CN115889702A - Casting method of high-temperature alloy hollow triplet high-pressure guide blade - Google Patents
Casting method of high-temperature alloy hollow triplet high-pressure guide blade Download PDFInfo
- Publication number
- CN115889702A CN115889702A CN202211355581.1A CN202211355581A CN115889702A CN 115889702 A CN115889702 A CN 115889702A CN 202211355581 A CN202211355581 A CN 202211355581A CN 115889702 A CN115889702 A CN 115889702A
- Authority
- CN
- China
- Prior art keywords
- pressure guide
- triplet
- oxide ceramic
- triplet high
- guide blade
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Turbine Rotor Nozzle Sealing (AREA)
Abstract
The patent relates to the technical field of investment precision casting, in particular to a casting method of a high-temperature alloy hollow triplet high-pressure guide blade, which comprises the following steps: s1: manufacturing a hollow triplet high-pressure guide blade mould; s2: pressing a triplet high-pressure guide blade model; s3: bonding the module; s4: manufacturing an oxide ceramic shell; s5: preheating an oxide ceramic shell; s6: pouring molten metal; s7: and taking out the hollow triplet high-pressure guide blade. Compared with the commonly used mode of firstly pressing monomer blades and then assembling, welding and splicing the monomer blades into the triplet blades, the triplet high-pressure guide blade model has the advantages of better model size consistency, smaller model deformation, higher production efficiency and lower cost, and solves the problems of metallurgical defects, size error and low percent of pass generated in the casting process of the high-temperature alloy hollow triplet high-pressure guide blade.
Description
Technical Field
The invention relates to the technical field of investment precision casting, in particular to a casting method of a high-temperature alloy hollow triplet high-pressure guide blade.
Background
The turbine guider of the aircraft engine has the function of converting partial heat energy of airflow into kinetic energy and enabling the kinetic energy to flow out in a certain direction to push the turbine to do work. The guide vane, especially the high-pressure guide vane, has very bad working conditions, is surrounded by high-temperature fuel gas except for large aerodynamic force and unstable pulsating load, and has high temperature, large cold and heat change, large temperature gradient inside the vane and easy occurrence of thermal fatigue cracks.
In order to improve the temperature bearing capacity of the high-pressure guide blade and facilitate assembly and replacement, the high-pressure guide blade is usually designed into a complex hollow two-connection body or three-connection body high-temperature alloy blade, the wall thickness difference is large, the thermal bonding is more, molten metal filling turbulence is easily generated in the casting pouring process, the cooling sequence is not easy to control, the shrinkage of each structure is inconsistent, and the like, so that the metallurgical quality and the size of the casting cannot meet the technical condition requirements, and the qualified rate is lower.
Disclosure of Invention
The invention aims to provide a casting method of a high-temperature alloy hollow triplet high-pressure guide blade, and aims to solve the problems of metallurgical defects, size over-tolerance and low percent of pass generated in the casting process of the high-temperature alloy hollow triplet high-pressure guide blade.
In order to achieve the above object, the basic scheme of the invention is as follows: a casting method of a high-temperature alloy hollow triplet high-pressure guide blade comprises the following steps:
s1: the method comprises the following steps of manufacturing a hollow triplet high-pressure guide blade mould, wherein the mould comprises a bottom plate, a side mould sliding block, a drawing block and an upper cover, wherein a core slot is formed in the side mould sliding block, the side mould sliding block is assembled on the bottom plate through a guide rail, the drawing block and the side mould sliding block are matched with each other to form a triplet blade body outer profile, and the upper cover is detachably connected above the bottom plate;
s2: pressing a triplet high-pressure guide blade model: placing the oxide ceramic core into a hollow triplet high-pressure guide blade mould, melting a filling mould material, and pressing the filling mould material into the mould to obtain a triplet high-pressure guide blade model wrapping the oxide ceramic core;
s3: bonding the module: bonding the triplet high-pressure guide blade model with a sprue cup, a pouring gate and a riser together to form a module;
s4: preparing an oxide ceramic shell: immersing the module into the slurry, taking out, scattering oxide ceramic sand on the surface of the module, drying to form an oxide ceramic shell on the surface of the module, and heating the module to melt and flow out the filling mold material of the triplet high-pressure guide blade model to obtain the oxide ceramic shell for pouring;
s5: preheating an oxide ceramic shell: wrapping heat preservation cotton outside the oxide ceramic shell, and then putting the oxide ceramic shell into a furnace for preheating, wherein the preheating temperature is 1030-1050 ℃, and the preheating time is not less than 3h;
s6: pouring molten metal: heating the high-temperature alloy liquid to 1460-1480 ℃ in an environment with the vacuum degree less than 1Pa, pouring the molten metal into an oxide ceramic shell within 3-5s, and taking out the oxide ceramic shell after maintaining the vacuum degree for at least 5 min;
s7: taking out the hollow triplet high-pressure guide blade: cutting the triplet high-pressure guide blade, and corroding an oxide ceramic core in the inner cavity of the triplet high-pressure guide blade by using alkali liquor in the environment of 180-220 ℃ and 0.2-0.3 MPa to obtain the hollow triplet high-pressure guide blade.
Further, the step S2 further includes: the mold dimensions were checked using a blue light scanner and the integrity of the oxide ceramic cores was checked using an X-ray scanner.
Further, in the step S3, the module includes two triplet high-pressure guide vane models, a sprue cup, two runners, two sprues, a plurality of ingates and a plurality of feeding heads, two rectangular runner frames are formed by the runners and the two sprues, two triplet high-pressure guide vane models are symmetrically adhered to two sides of the runner frames, the triplet high-pressure guide vane models are vertically placed, an exhaust side of the triplet high-pressure guide vane models faces upwards, the sprue cup is connected above the two triplet high-pressure guide vane models, the ingates are respectively located at a large mounting plate and a small mounting plate of the triplet high-pressure guide vane models, the ingates are connected with the sprues, the feeding heads are located at threaded holes on the side edge of the large mounting plate of the triplet high-pressure guide vane models, and the feeding heads are connected with the sprues.
Further, the step S4 further includes: degreasing the mould set surface before immersing the mould set into the slurry.
Further, the slurry in the step S4 includes ceramic powder, grain refiner, binder, wetting agent and defoaming agent.
Further, in the step S4, the operations of immersing the die set in the slurry, scattering the oxide ceramic sand, and drying are repeated 7-8 times to form 7-8 oxide ceramic coatings on the surface of the die set.
Further, the step S5 of wrapping the insulating cotton outside the oxide ceramic shell specifically includes: the feeding head and the inner pouring gate of the oxide ceramic shell are wrapped with a layer of heat preservation cotton with the thickness of 20mm, the exhaust edge of the blade is wrapped with a layer of heat preservation cotton with the thickness of 3mm, the oxide ceramic shell is integrally wrapped with the heat preservation cotton with the thickness of 20mm, and the mounting plate threaded hole corresponding to the triplet high-pressure guide blade below the oxide ceramic shell is subjected to windowing treatment. .
The beneficial effect of this scheme: (1) The invention adopts the mode of integral pressing to prepare the triplet high-pressure guide blade model, and compared with the mode of firstly pressing the single blade and then assembling, welding and splicing the triplet blade which is usually used, the model has better size consistency, smaller model deformation, higher production efficiency and lower cost.
(2) The method of the invention adopts the oxide ceramic shell-wrapped heat insulation cotton to ensure the air exhaust edge filling effect of the blade and prevent the air exhaust edge from generating the insufficient injection defect, the cooling speed of the feeding head and the inner pouring gate can be slowed down by processing the feeding head and the inner pouring gate by wrapping the heat insulation cotton, the feeding effect is improved, the cooling speed of a hot junction part can be accelerated by windowing processing at a local position, thereby reducing the loosening tendency, the cotton wrapping of the whole module can reduce the heat loss in the module transferring process, and the generation of chilling crystal and crack can be prevented.
(3) The designed preheating temperature of 1030-1050 ℃ can fully ensure the fluidity and the mold filling effect of molten metal, and the pouring temperature of 1480-1500 ℃ can reduce the loosening defect in the casting solidification process, thereby improving the casting qualification rate.
Drawings
FIG. 1 is a schematic flow chart of an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a hollow triplet high-pressure guide blade mold according to an embodiment of the invention;
FIG. 3 is a front view of a module in an embodiment of the present invention;
FIG. 4 is a side view of an embodiment of a module in accordance with the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Reference numerals in the drawings of the specification include: the mold comprises a bottom plate 1, a side mold slide block 2, a drawing block 3, an upper cover 4, a mold core slot 5, a triplet high-pressure guide blade model 6, a sprue cup 7, a cross gate 8, a sprue gate 9, an inner sprue gate 10 and a feeding head 11.
Examples
Substantially as shown in figure 1: a casting method of a high-temperature alloy hollow triplet high-pressure guide blade comprises the following steps:
s1: the method comprises the following steps of manufacturing a hollow triplet high-pressure guide blade mould, and combining a figure 2, wherein the mould comprises a bottom plate 1, a side mould sliding block 2, a drawing block 3 and an upper cover 4, a core slot is arranged on the side mould sliding block 2, the side mould sliding block 2 is assembled on the bottom plate 1 through a guide rail, the drawing block 3 and the side mould sliding block 2 are matched with each other to form a triplet blade body outer profile, and the upper cover 4 is detachably connected above the bottom plate;
s2: pressing a triplet high-pressure guide blade model 6: placing an oxide ceramic core into a hollow triplet high-pressure guide blade mould, melting a filling mould material, pressing the filling mould material into the mould to obtain a triplet high-pressure guide blade model 6 wrapping the oxide ceramic core, taking the triplet high-pressure guide blade out of the mould, checking the size of the model by using a blue light scanner, and checking the integrity of the oxide ceramic core by using an X-ray scanner;
s3: bonding the module: combining with the drawings shown in fig. 3 and 4, bonding a triplet high-pressure guide blade model 6 with a sprue cup 7, pouring gates and feeding heads 11 together to form a module, wherein the module comprises two triplet high-pressure guide blade models 6, one sprue cup 7, two cross runners 8, two sprue gates 9, a plurality of ingates 10 and a plurality of feeding heads 11, the two cross runners 8 and the two sprue gates 9 form a rectangular runner frame, the two triplet high-pressure guide blade models 6 are symmetrically bonded on two sides of the runner frame, the triplet high-pressure guide blade model 6 is vertically arranged, an exhaust edge of the triplet high-pressure guide blade model 6 faces upwards, the sprue cup 7 is connected above the triplet high-pressure guide blade model 6, one ingate 10 is bonded at each of three blade body positions on the side surface of a large mounting plate on the air inlet side of the triplet high-pressure guide blade model 6 and connected with the sprue gates 9, two ingates 10 are bonded at the rib position of a small mounting plate on the air inlet side and connected with the sprue gates 9;
s4: preparing an oxide ceramic shell: removing oil stains on the surface of the module, immersing the module into slurry, and then taking out the module, wherein the slurry comprises ceramic powder, a grain refiner, a binder, a wetting agent and a defoaming agent, scattering oxide ceramic sand on the surface of the module and drying the module, repeating the operation of immersing the module into the slurry, scattering the oxide ceramic sand and drying the module for 7-8 times (preferably 8 times in the embodiment), forming 7-8 layers of oxide ceramic coatings on the surface of the module, and finally forming an oxide ceramic shell on the surface of the module; the heating module melts and flows out the filling mould material of the triplet high-pressure guide blade model 6 to obtain an oxide ceramic shell for pouring;
s5: preheating an oxide ceramic shell: the feeding head 11 and the inner sprue 10 of the oxide ceramic shell are wrapped with a layer of heat preservation cotton with the thickness of 20mm, the exhaust edge of each blade is wrapped with a layer of heat preservation cotton with the thickness of 3mm, the oxide ceramic shell is integrally wrapped with the heat preservation cotton with the thickness of 20mm, the screwed hole of the mounting plate corresponding to the triplet high-pressure guide blade below the oxide ceramic shell is subjected to windowing treatment, and then the oxide ceramic shell is put into a furnace for preheating at the temperature of 1030-1050 ℃ (preferably 1040 ℃ in the embodiment) for 3 hours;
s6: pouring molten metal: heating the high-temperature alloy liquid to 1460-1480 ℃ in the environment with the vacuum degree less than 1Pa (preferably 1470 ℃ in the embodiment), pouring the molten metal into the oxide ceramic shell within 3-5s, and taking out the oxide ceramic shell after keeping the vacuum degree for 5 min;
s7: taking out the hollow triplet high-pressure guide blade: cutting the triplet high-pressure guide blade, and corroding an oxide ceramic core in the inner cavity of the triplet high-pressure guide blade by using alkali liquor under the environment of 180-220 ℃ and 0.2-0.3 MPa of pressure intensity (preferably 200 ℃ and 0.3MPa of pressure intensity in the embodiment) to obtain the hollow triplet high-pressure guide blade.
The beneficial effects of this embodiment: (1) The invention adopts the integral pressing mode to prepare the triplet high-pressure guide blade model 6, and compared with the commonly used mode of firstly pressing the monomer blades and then assembling, welding and splicing the triplet blades, the model has the advantages of better size consistency, smaller model deformation, higher production efficiency and lower cost.
(2) The method of the invention adopts the oxide ceramic shell-wrapped heat insulation cotton to ensure the air exhaust edge mold filling effect of the blade and prevent the air exhaust edge from short injection defect, the cooling speed of the feeding head 11 and the inner pouring gate 10 can be slowed down by processing the feeding head 11 and the inner pouring gate 10 wrapped with the heat insulation cotton, the feeding effect is improved, the cooling speed of a hot junction part can be accelerated by windowing processing of a local position, thereby reducing the loosening tendency, the cotton wrapping of the whole module can reduce the heat loss in the module transferring process, and the generation of chilling crystal and crack can be prevented.
(3) The designed preheating temperature of 1030-1050 ℃ can fully ensure the fluidity and the mold filling effect of molten metal, and the pouring temperature of 1480-1500 ℃ can reduce the loosening defect in the casting solidification process, thereby improving the casting qualification rate.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The foregoing is merely an example of the present invention, and common general knowledge in the field of known specific structures and characteristics is not described herein in any greater extent than that known in the art at the filing date or prior to the priority date of the application, so that those skilled in the art can now appreciate that all of the above-described techniques in this field and have the ability to apply routine experimentation before this date can be combined with one or more of the present teachings to complete and implement the present invention, and that certain typical known structures or known methods do not pose any impediments to the implementation of the present invention by those skilled in the art. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be defined by the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.
Claims (7)
1. A casting method of a high-temperature alloy hollow triplet high-pressure guide blade is characterized by comprising the following steps: the method comprises the following steps:
s1: the method comprises the following steps of manufacturing a hollow triplet high-pressure guide blade mould, wherein the mould comprises a bottom plate, a side mould sliding block, a drawing block and an upper cover, wherein a core slot is formed in the side mould sliding block, the side mould sliding block is assembled on the bottom plate through a guide rail, the drawing block and the side mould sliding block are matched with each other to form a triplet blade body outer profile, and the upper cover is detachably connected above the bottom plate;
s2: pressing a triplet high-pressure guide blade model: placing the oxide ceramic core into a hollow triplet high-pressure guide blade mould, melting a filling mould material, and pressing the filling mould material into the mould to obtain a triplet high-pressure guide blade model wrapping the oxide ceramic core;
s3: bonding the module: bonding the triplet high-pressure guide blade model with a sprue cup, a pouring gate and a riser together to form a module;
s4: preparing an oxide ceramic shell: immersing the module into the slurry, taking out, scattering oxide ceramic sand on the surface of the module, drying to form an oxide ceramic shell on the surface of the module, and heating the module to melt and flow out the filling mold material of the triplet high-pressure guide blade model to obtain the oxide ceramic shell for pouring;
s5: preheating an oxide ceramic shell: wrapping heat preservation cotton outside the oxide ceramic shell, and then putting the oxide ceramic shell into a furnace for preheating, wherein the preheating temperature is 1030-1050 ℃, and the preheating time is not less than 3h;
s6: pouring molten metal: heating the high-temperature alloy liquid to 1460-1480 ℃ in an environment with the vacuum degree less than 1Pa, pouring the molten metal into an oxide ceramic shell within 3-5s, and taking out the oxide ceramic shell after maintaining the vacuum degree for at least 5 min;
s7: taking out the hollow triplet high-pressure guide blade: cutting the triplet high-pressure guide blade, and corroding an oxide ceramic core in the inner cavity of the triplet high-pressure guide blade by using alkali liquor in the environment of 180-220 ℃ and 0.2-0.3 MPa of pressure to obtain the hollow triplet high-pressure guide blade.
2. The method for casting a superalloy hollow triplet high pressure guide vane of claim 1, wherein: the step S2 further includes: the mold dimensions were checked using a blue light scanner and the integrity of the oxide ceramic cores was checked using an X-ray scanner.
3. The method for casting a superalloy hollow triplet high pressure guide vane of claim 1, wherein: in the step S3, the module includes two triplet high-pressure guide vane models, a sprue cup, two runners, a plurality of ingates and a plurality of feeding heads, two the rectangular runner frame is formed by the runners and the two runners, two triplet high-pressure guide vane models are symmetrically adhered to two sides of the runner frame, the triplet high-pressure guide vane models are vertically placed, an exhaust edge of the triplet high-pressure guide vane models faces upwards, the sprue cup is connected above the two triplet high-pressure guide vane models, the ingates are respectively located at a large mounting plate and a small mounting plate of the triplet high-pressure guide vane models, the ingates are connected with the runners, and the feeding heads are located at threaded holes on the side edge of the large mounting plate of the triplet high-pressure guide vane models and connected with the runners.
4. The method for casting a superalloy hollow triplet high pressure guide vane of claim 1, wherein: the step S4 further includes: degreasing the mould set surface before immersing the mould set into the slurry.
5. The method for casting a superalloy hollow triplet high pressure guide vane of claim 4, wherein: the slurry in the step S4 comprises ceramic powder, a grain refiner, a binder, a wetting agent and a defoaming agent.
6. The method for casting a superalloy hollow triplet high pressure guide vane of claim 5, wherein: in the step S4, the operations of immersing the die set into the slurry, scattering oxide ceramic sand and drying are repeated for 7-8 times, and 7-8 oxide ceramic coatings are formed on the surface of the die set.
7. The method for casting a superalloy hollow triplet high pressure guide vane of claim 3, wherein: the step S5 of wrapping the oxide ceramic shell with the heat-preservation cotton specifically comprises the following steps: the feeding head and the inner pouring gate of the oxide ceramic shell are wrapped with a layer of heat insulation cotton with the thickness of 20mm, the exhaust edge of each blade is wrapped with a layer of heat insulation cotton with the thickness of 3mm, the oxide ceramic shell is integrally wrapped with the heat insulation cotton with the thickness of 20mm, and the threaded hole of the mounting plate corresponding to the triplet high-pressure guide blade below the oxide ceramic shell is subjected to windowing treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211355581.1A CN115889702A (en) | 2022-11-01 | 2022-11-01 | Casting method of high-temperature alloy hollow triplet high-pressure guide blade |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211355581.1A CN115889702A (en) | 2022-11-01 | 2022-11-01 | Casting method of high-temperature alloy hollow triplet high-pressure guide blade |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115889702A true CN115889702A (en) | 2023-04-04 |
Family
ID=86487514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211355581.1A Pending CN115889702A (en) | 2022-11-01 | 2022-11-01 | Casting method of high-temperature alloy hollow triplet high-pressure guide blade |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115889702A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117047041A (en) * | 2023-10-12 | 2023-11-14 | 中国航发沈阳黎明航空发动机有限责任公司 | Column crystal casting system structure and casting process of triplet solid guide vane |
-
2022
- 2022-11-01 CN CN202211355581.1A patent/CN115889702A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117047041A (en) * | 2023-10-12 | 2023-11-14 | 中国航发沈阳黎明航空发动机有限责任公司 | Column crystal casting system structure and casting process of triplet solid guide vane |
| CN117047041B (en) * | 2023-10-12 | 2023-12-19 | 中国航发沈阳黎明航空发动机有限责任公司 | Column crystal casting system structure and casting process of triplet solid guide vane |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111496187B (en) | Precision investment casting method for single crystal duplex hollow guide blade | |
| CN111451447B (en) | Precision casting method of solid duplex single crystal guide blade | |
| CN102019354B (en) | Directional solidification method of ultra-thin and long shrouded blade | |
| CN109622888B (en) | Casting forming process of complex high-temperature alloy multi-connection guide blade casting | |
| CN104308076B (en) | The wax-pattern combination of the hollow turborotor of a kind of tetrad and fine casting method thereof | |
| CN110090927B (en) | Method for solving stress cracks of aviation stainless steel investment casting | |
| US20090165988A1 (en) | Turbine airfoil casting method | |
| CN106001513B (en) | A kind of preparation method of precision-investment casting single crystal super alloy thin-walled sample | |
| CN111014617B (en) | Forming method of thin-wall volute casing with spiral structure based on antigravity casting | |
| CN104014748B (en) | The method utilizing the overall shell mould of formwork roasting apperance gasification, and combustion preparation | |
| CN115889702A (en) | Casting method of high-temperature alloy hollow triplet high-pressure guide blade | |
| CN100563870C (en) | The preparation method of hollow wax matrix | |
| CN104308082A (en) | Pouring method of hollow turbine guide vane | |
| CN109773124A (en) | A kind of francis turbine runner integral casting process | |
| CN112387931A (en) | Gravity casting mold of new energy water-cooled motor shell end cover and casting process thereof | |
| CN114210926B (en) | Turbine blade investment casting shell and casting process thereof | |
| CN113976824B (en) | Method for preventing mixed crystals from being generated at free end of conjuncted single crystal guide blade core | |
| CN110976806A (en) | Casting method of thin-wall aluminum alloy casting | |
| CN109332631B (en) | Low-temperature die-casting process for communication box body | |
| CN104690229B (en) | A kind of turbojet engine tail sprays foundry engieering | |
| CN112475232A (en) | Large ceramic shell flow choking method for allowance-free precision casting | |
| CN112705671B (en) | Wax module structure of cover plate block casting cantilever structure single crystal blade | |
| CN117483663A (en) | Aviation turbofan engine connotation spray pipe pouring system and integral casting method | |
| CN105562613B (en) | A kind of one-time formed method of aero-engine porous plate diverging cooling turbo blade ceramic core | |
| CN112605346A (en) | Casting method of hook body for hook of lifting system of ultra-deep well petroleum drilling machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |