1, and sanding by adopting 80-150 mu m Al2O3Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell with a certain thickness;
the third step: dewaxing the coated shell, and heating the shell to 300-350 ℃ by adopting an infrared dewaxing process to completely remove wax;
the fourth step: and (4) putting the shell with the wax removed completely into a box-type resistance furnace for roasting. Firstly, heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, preserving heat for 3-4 h, and finally cooling the core along with the furnace to room temperature and discharging the core out of the furnace.
4. Surface treatment of the precision casting composite shell coating core:
and (4) polishing and removing the redundant substances on the surface of the precision casting composite shell-coated core by using a sand paper polishing method.
Secondly, preparing a graphite casting mould
And (4) preparing the graphite casting mold by a machining method according to the requirements of design drawings.
Third, graphite casting mold and composite coating mold core degassing
1. Graphite casting mould degassing process
And (3) putting the prepared graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace to obtain the graphite casting mold.
2. Degassing process for precision casting composite coating shell core
And putting the prepared precision casting composite shell-coated core into a box-type resistance furnace, heating to 350-400 ℃, preserving heat for 2-3 h, and cooling to 100-150 ℃ along with the furnace to obtain the core.
Four, group type
And assembling the graphite casting mold and the precision casting composite coating mold core which are subjected to degassing treatment into a casting mold according to a casting mold assembly diagram.
Fifthly, smelting and casting
The consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃. And then casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 revolutions per minute, so as to obtain the titanium alloy casting mould.
Example 1
The precise forming process of large complicated cavity titanium alloy casting includes the following steps:
firstly, preparing a precision casting composite shell coating core:
1. preparing a surface layer material:
the surface powder is prepared from Y2O3、ZrO2The mixture is prepared by mixing the following components in percentage by mass: ZrO of grain size of 40-80 mu m230 wt% of powder and the balance of 40-80 mu m Y2O3And (3) pulverizing.
The surface layer sand is made of ZrO 80-150 mu m2Sand.
The surface layer adhesive is nano alumina dispersion liquid with the concentration of 8 wt%.
2. Preparing a back layer material:
the back layer powder consists of Al with granularity of 40-80 microns2O380 wt% of powder and the balance of 40-80 mu m ZrO2Mixing the powders uniformly.
The back layer sand material is made of Al with the thickness of 80-150 mu m2O3And (4) forming.
The back layer adhesive is silica sol solution with the concentration of 15 wt%.
3. Core wax pattern preparation
And designing a core wax mold according to the casting cavity, wherein the wax mold is prepared from medium-temperature wax, and a wax pressing machine is used for preparing a qualified wax mold.
3. Core and shell making process for precision casting composite coated shell
The first step is as follows: adding the prepared surface layer refractory powder into a nano-alumina dispersion liquid surface layer binder with the concentration of 8 wt%, uniformly mixing, wherein the powder-liquid mass ratio is 2: 1, and uniformly stirring for 1-3 hours to prepare a surface layer coating; the coating is coated and hung on a wax mould, and 80-150 mu m ZrO is adopted for sanding2Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 45-55%; repeating the operation for 2 times to form a surface layer shell with a certain thickness;
the second step is that: adding the prepared back layer powder into 15 wt% silica sol binder, mixing, controlling the powder-liquid mass ratio at 2: 1, and sanding with 80-150 μm Al2O3Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell with a certain thickness;
the third step: dewaxing the coated shell, and heating the shell to 300-350 ℃ by adopting an infrared dewaxing process to completely remove wax;
the fourth step: and (4) putting the shell with the wax removed completely into a box-type resistance furnace for roasting. Firstly, heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, preserving heat for 3-4 h, and finally cooling the core along with the furnace to room temperature and discharging the core out of the furnace.
4. Surface treatment of the precision casting composite shell coating core:
and (4) polishing and removing the redundant substances on the surface of the precision casting composite shell-coated core by using a sand paper polishing method.
Secondly, preparing a graphite casting mould
And (4) preparing the graphite casting mold by a machining method according to the requirements of design drawings.
Third, graphite casting mold and composite coating mold core degassing
1. Graphite casting mould degassing process
And (3) putting the prepared graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace to obtain the graphite casting mold.
2. Degassing process for precision casting composite coating shell core
And putting the prepared precision casting composite shell-coated core into a box-type resistance furnace, heating to 350-400 ℃, preserving heat for 2-3 h, and cooling to 100-150 ℃ along with the furnace to obtain the core.
Four, group type
And assembling the graphite casting mold and the precision casting composite coating mold core which are subjected to degassing treatment into a casting mold according to a casting mold assembly diagram.
Fifthly, smelting and casting
The consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃. Then casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 r/minAnd (5) obtaining the product.
The practical application is as follows: the titanium alloy casting cast by the process has the surface roughness of a cavity reaching Ra5.0 mu m, is superior to the surface roughness of Ra12.5 mu m of the traditional graphite casting process, obviously improves the surface quality of the casting and has good economic and social benefits.
Example 2
Firstly, preparing a precision casting composite shell coating core:
1. preparing a surface layer material:
the surface powder is prepared from Y2O3、ZrO2The mixture is prepared by mixing the following components in percentage by mass: ZrO of grain size of 40-80 mu m240 wt% of powder and the balance of 40-80 mu m Y2O3And (3) pulverizing.
The surface layer sand is made of ZrO 80-150 mu m2Sand.
The surface layer adhesive is nano alumina dispersion liquid with the concentration of 10 wt%.
2. Preparing a back layer material:
the back layer powder consists of Al with granularity of 40-80 microns2O385 wt% of powder and the balance of 40-80 mu m ZrO2Mixing the powders uniformly.
The back layer sand material is made of Al with the thickness of 80-150 mu m2O3And (4) forming.
The back layer adhesive is silica sol solution with the concentration of 18 wt%.
3. Core wax pattern preparation
And designing a core wax mold according to the casting cavity, wherein the wax mold is prepared from medium-temperature wax, and a wax pressing machine is used for preparing a qualified wax mold.
3. Core and shell making process for precision casting composite coated shell
The first step is as follows: adding the prepared surface layer refractory powder into a nano-alumina dispersion liquid surface layer binder with the concentration of 10 wt%, uniformly mixing, wherein the powder-liquid mass ratio is 3: 1, and uniformly stirring for 1-3 hours to prepare a surface layer coating; the coating is coated and hung on a wax mould, and 80-150 mu m ZrO is adopted for sanding2Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 45-55%;repeating the operation for 2-3 times to form a surface layer shell with a certain thickness;
the second step is that: adding the prepared back layer powder into 18 wt% silica sol binder, mixing, controlling the powder-liquid mass ratio at 2.5: 1, and sanding with 80-150 μm Al2O3Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell with a certain thickness;
the third step: dewaxing the coated shell, and heating the shell to 300-350 ℃ by adopting an infrared dewaxing process to completely remove wax;
the fourth step: and (4) putting the shell with the wax removed completely into a box-type resistance furnace for roasting. Firstly, heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, preserving heat for 3-4 h, and finally cooling the core along with the furnace to room temperature and discharging the core out of the furnace.
4. Surface treatment of the precision casting composite shell coating core:
and (4) polishing and removing the redundant substances on the surface of the precision casting composite shell-coated core by using a sand paper polishing method.
Secondly, preparing a graphite casting mould
And (4) preparing the graphite casting mold by a machining method according to the requirements of design drawings.
Third, graphite casting mold and composite coating mold core degassing
1. Graphite casting mould degassing process
And (3) putting the prepared graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace to obtain the graphite casting mold.
2. Degassing process for precision casting composite coating shell core
And putting the prepared precision casting composite shell-coated core into a box-type resistance furnace, heating to 350-400 ℃, preserving heat for 2-3 h, and cooling to 100-150 ℃ along with the furnace to obtain the core.
Four, group type
And assembling the graphite casting mold and the precision casting composite coating mold core which are subjected to degassing treatment into a casting mold according to a casting mold assembly diagram.
Fifthly, smelting and casting
The consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃. And then casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 revolutions per minute, so as to obtain the titanium alloy casting mould.
The practical application is as follows: the titanium alloy casting cast by the process has the advantages that the size precision of a cavity can reach CT6 level, is obviously superior to CT7 level of the traditional graphite casting process, obviously improves the size precision of the cavity of the casting, and has good economic benefit and social benefit.
Example 3
Firstly, preparing a precision casting composite shell coating core:
1. preparing a surface layer material:
the surface powder is prepared from Y2O3、ZrO2The mixture is prepared by mixing the following components in percentage by mass: ZrO of grain size of 40-80 mu m250 wt% of powder and the balance of 40-80 mu m Y2O3And (3) pulverizing.
The surface layer sand is made of ZrO 80-150 mu m2Sand.
The surface layer adhesive is nano alumina dispersion liquid with the concentration of 12 wt%.
2. Preparing a back layer material:
the back layer powder consists of Al with granularity of 40-80 microns2O390 wt% of powder and the balance of 40-80 mu m ZrO2Mixing the powders uniformly.
The back layer sand material is made of Al with the thickness of 80-150 mu m2O3And (4) forming.
The back layer adhesive is silica sol solution with the concentration of 20 wt%.
3. Core wax pattern preparation
And designing a core wax mold according to the casting cavity, wherein the wax mold is prepared from medium-temperature wax, and a wax pressing machine is used for preparing a qualified wax mold.
3. Core and shell making process for precision casting composite coated shell
The first step is as follows: adding the prepared surface layer refractory powder into a12 wt% nano-alumina dispersion liquid surface layer binder, uniformly mixing, wherein the mass ratio of the powder to the liquid is 3.5: 1, and uniformly stirring for 1-3 hours to prepare a surface layer coating; the coating is coated and hung on a wax mould, and 80-150 mu m ZrO is adopted for sanding2Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 45-55%; repeating the operation for 2-3 times to form a surface layer shell with a certain thickness;
the second step is that: adding the prepared back layer powder into 20 wt% silica sol binder, mixing, controlling the powder-liquid mass ratio at 3: 1, and sanding with 80-150 μm Al2O3Sand, wherein the drying time is controlled to be 8-12 hours, the environmental temperature is controlled to be 18-22 ℃, and the humidity is controlled to be 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell with a certain thickness;
the third step: dewaxing the coated shell, and heating the shell to 300-350 ℃ by adopting an infrared dewaxing process to completely remove wax;
the fourth step: and (4) putting the shell with the wax removed completely into a box-type resistance furnace for roasting. Firstly, heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, preserving heat for 3-4 h, and finally cooling the core along with the furnace to room temperature and discharging the core out of the furnace.
4. Surface treatment of the precision casting composite shell coating core:
and (4) polishing and removing the redundant substances on the surface of the precision casting composite shell-coated core by using a sand paper polishing method.
Secondly, preparing a graphite casting mould
And (4) preparing the graphite casting mold by a machining method according to the requirements of design drawings.
Third, graphite casting mold and composite coating mold core degassing
1. Graphite casting mould degassing process
And (3) putting the prepared graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace to obtain the graphite casting mold.
2. Degassing process for precision casting composite coating shell core
And putting the prepared precision casting composite shell-coated core into a box-type resistance furnace, heating to 350-400 ℃, preserving heat for 2-3 h, and cooling to 100-150 ℃ along with the furnace to obtain the core.
Four, group type
And assembling the graphite casting mold and the precision casting composite coating mold core which are subjected to degassing treatment into a casting mold according to a casting mold assembly diagram.
Fifthly, smelting and casting
The consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃. And then casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 revolutions per minute, so as to obtain the titanium alloy casting mould.
The practical application is as follows: the titanium alloy casting cast by the process has the mechanical property tensile strength of 895MPa, which is obviously higher than the tensile strength of 845MPa of the traditional investment precision casting process, obviously improves the mechanical property of the casting, and has good economic and social benefits.

Claims (10)

1. A large complex cavity titanium alloy casting precision forming method is characterized in that a precision casting composite coating core and a graphite casting mold are adopted to prepare a large complex cavity titanium alloy casting, the composite coating core and the graphite casting mold are degassed and then assembled into a casting mold, a consumable electrode is placed into a vacuum consumable electrode skull furnace for smelting, titanium alloy liquid is cast into the casting mold by adopting a titanium alloy centrifugal casting process, and the complex cavity titanium alloy casting is obtained after centrifugation.
2. The method for precisely forming the large-scale complex-cavity titanium alloy casting according to claim 1, wherein the precise casting of the composite coated core comprises the following specific steps:
(1) adding the surface layer refractory powder into the surface layer binder, uniformly mixing and stirring for 1-3 hours to prepare a surface layer coating; coating the coating on a wax mold, scattering surface sand, and drying for 8-12 hours at 18-22 ℃ and with the humidity of 45-55%; repeating the operation for 2-3 times to form a surface layer shell;
(2) adding the back layer powder into the back layer binder, uniformly mixing, scattering back layer sand, and drying for 8-12 hours at the temperature of 18-22 ℃ and the humidity of 35-50%; repeating the operation for 4-6 times to form a reinforcing layer shell;
(3) dewaxing the coated shell;
(4) and (4) putting the shell obtained in the step (3) into a box-type resistance furnace for roasting, cooling, and discharging at room temperature to obtain the composite shell-coated core.
3. The method for precisely forming the large-scale complex-cavity titanium alloy casting according to claim 2, wherein the mass ratio of the surface layer refractory powder to the surface layer binder is 2-3.5: 1; the mass ratio of the back layer powder to the back layer binder is 2-3: 1.
4. the method for precisely forming the large-scale titanium alloy casting with the complicated cavity according to claim 2, wherein the refractory powder of the surface layer is Y with the grain diameter of 40-80 μm2O3And ZrO having a particle diameter of 40 to 80 μm2Mixture of, wherein ZrO230-50 wt% of powder and the balance of Y2O3Pulverizing; the back layer powder is Al with the granularity of 40-80 mu m2O3Powder and ZrO with grain size of 40-80 mu m2In which Al is2O3The mass fraction of the powder is 80-90 wt%, and the balance is ZrO2。
5. The method for precisely forming the large-scale titanium alloy casting with the complex cavity according to claim 2, wherein the surface layer adhesive is nano-alumina dispersion liquid, and the concentration of the dispersion liquid is 8-12 wt%; the back layer adhesive is a silica sol adhesive solution with the concentration of 15-20 wt%.
6. The method for precisely forming the large-sized complex-cavity titanium alloy casting according to claim 2, wherein the surface sand is ZrO having a grain size of 80 to 150 μm2Sand; the back layer sand is Al with the grain diameter of 80-150 mu m2O3And (4) sand.
7. The method for precisely forming the large-scale complex-channel titanium alloy casting according to claim 2, wherein the dewaxing adopts an infrared dewaxing process, and the temperature of a heating shell is 300-350 ℃.
8. The large-scale complex-channel titanium alloy casting precision forming method according to claim 2, wherein the step (4) comprises the following steps: and heating the shell to 600 ℃, preserving heat for 2-3 h, then continuously heating the core to 950-1100 ℃, and preserving heat for 3-4 h.
9. The method for precisely forming the large-scale complex-cavity titanium alloy casting according to claim 1, wherein the degassing process specifically comprises the following steps: putting the graphite casting mold into a vacuum degassing furnace, heating to 850-900 ℃, preserving heat for 3h, and cooling to room temperature along with the furnace; the fine casting composite shell-coated core is put into a box-type resistance furnace, heated to 350-400 ℃, kept warm for 2-3 h, and cooled to 100-150 ℃ along with the furnace.
10. The method for precisely forming the large-scale complex-cavity titanium alloy casting according to claim 1, wherein the smelting specifically comprises: the consumable electrode is made of Ti-6Al-4VELI alloy ingot, the consumable electrode is placed in a vacuum consumable electrode skull furnace, the gap between the consumable electrode and the inner wall of the crucible is 30-100mm, a vacuum pump is started, and the consumable electrode is pumped until the vacuum degree is less than or equal to 10-1After Pa, smelting at the voltage of 38-40V and the current of 12000-18000A; the cooling water pressure is 0.5MPa, the temperature of the crucible inlet water is 19 ℃, and the temperature of the crucible outlet water is 38 ℃;
the casting specifically comprises the following steps: and casting titanium alloy liquid into the casting mould by adopting a titanium alloy centrifugal casting process, wherein the centrifugal rotating speed is 300 r/min.
CN202010150224.6A 2020-03-06 2020-03-06 Method for precisely forming large-scale complex cavity titanium alloy casting Pending CN113351844A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114406196A (en) * 2021-12-31 2022-04-29 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped inner cavity
CN114425598A (en) * 2021-12-31 2022-05-03 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped gap holes

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114700465A (en) * 2022-03-02 2022-07-05 中国电建集团郑州泵业有限公司 Roasting method for final-stage guide vane investment casting formwork of double-casing pump
CN115283645B (en) * 2022-06-20 2024-01-19 中国航发哈尔滨东安发动机有限公司 Preparation and application methods of magnesium alloy low-pressure investment casting ceramic shell
CN116555603B (en) * 2023-04-19 2023-11-24 西部超导材料科技股份有限公司 Smelting method of TC17 titanium alloy cast ingot

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101733383A (en) * 2010-01-28 2010-06-16 沈阳铸造研究所 Precision casting method for graphite mould-ceramic core titanium alloy
CN102019360A (en) * 2010-12-30 2011-04-20 沈阳黎明航空发动机(集团)有限责任公司 Rapid moulding method of hollow support plate core
CN104550755A (en) * 2013-10-29 2015-04-29 青岛齐力铸钢有限公司 Precision casting method for graphite mould-ceramic core titanium alloy
CN107282857A (en) * 2017-05-12 2017-10-24 上海大学 MgO‑SrZrO3Composite shell, using and preparation method thereof
CN109967714A (en) * 2019-05-07 2019-07-05 上海工程技术大学 Composite centrifugal casting mold for annular titanium alloy part

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6755239B2 (en) * 2001-06-11 2004-06-29 Santoku America, Inc. Centrifugal casting of titanium alloys with improved surface quality, structural integrity and mechanical properties in isotropic graphite molds under vacuum
CN107052242A (en) * 2016-10-31 2017-08-18 中国航空工业集团公司北京航空材料研究院 The combined type casting method that a kind of diecasting and model casting are combined
CN107159869B (en) * 2017-04-19 2018-12-21 沈阳铸造研究所 A kind of preparation method of the fired mold precision casting type shell for easy oxidation metal

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101733383A (en) * 2010-01-28 2010-06-16 沈阳铸造研究所 Precision casting method for graphite mould-ceramic core titanium alloy
CN102019360A (en) * 2010-12-30 2011-04-20 沈阳黎明航空发动机(集团)有限责任公司 Rapid moulding method of hollow support plate core
CN104550755A (en) * 2013-10-29 2015-04-29 青岛齐力铸钢有限公司 Precision casting method for graphite mould-ceramic core titanium alloy
CN107282857A (en) * 2017-05-12 2017-10-24 上海大学 MgO‑SrZrO3Composite shell, using and preparation method thereof
CN109967714A (en) * 2019-05-07 2019-07-05 上海工程技术大学 Composite centrifugal casting mold for annular titanium alloy part

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
周彦邦, 航空工业出版社 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114406196A (en) * 2021-12-31 2022-04-29 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped inner cavity
CN114425598A (en) * 2021-12-31 2022-05-03 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped gap holes
CN114425598B (en) * 2021-12-31 2023-10-27 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped slit holes
CN114406196B (en) * 2021-12-31 2023-12-15 北京航空材料研究院股份有限公司 Preparation method of titanium and titanium alloy casting containing special-shaped inner cavity

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