CN116727630A - Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity - Google Patents
Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity Download PDFInfo
- Publication number
- CN116727630A CN116727630A CN202310618380.4A CN202310618380A CN116727630A CN 116727630 A CN116727630 A CN 116727630A CN 202310618380 A CN202310618380 A CN 202310618380A CN 116727630 A CN116727630 A CN 116727630A
- Authority
- CN
- China
- Prior art keywords
- injection
- magnesium alloy
- assembly
- channel
- solid
- 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
- 238000002347 injection Methods 0.000 title claims abstract description 222
- 239000007924 injection Substances 0.000 title claims abstract description 222
- 229910000861 Mg alloy Inorganic materials 0.000 title claims abstract description 181
- 238000000034 method Methods 0.000 title claims abstract description 45
- 238000000465 moulding Methods 0.000 title claims abstract description 39
- 230000008569 process Effects 0.000 title claims abstract description 37
- 230000009974 thixotropic effect Effects 0.000 title claims abstract description 29
- 239000000463 material Substances 0.000 claims abstract description 120
- 238000001816 cooling Methods 0.000 claims abstract description 85
- 238000002844 melting Methods 0.000 claims abstract description 81
- 230000008018 melting Effects 0.000 claims abstract description 80
- 239000007787 solid Substances 0.000 claims abstract description 79
- 239000013078 crystal Substances 0.000 claims abstract description 66
- 238000010008 shearing Methods 0.000 claims abstract description 63
- 238000004781 supercooling Methods 0.000 claims abstract description 24
- 239000007791 liquid phase Substances 0.000 claims abstract description 23
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- 230000009466 transformation Effects 0.000 claims abstract description 4
- 239000002002 slurry Substances 0.000 claims description 86
- 239000007790 solid phase Substances 0.000 claims description 33
- 238000010438 heat treatment Methods 0.000 claims description 28
- 238000007789 sealing Methods 0.000 claims description 27
- 239000002245 particle Substances 0.000 claims description 23
- 230000009471 action Effects 0.000 claims description 21
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 17
- 229910052749 magnesium Inorganic materials 0.000 claims description 17
- 239000011777 magnesium Substances 0.000 claims description 17
- 239000000956 alloy Substances 0.000 claims description 16
- 229910045601 alloy Inorganic materials 0.000 claims description 13
- 238000013461 design Methods 0.000 claims description 7
- 238000011049 filling Methods 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 7
- 238000001746 injection moulding Methods 0.000 claims description 4
- 238000001125 extrusion Methods 0.000 claims description 3
- 238000000265 homogenisation Methods 0.000 claims description 2
- 230000035515 penetration Effects 0.000 claims description 2
- RZJQYRCNDBMIAG-UHFFFAOYSA-N [Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Zn].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn] Chemical group [Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Zn].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn] RZJQYRCNDBMIAG-UHFFFAOYSA-N 0.000 claims 1
- 238000006073 displacement reaction Methods 0.000 claims 1
- 239000000047 product Substances 0.000 description 15
- 238000010586 diagram Methods 0.000 description 12
- 230000006872 improvement Effects 0.000 description 11
- 238000004537 pulping Methods 0.000 description 9
- 239000000155 melt Substances 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 238000010099 solid forming Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- 239000012768 molten material Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 238000000280 densification Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000010992 reflux Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 210000001787 dendrite Anatomy 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000012265 solid product Substances 0.000 description 2
- 230000002195 synergetic effect Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000001996 bearing alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 239000000109 continuous material Substances 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000003562 lightweight material Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000010119 thixomolding Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/007—Semi-solid pressure die casting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/02—Hot chamber machines, i.e. with heated press chamber in which metal is melted
- B22D17/04—Plunger machines
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/20—Accessories: Details
- B22D17/2015—Means for forcing the molten metal into the die
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/20—Accessories: Details
- B22D17/2015—Means for forcing the molten metal into the die
- B22D17/203—Injection pistons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/20—Accessories: Details
- B22D17/32—Controlling equipment
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
The invention discloses a thixotropic molding process of a large-injection-amount spherical crystal magnesium alloy, which adopts the cooperation of continuous five-stage temperature control, shearing and injection processes to promote the magnesium alloy to be converted into semi-solid spherical crystals and mold; stage 1: melting; stage 2: a near liquid phase; stage 3: short-time low supercooling; stage 4: semi-solid isothermal spherical crystal transformation; stage 5: high-speed injection cooling molding; the invention also discloses a large-injection-amount spherical crystal magnesium alloy thixotropic molding device which comprises a first-order material melting assembly, a cooling conduit assembly, a second-order shearing and injection assembly and a cavity assembly, wherein the magnesium alloy sequentially passes through the first-order material melting assembly, the cooling conduit assembly, the second-order shearing and injection assembly and the cavity assembly to finish product production. The invention provides a thixotropic molding process and equipment for large-injection spherical crystal magnesium alloy, which have the advantages of large injection quantity, uniform spherical crystal, good process connectivity and suitability for high-performance large-piece products.
Description
Technical Field
The invention relates to the field of material synthesis, in particular to a thixotropic molding process and equipment for a large-injection spherical crystal magnesium alloy.
Background
Under the background of double carbon, light weight is an important trend of high-end manufacturing development, magnesium alloy is the lightest metal structural material which can be used in the world at present, for example, materials such as substituted steel, aluminum and the like are applied to the fields of automobiles, aviation and the like, carbon reduction can be effectively realized, and the reserve of magnesium in the nature is extremely abundant, so that the magnesium alloy is a key light weight material for development in the future industry.
Among various forming techniques of magnesium alloy, the semi-solid forming technique is known as the most promising forming technique of 21 st century magnesium alloy, because the semi-solid forming technique can remarkably improve the production safety and environmental protection. Semi-solid is generally understood to mean that the alloy is controlled to a two-phase intermediate temperature comprising a liquid phase and a solid phase, while under external or internal induction conditions the structure is transformed into a slurry comprising a homogeneous solid phase distributed in the liquid phase, which slurry has specific thixotropic mechanical behavior, including shear-thinning and isothermal transient rheological properties, allowing laminar filling to obtain highly dense parts. Obtaining ideal slurry is a key link of semi-solid technology, and semi-solid product performance not only requires temperature conditions, but also essentially requires microstructure conditions of the slurry. At present, a relatively mature magnesium alloy semi-solid forming process is a thixotropic injection molding method (Thixomolding) promoted and developed in Japan, and the magnesium alloy low-oxidation forming can be realized through continuous shearing, one-time continuous heating and injection of a single screw, so that the magnesium alloy semi-solid forming process is applied to the production and application of small products such as notebook computer shells and the like. But for large gram weight automobile parts and the like, the size and the structural complexity are improved, the service performance requirement is higher, the injection quantity of the sizing agent is greatly improved, and the spherical crystals in the slurry tissue with large injection quantity are required to be ensured to be sufficiently fine and uniform, so that the slurry tissue has sufficient filling capacity, mechanical property and corrosion property. At present, the traditional technology is limited by technical route, and can only achieve semi-solid forming of less than 5kg of heavy magnesium products, and cannot realize large-scale production. Therefore, development of novel magnesium alloy thixotropic molding process and equipment with larger injection quantity, uniform spherical crystal and good process continuity and suitable for high-performance large-piece products is urgently needed.
Through searching, the Chinese patent with the publication number of CN107671260A relates to a semisolid injection molding machine with multi-station injection, wherein: by arranging two semi-solid injection mechanisms to inject the semi-solid magnesium alloy, the injection quantity is effectively increased, the flow length ratio is effectively reduced, and the structure is suitable for the occasion of producing thin-wall or thick-wall magnesium alloy products with high quality and flow length ratio. The technology of the invention utilizes the traditional thixotropic injection molding mode, and increases the injection quantity by setting two sets of injection mechanisms, but the technology has the following defects: the junction of two melts in the cavity is easy to be unfused, so that the performance of the position is weak; the mold needs to be provided with two pouring gates, which is not common with the tradition of the industry field mold; semi-solid pulping still adopts a once continuous heating method, and spherical crystal form control is limited, so that the filling capacity and the product performance are easy to be low.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: provides a thixotropic molding process and equipment for large-injection spherical crystal magnesium alloy, which has large injection quantity, uniform spherical crystal and good process connectivity and is suitable for high-performance large-piece products.
The invention solves the problems by adopting the following technical scheme: a thixotropic molding process for large-injection spherical crystal magnesium alloy adopts continuous five-stage temperature control, shearing and injection processes to cooperate with each other, so that the magnesium alloy is promoted to be converted into semi-solid spherical crystal and molded;
Stage 1: melting, namely, adopting a first-order melting component to carry out tunnel rapid heating and softening on magnesium alloy particles until the magnesium alloy particles are melted to be above a liquidus line, and simultaneously gradually self-densifying under the extrusion and pushing of a melting screw rod, and keeping no air from being involved after liquefaction;
stage 2: near liquid phase, at the end position of the first-order material component, the magnesium alloy is controlled to be homogenized at the temperature of 10-30 ℃ above the near liquidus line at constant temperature, so that the alloy structure is converted into a pure liquid phase or an extremely low solid phase state;
stage 3: the short-time low supercooling is realized by adopting a temperature control cooling conduit assembly, and the temperature control cooling conduit assembly is connected with the first-order melting assembly and is used for providing short-time low supercooling conditions for flowing magnesium melt so as to quickly generate a large amount of semi-solid primary crystals in a near-liquid alloy tissue;
stage 4: semi-solid isothermal spherical crystal transformation adopts a horizontal second-order shearing and injection assembly, is communicated with a temperature control cooling catheter assembly and is used for providing semi-solid isothermal heat treatment and injection screw shearing action for low supercooled magnesium alloy, so that solid phase in semi-solid primary crystals in magnesium alloy tissues is penetrated and surrounded by low melting point liquid phase to be refined and fully spheroidized, and is transformed into spherical crystal semi-solid slurry;
stage 5: and (3) performing high-speed injection cooling molding, namely completing injection action of spherical crystal semi-solid slurry with good thixotropic property under high pressure and high speed, filling the slurry into a cavity component, and performing cooling molding to form a densified magnesium alloy product.
Compared with the prior art, the invention has the advantages that:
1. precise control of semi-solid spherical crystal slurry structure: the method comprises the steps of adopting a synergistic effect of multi-stage temperature control and shearing, firstly, rapidly heating magnesium particles to be above a liquidus line in a first stage, and self-densifying a melt by spiral propulsion, so as to promote preparation conditions for the generation of supercooled solid phase, wherein the temperature cannot be too high, the temperature is stably controlled to be 10-20 ℃ above a near liquidus line, otherwise, magnesium alloy is easy to generate oxidation and material reflux; in the second stage, when the magnesium melt flows through a cooling conduit, the low supercooling degree promotes supercooling nucleation in a liquid phase tissue, and the magnesium melt is converted into a melt containing a large amount of primary solid phase in a short time, but the supercooling degree is not excessively high and is controlled to be 15-30 ℃ below a liquidus line, otherwise, the primary solid phase rate is excessively high, so that the melt is easily blocked in the conduit; in the third stage, the primary solid phase is heated for the second time, semi-solid isothermal heat treatment is utilized to promote the rounding of crystal grains, and simultaneously, the shearing action of a screw is assisted, so that the solid phase is thinned and uniformly distributed, and spherical crystal semi-solid slurry with very excellent thixotropic property is obtained;
2. semi-solid pulping of magnesium alloy with large injection quantity: the three-stage pulping mode not only effectively improves pulping quality and efficiency, but also forms a serial process, and avoids the problem of insufficient heating power of a certain single component; the system also has the advantages of good pulping monitoring performance and easy maintenance performance, definite functional partition and convenient operation when maintaining or replacing a single component.
As an improvement of the invention, in the stage 1, the magnesium alloy adopts the specification of granularity between 0.5 and 5mm and keeps the dry state, the magnesium alloy material needs to be selected from the types with semi-solid process window intervals above 50 ℃, and by the improvement, the magnesium alloy particles with uniform granularity can be melted by adopting more accurate temperature, so that the problems of oxidization and material backflow caused by overhigh melting temperature can be avoided; the magnesium alloy is kept dry, so that the water is prevented from being gasified after being subjected to high temperature, bubbles are formed in the first-order material component, and the compactness of the magnesium alloy is influenced; the semi-solid process window with the temperature of more than 50 ℃ is selected to ensure the processable space range of the magnesium alloy, and if the process window is too small, the magnesium alloy is easy to generate oxidization and material reflux or the primary solid phase rate is too high.
As an improvement of the invention, in the stage 2, the end set temperature of the first-order material component is 10-20 ℃ above the liquidus temperature of the magnesium alloy; the rotating speed of the melting screw is 100r/min;
in the stage 3, the low supercooling condition is 10-30 ℃ below the liquidus temperature of the magnesium alloy;
in the stage 4, the constant temperature set temperature of the second-order shearing and injection assembly is 5-10 ℃ below the liquidus temperature, and the corresponding slurry solid phase rate is 10-30%; the rotational speed of the injection screw is 60r/min;
In stage 5, the mold temperature was 280℃and the injection speed was 5m/s.
The invention solves the problems by adopting the following technical scheme: the large injection quantity spherical magnesium alloy thixotropic molding equipment comprises a first-order material component, a cooling conduit component, a second-order shearing and injection component and a cavity component, wherein magnesium alloy sequentially passes through the first-order material component, the cooling conduit component, the second-order shearing and injection component and the cavity component to finish product production, the first-order material component comprises a material melting channel, a material melting screw and a material melting heater, the material melting screw is arranged on the axis of the material melting channel and used for pushing self-densification liquid magnesium alloy and discharging air, the material melting screw simultaneously pushes the magnesium alloy to the cooling conduit component in a rotating and axially moving mode, the material melting heater is arranged on the outer side of the material melting channel and used for heating the material melting channel, the temperature of the material melting channel is kept above the liquidus of the magnesium alloy, the cooling conduit component comprises a cooling channel and a low-temperature heater, the cooling channel is communicated with the material melting channel, the outer side of the low-temperature heater is arranged on the cooling conduit component and used for guaranteeing the short-time low supercooling operation, the first-order material melting screw is arranged on the axis of the material melting component and the material melting channel and used for pushing the self-densification liquid magnesium alloy and discharging air, the material melting screw is arranged on the outer side of the material melting channel and used for heating the magnesium alloy in a mode of axial movement, the material melting channel is kept above the liquidus of the magnesium alloy, and the cooling conduit component is arranged on the cooling channel, the cooling conduit component is used for heating the injection channel.
Compared with the prior art, the invention has the advantages that:
1. precise control of semi-solid spherical crystal slurry structure: the method comprises the steps of adopting a synergistic effect of multi-stage temperature control and shearing, firstly, rapidly heating magnesium particles to be above a liquidus line in a first stage, and self-densifying a melt by spiral propulsion, so as to promote preparation conditions for the generation of supercooled solid phase, wherein the temperature cannot be too high, the temperature is stably controlled to be 10-20 ℃ above a near liquidus line, otherwise, magnesium alloy is easy to generate oxidation and material reflux; in the second stage, when the magnesium melt flows through a cooling conduit, the low supercooling degree promotes supercooling nucleation in a liquid phase tissue, and the magnesium melt is converted into a melt containing a large amount of primary solid phase in a short time, but the supercooling degree is not excessively high and is controlled to be 15-30 ℃ below a liquidus line, otherwise, the primary solid phase rate is excessively high, so that the melt is easily blocked in the conduit; in the third stage, the primary solid phase is heated for the second time, semi-solid isothermal heat treatment is utilized to promote the rounding of crystal grains, and simultaneously, the shearing action of a screw is assisted, so that the solid phase is thinned and uniformly distributed, and spherical crystal semi-solid slurry with very excellent thixotropic property is obtained;
2. semi-solid pulping of magnesium alloy with large injection quantity: the three-stage pulping mode not only effectively improves pulping quality and efficiency, but also forms a serial process, and avoids the problem of insufficient heating power of a certain single component; the pulping monitoring performance and the easy maintenance performance are good, the functional partition is clear, and the operation is convenient when a single component is maintained or replaced;
3. Semi-solid continuous storage of magnesium alloy with large injection quantity: according to the invention, in the first-order material melting assembly horizontally arranged, the material melting screw is simultaneously connected with the oil cylinder and the motor in a transmission manner, so that the material melting screw can axially move and rotate in the process of mixing molten materials, when an injection channel is full, the material melting screw continuously keeps rotating in the process of starting injection, the material melting screw does not need to stop, and can retreat, the storage space of the material melting channel is enlarged, the molten materials are temporarily stored in the material melting channel, after the second-order shearing and injection assembly finishes injection, the material melting screw rotates and is pushed forward, and the temporarily stored molten materials are pushed into the second-order shearing and injection assembly by pressure, so that the continuous material storage and injection operation of a large injection quantity of semisolid magnesium alloy are realized, the first-order material melting assembly continuously keeps a rotating state, the molten materials are heated more uniformly and are not easy to be solidified in advance, the period of each time is ensured to be short, the production efficiency is improved, and the product qualification rate is high;
4. the performance advantages of the semi-solid magnesium alloy are exerted: first, the process of the present inventionThe equipment can realize control to ensure that the magnesium alloy contains more than 10 percent of uniform spherical crystal semi-solid slurry, the slurry has good fluidity, and in the cooling duct component, high-speed laminar flow filling is carried out to ensure that the defect of air holes is greatly reduced, so that the high-density molding of large magnesium alloy parts can be realized; secondly, the magnesium alloy product has higher mechanical property, fine grains in the semi-solid solidification structure promote the fine crystal strengthening effect firstly, spherical crystals are beneficial to the coordinated plastic deformation of the alloy structure and improve the elongation at break, the semi-solid product can be subjected to T6 heat treatment, bubbling is not generated, and the comprehensive mechanical property of the final casting can be improved by more than 15% compared with the traditional die casting molding; thirdly, the magnesium alloy product has higher corrosion resistance, on one hand, mg in spherical crystal structure 17 Al 12 The second phase is thinned, the micro-galvanic corrosion is weakened, and on the other hand, the dense alloy structure can uniformly block the expansion of the surface corrosion layer, so that the occurrence probability of pitting corrosion is greatly reduced;
5. the whole process is carried out in the closed machine barrel and the connecting piece, so that the method has the advantages of no combustion and oxidation risk, good safety, no need of a magnesium alloy melting furnace, low power consumption and low cost, and is an environment-friendly magnesium alloy near-net forming technology.
According to the invention, the injection screw comprises a screw part and a piston part, the piston part is in movable sealing fit with the injection channel, the screw part is arranged between the piston part and the cavity assembly, the joint of the cooling channel and the injection channel is also arranged between the piston part and the cavity assembly, and the injection screw simultaneously injects magnesium alloy in the direction of the cavity assembly in a rotating and axial moving mode; the design of the screw part can promote the magnesium alloy slurry to flow forwards in the rotating and pushing process of the injection screw so as to avoid the countercurrent of the magnesium alloy slurry to the direction of the cooling duct component, and simultaneously, when the second-order shearing and injection component receives the magnesium alloy slurry, the rotation of the screw part can enable the magnesium alloy slurry to push to the direction of the cavity component, thereby avoiding the retention of the magnesium alloy slurry and avoiding the shape and the blockage, and further reducing the design of the check valve on the cooling duct component and the production cost required by the check valve; and because of the design of the screw rod part, the injection screw rod can inject the magnesium alloy slurry to a position closer to the cavity assembly, so that the magnesium alloy slurry is injected more fully, the second-order shearing and the excess materials in the injection assembly are reduced, and the reasonable utilization of the magnesium alloy slurry and the later material cleaning are facilitated; meanwhile, the movable sealing fit between the piston part and the injection channel can ensure the sufficiency of magnesium alloy slurry injection, avoid the conditions of permeation and flash of the magnesium alloy slurry from the piston part to the injection channel, avoid the situation that the magnesium alloy slurry permeates from one side of the piston part far away from the screw part, but the equipment is in long-term use, and the piston part is movable fit with the injection channel, so that the matching tightness between the piston part and the injection channel is inevitably damaged, the conditions of permeation and flash are caused, and the structural design of the screw part reduces the pressure of the magnesium alloy slurry to the piston part during injection, also can reduce the permeation pressure to the piston part, reduce the requirements of the matching tightness between the piston part and the injection channel, reduce the possibility of permeation and flash, and improve the use safety of the equipment.
As an improvement, the cooling channel is arranged perpendicular to the injection channel, the injection channel is provided with a feeding port communicated with the cooling channel, the feeding port is arranged along the rotation tangential direction of the screw part, and by the improvement, the second-order shearing and injection assembly can receive the magnesium alloy slurry more smoothly and faster, and the magnesium alloy slurry is not easy to form spiral and accumulated materials in the feeding port.
According to the invention, the injection screw is further provided with the injection part, the injection part is arranged at one end of the screw part, which is close to the cavity, a connecting rod is arranged between the injection part and the screw part, a check ring is movably sleeved on the connecting rod, the outer diameter of the connecting rod is matched with the inner diameter of the check ring, a plurality of material passing grooves for passing materials are circumferentially arranged on the connecting rod, by the improvement, the check ring is designed to prevent the magnesium alloy slurry from flowing backwards, when the magnesium alloy slurry is injected into the cavity assembly, the check ring moves towards the cavity assembly, the magnesium alloy slurry sequentially passes through the interval between the check ring and the screw part and the material passing grooves for injection, when the second-order shearing and injection assembly receives the magnesium alloy slurry from the cooling conduit assembly, the injection screw is retracted, the magnesium alloy slurry can flow back because of the retracted vacuum low pressure, the check ring moves towards the screw part and is propped against the direction, the magnesium alloy slurry is prevented from flowing back, the outer diameter of the connecting rod is matched with the inner diameter of the check ring, the connecting rod can be ensured to be coaxial with the check ring, and the magnesium alloy slurry can move along with the check ring in a stable swinging process, and the swing of the check ring can be prevented from moving along the swing.
As an improvement of the invention, the injection part is provided with a guide groove designed along the axial direction, the check ring is provided with a guide block matched with the guide groove, the check ring is also provided with a propping block arranged in the same direction as the guide block, the propping block and the injection part prop against each other to form a material passing hole between the injection part and the check ring, and the injection part is also provided with a plurality of material passing holes.
As an improvement of the invention, the outer side of the non-return ring is provided with a sealing ring, the sealing ring is provided with an adjusting gap, the non-return ring is provided with a sealing ring mounting groove for mounting the sealing ring, the mounting groove is internally provided with a control hole, through the improvement, the sealing ring can be expanded by utilizing the pressure transmissibility of the control hole during injection, thereby achieving the tight fit between the sealing ring and an injection channel, ensuring the tightness between the sealing ring and the injection channel during injection, avoiding the backflow of alloy mixed fluid from the gap between the non-return ring and the injection channel, reducing the pressure, shrinking the sealing ring, forming a gap between the sealing ring and the injection channel, and avoiding the occurrence of rotational friction and moving friction between the non-return ring and the injection channel during bearing alloy mixed fluid.
The invention also provides an improvement, the control hole comprises a first control hole and a second control hole, the first control hole is arranged at one end of the non-return ring close to the injection head, the second control hole is arranged at one end of the non-return ring far away from the injection head, the first control hole is obliquely arranged from inside to outside from the injection head to the direction of the spiral pushing groove, the second control hole is arranged along the radial direction of the connecting rod, and by the improvement, the pressure of the formed sealing ring is more stable and has no impact pressure, so that the instant resistance of the sealing ring is avoided, the sealing stability of the sealing ring is ensured, the impact of the second control hole is small, only the sealing effect of the sealing ring is ensured, and the radial design is adopted, the pressure stroke is reduced, and the sealing effect is quickly achieved.
Drawings
Fig. 1 is a schematic diagram of the overall structure of the present invention.
FIG. 2 is a schematic sectional view of the connection structure of the feed inlet and the screw part.
FIG. 3 is a schematic cross-sectional structure of the connection structure of the feed inlet and the screw part of the invention.
FIG. 4 is a schematic view of the connection structure of the injection part and the non-return ring of the present invention.
FIG. 5 is a schematic view of the connecting section structure of the connecting rod and the non-return ring.
FIG. 6 is a schematic view of the injection part and the connecting rod according to the present invention.
FIG. 7 is a schematic view of the structure of the non-return ring of the present invention.
FIG. 8 is a schematic cross-sectional view of the connection structure of the injection part and the non-return ring of the present invention.
Fig. 9 is a process flow diagram of the present invention.
FIG. 10 is a diagram of pure liquid phase or very low solid phase grains of the magnesium alloy slurry of the present invention at the end of a first-order chemical assembly.
FIG. 11 is a diagram of semi-solid primary crystal grains of the magnesium alloy slurry of the present invention in a cooling conduit assembly.
Fig. 12 is a diagram of spherical semi-solid grains after spheroidization of the magnesium alloy slurry of the present invention in a second order shear and injection assembly.
Fig. 13 is a diagram of a spheroidized semi-solid state grain according to example 1 of the present invention.
Fig. 14 is a diagram of a spheroidized semi-solid state grain according to example 2 of the present invention.
Fig. 15 is a diagram of a spheroidized semi-solid state grain according to example 3 of the present invention.
Fig. 16 is a diagram of spheroidized semi-solid state grains according to example 4 of the present invention.
FIG. 17 is a semi-solid grain diagram of comparative example 1 of the present invention.
Fig. 18 is a semi-solid grain diagram of comparative example 2 of the present invention.
The figure shows: 1. a first-order material melting assembly, 1.1, a material melting channel, 1.2, a material melting screw, 1.3, a material melting heater, 2, a cooling conduit assembly, 2.1, a cooling channel, 2.2, a low-temperature heater, 3, a second-order shearing and injection assembly, 3.1, an injection channel, 3.1.1, a material inlet, 3.2, an injection screw, 3.2.1, a screw part, 3.2.2, a piston part, 3.2.3, an injection part, 3.2.4, a connecting rod, 3.2.5, a material passing groove, 3.2.6, a guide groove, 3.2.7, a material passing hole, 3.3, an injection heater, 4, a cavity assembly, 5, a check ring, 5.1, a guide block, 5.2, a block, 5.3, a material passing hole, 5.4, a sealing ring, 5.4.1, a regulating gap, 5.5, a mounting groove, 5.6, a first control hole, 5.7 and a second control hole.
Detailed Description
Embodiments of the present invention are further described below with reference to the accompanying drawings.
As shown in fig. 1, the large injection quantity spherical magnesium alloy thixotropic molding device comprises a first-order material component 1, a cooling conduit component 2, a second-order shearing and injection component 3 and a cavity component 4, wherein magnesium alloy sequentially passes through the first-order material component 1, the cooling conduit component 2, the second-order shearing and injection component 3 and the cavity component 4 to finish product production, the first-order material component 1 comprises a material melting channel 1.1, a material melting screw 1.2 and a material melting heater 1.3, the material melting screw 1.2 is arranged on the axis of the material melting channel 1.1 and is used for pushing self-compaction liquid magnesium alloy and discharging air, the material melting screw 1.2 simultaneously pushes the magnesium alloy to the cooling conduit component 2 in a rotating and axially moving mode, the material melting heater 1.3 is arranged on the outer side of the material melting channel 1.1 and is used for heating the material melting channel 1.1, the temperature of the material melting channel 1.1 is kept above a magnesium alloy liquidus line, the cooling conduit component 2 comprises a cooling channel 2.1 and a low-temperature heater 2.2, the cooling conduit component 2.1 is arranged on the outer side of the injection conduit component 2.1.1, the cooling conduit component 2.1 is communicated with the injection conduit component 3.3.1.1 and is arranged on the outer side of the injection conduit component 3, the injection conduit 2.1.1.1 is guaranteed to be in a fluid state, the cooling conduit component 3.3 is arranged on the outer side of the injection conduit component 3.1.1 and is used for guaranteeing the injection flow rate, and the injection conduit 3.3 is arranged on the cooling conduit component is arranged on the outer side of the cooling conduit component 3.3 and 3.3.
The end of the material melting screw 1.2 far away from the cooling duct assembly 2 is provided with a hydraulic cylinder for driving the material melting screw 1.2 to axially move and a motor for driving the material melting screw 1.2 to rotate.
The injection screw 3.2 comprises a screw portion 3.2.1 and a piston portion 3.2.2, the piston portion 3.2.2 is in movable sealing fit with the injection channel 3.1, the screw portion 3.2.1 is arranged between the piston portion 3.2.2 and the cavity assembly 4, the joint of the cooling channel 2.1 and the injection channel 3.1 is also arranged between the piston portion 3.2.2 and the cavity assembly 4, the injection screw 3.2 simultaneously injects magnesium alloy to the cavity assembly 4 in a rotating and axially moving mode, and a hydraulic cylinder for driving the injection screw 3.2 to axially move and a motor for driving the injection screw 3.2 to rotate are arranged at one end of the injection screw 3.2 far away from the cavity assembly 4.
The injection screw 3.2 comprises a screw part 3.2.1 and a piston part 3.2.2, the piston part 3.2.2 is in movable sealing fit with the injection channel 3.1, the screw part 3.2.1 is arranged between the piston part 3.2.2 and the cavity assembly 4, the joint of the cooling channel 2.1 and the injection channel 3.1 is also arranged between the piston part 3.2.2 and the cavity assembly 4, the injection screw 3.2 simultaneously injects magnesium alloy slurry to the cavity assembly 4 in a rotating and axially moving mode, the outer diameter of the screw part 3.2.1 and the inner wall of the injection channel 3.1 form clearance fit, the clearance fit means that the screw part 3.2.1 and the injection channel 3.1 keep a rotating space of the screw part 3.2.1, but the clearance is small, the flow quantity of the magnesium alloy slurry permeated from the clearance is small, and the screw part 3.2.1 can be pushed into the cavity assembly 3.1 under the condition of not causing abrasion of the screw part 3.2.1 and the injection channel 3.1.
As shown in fig. 1-3, the first-order material component 1 and the second-order shearing and injection component 3 are horizontally arranged, the first-order material component 1 is arranged above the second-order shearing and injection component 3, the cooling duct component 2 is vertically arranged, the cooling channel 2.1 is perpendicular to the injection channel 3.1, a feed inlet 3.1.1 communicated with the cooling channel 2.1 is arranged on the injection channel 3.1, and the feed inlet 3.1.1 is arranged along the rotation tangential direction of the screw part 3.2.1.
The inner diameter of the screw tooth at one end of the screw rod part 3.2.1 close to the piston part 3.2.2 is provided with taper, namely the inner diameter of the screw tooth is increased towards the direction of the piston part 3.2.2, so that the alloy mixed fluid is ensured to flow towards the direction of the cavity assembly 4, and the conditions of flash and permeation are better prevented.
Compared with the traditional injection piston, the piston part 3.2.2 of the invention is shorter, in the traditional injection piston, in order to ensure the injection quantity, the injection piston needs to complete the stroke required by the injection quantity, and the length of the stroke needs to ensure that the piston part 3.2.2 is connected with the outlet of the cooling duct assembly 2, so that the length of the piston part 3.2.2 needs to be lengthened, and the outlet of the cooling duct assembly 2 is prevented from being directly connected with the injection rear end of the piston part 3.2.2, thereby causing magnesium alloy slurry to directly flow to the injection rear end of the piston part 3.2.2 and influencing the use safety of equipment. The injection front end of the injection screw rod disclosed by the invention adopts the structure of the screw rod part 3.2.1, the injection length of the injection screw rod 3.2 can be realized by utilizing the structure of the screw rod part 3.2.1, and magnesium alloy slurry directly flows into the screw rod part 3.2.1 and is injected forward, so that the piston part 3.2.2 does not need to be designed for a long distance, only the outlet of the cooling conduit assembly 2 is required to be ensured to be arranged at the injection front end of the piston part 3.2.2, and meanwhile, the matching length between the piston part 3.2.2 and the injection channel 3.1 is also reduced, and the abrasion length is reduced.
As shown in fig. 1, the connection part between the injection channel 3.1 and the cavity component 4 is provided with a reducing hole, the reducing hole is tapered, the diameter of the reducing hole is reduced from the injection screw 3.2 to the cavity component 4, a buffer through hole is further arranged between the reducing hole and the forming cavity, in the process of injecting magnesium alloy slurry, the magnesium alloy slurry is pushed in a screw rotating manner, so that the magnesium alloy slurry always performs self-densification movement, the forming quality of a product is ensured, no bubble is formed in the magnesium alloy slurry, the possibility bubble in the magnesium alloy slurry is discharged by reducing the aperture, the forming quality of the alloy is ensured, and the design of the buffer through hole can stabilize the injection flow of alloy mixed liquid and ensure the uniformity of alloy forming.
As shown in fig. 1 and fig. 4-8, an injection part 3.2.3 is further arranged on the injection screw 3.2, the injection part 3.2.3 is arranged at one end, close to the cavity, of the screw part 3.2.1, a connecting rod 3.2.4 is arranged between the injection part 3.2.3 and the screw part 3.2.1, a non-return ring 5 is movably sleeved on the connecting rod 3.2.4, the outer diameter of the connecting rod 3.2.4 is matched with the inner diameter of the non-return ring 5, a plurality of material passing grooves 3.2.5 for passing materials are arranged on the circumference of the connecting rod 3.2.4, a guide groove 3.2.6 which is designed along the axial direction is arranged on the injection part 3.2.3, a guide block 5.1 which is matched with the guide groove 3.2.6 is arranged on the non-return ring 5, a plurality of material passing holes are formed between the injection part 3.2.3.2.3 and the injection part 3.2.3 by abutting against the non-return ring 5.2.3, and the non-return ring 5.2.3 is further arranged on the non-return ring 5.
The outside of the non-return ring 5 is provided with a sealing ring 5.4, the sealing ring 5.4 is provided with an adjusting gap 5.4.1, two ends of the adjusting gap 5.4.1 are provided with overlapping areas in the radial direction, flash can be prevented, the non-return ring 5 is provided with a mounting groove 5.5 for mounting the sealing ring 5.4, a control hole is arranged in the mounting groove 5.5, the control hole comprises a first control hole 5.6 and a second control hole 5.7, the first control hole 5.6 is arranged at one end, close to the injection head, of the non-return ring 5, the second control hole 5.7 is arranged at one end, far away from the injection head, of the non-return ring 5, the first control hole 5.6 is obliquely arranged from inside to outside from the injection head to the spiral pushing groove, and the second control hole is arranged along the radial direction of the connecting rod 3.2.4.
As shown in fig. 1, the first-stage melting assembly 1 comprises a feeding funnel, and an outlet of the feeding funnel is arranged at one end of the melting screw 1.2 away from the cooling conduit assembly 2.
As shown in fig. 9, a thixotropic molding process of a large-injection-amount spherical crystal magnesium alloy adopts continuous five-stage temperature control, shearing and injection processes to cooperate with each other, so that the magnesium alloy is converted into semi-solid spherical crystals and is molded;
stage 1: melting, namely, adopting a first-order melting assembly 1 to carry out tunnel rapid heating softening on magnesium alloy particles until the magnesium alloy particles are melted to be above a liquidus line, and simultaneously gradually self-densifying under extrusion pushing of a melting screw 1.2 and keeping no air from being involved after liquefaction;
Stage 2: near liquid phase, at the end position of the first-order material component 1, the constant temperature control magnesium alloy is maintained at 10-30 ℃ above the near liquidus for homogenization, so that the alloy structure is converted into a pure liquid phase or an extremely low solid phase state;
stage 3: the short-time low supercooling is realized by adopting a temperature control cooling conduit assembly 2, and the temperature control cooling conduit assembly is connected with the first-order material assembly 1 and is used for providing short-time low supercooling conditions for flowing magnesium melt so as to quickly generate a large amount of semi-solid primary crystals in a near-liquid alloy tissue;
stage 4: semi-solid isothermal spherical crystal transformation adopts a horizontal second-order shearing and injection assembly 3 which is communicated with a temperature control cooling catheter assembly 2 and is used for providing semi-solid isothermal heat treatment and injection screw 3.2 shearing action for low supercooled magnesium alloy, so that solid phase in semi-solid primary crystals in magnesium alloy tissues is penetrated and surrounded by low melting point liquid phase to be refined and fully spheroidized, and is transformed into spherical crystal semi-solid slurry;
stage 5: and (3) performing high-speed injection cooling molding, namely completing injection action of spherical crystal semi-solid slurry with good thixotropic property under high pressure and high speed, and filling the slurry into a cavity assembly 4 for cooling molding to form a densified magnesium alloy product.
In the stage 1, the magnesium alloy adopts the specification of granularity between 0.5 and 5mm, and keeps a dry state, and the magnesium alloy material needs to be selected from the types with a semi-solid process window section above 50 ℃;
In the stage 2, the set temperature of the tail end of the first-order material component 1 is 10-20 ℃ above the liquidus temperature of the magnesium alloy; the rotation speed of the melting screw 1.2 is 100r/min, and the magnesium alloy slurry with a pure liquid phase or extremely low solid phase crystal grain diagram shown in figure 10 is formed;
in the stage 3, the low supercooling condition is 10-30 ℃ below the liquidus temperature of the magnesium alloy, and a large amount of semi-solid primary crystals are rapidly generated in the magnesium alloy slurry under the short-time low supercooling condition, as shown in fig. 11, and the solid phase ratio reaches 40-60%;
in the stage 4, the semi-solid magnesium alloy slurry is uniformly propelled into the second-order shearing and injection assembly 3, and is heated again at a constant temperature, the constant temperature is 5-10 ℃ below the liquidus temperature, the rotating speed of the injection screw 3.2 is 60r/min, at the moment, under the combined action of shearing and semi-solid isothermal heat treatment, the primary solid phase is surrounded by low-melting-point liquid phase penetration to be refined and fully spheroidized, and is converted into equiaxed, uniform and fine spherical crystal semi-solid slurry, and the solid phase rate of the magnesium alloy slurry is 10-30% as shown in fig. 12.
In stage 5, the mold temperature was 280℃and the injection speed was 5m/s.
The invention adopts magnesium alloy raw materials as millimeter-sized particles, including but not limited to AZ91, AM60 and other brands of magnesium alloy, the magnesium alloy is heated to be above a near liquidus line through a first-order material component 1, then a large amount of primary crystals are rapidly generated through a cooling conduit component 2, then the primary crystals are converted into tiny spheroidized spherical crystal semi-solid slurry through a second-order shearing and injection component 3, and finally the spherical crystal semi-solid slurry is injected into a cavity component 4 for cooling molding, so that the large magnesium alloy part is prepared. The product has uniform spherical crystal and less oxide inclusion, and can remarkably improve mechanical property and corrosion property.
Example 1, as shown in fig. 13:
AZ91 magnesium particle raw materials with the size of 1.2mm x4mm are conveyed into a first-order material component 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 605 ℃ under the shearing action of a 100r/min material screw 1.2, the structure is converted into a pure liquid phase, then the magnesium alloy slurry flows into a cooling conduit component 2, a large amount of semi-solid primary crystals are rapidly generated in the magnesium alloy structure under the short-time low supercooling condition at 575 ℃, the solid phase ratio reaches 50%, then the magnesium alloy slurry is pushed into a second-order shearing and injection component 3, the magnesium alloy slurry is converted into equiaxial, uniform and fine spherical crystal slurry under the combined action of semi-solid isothermal heat treatment and shearing at 590 ℃, then the front end of the second-order shearing and injection component 3 is injected into a cavity component 4 with the die temperature of 280 ℃ for cooling molding, and the injection speed is selected to 5m/s, and a high-density high-performance magnesium alloy part is obtained. The forming capability is excellent, the semi-solid crystal grains are fine, spheroidized and uniformly distributed, and the yield strength is 170MPa, the tensile strength is 280MPa, and the elongation is 7%.
Example 2, as shown in fig. 14:
AZ91 magnesium particle raw materials with the size of 1.2mm x4mm are conveyed into a first-order material component 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 605 ℃ under the shearing action of a 100r/min material screw rod 1.2, the tissues are converted into pure liquid phases, then the magnesium alloy slurry flows into a cooling conduit component 2, a large amount of semi-solid primary crystals are rapidly generated in the magnesium alloy tissues under the short-time low supercooling condition of 570 ℃, the solid phase ratio reaches 60%, then the magnesium alloy slurry is pushed into a second-order shearing and injection component 3, the magnesium alloy slurry is converted into equiaxed, uniform and fine spherical crystal slurry under the semi-solid isothermal heat treatment and shearing combined action of 585 ℃, then the magnesium alloy slurry is injected into a cavity component 4 with the die temperature of 280 ℃ from the front end of the second-order shearing and injection component 3 for cooling molding, and the injection speed is selected to be 5m/s, and the high-density high-performance magnesium alloy part is obtained. The molding capability is excellent, the semi-solid crystal grains are fine, spheroidized and uniformly distributed, and the yield strength is 165MPa, the tensile strength is 270MPa, and the elongation is 5.5%.
Example 3, as shown in fig. 15:
AM60 magnesium particle raw materials with the size of 1.2mm x4mm are conveyed into a first-order material component 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 630 ℃ under the shearing action of a 100r/min material screw 1.2, the structure is converted into a pure liquid phase, then the magnesium alloy slurry flows into a cooling conduit component 2, a large amount of semi-solid primary crystals are rapidly generated in the magnesium alloy structure under the short-time low supercooling condition of 590 ℃, the solid phase ratio reaches 60%, then the magnesium alloy slurry is pushed into a second-order shearing and injection component 3, the magnesium alloy slurry is converted into equiaxial, uniform and fine spherical semi-solid crystal slurry under the combined action of semi-solid isothermal heat treatment and shearing at 615 ℃, then the front end of the second-order shearing and injection component 3 is injected into a cavity component 4 with the die temperature of 250 ℃ for cooling molding, and the injection speed is selected to 5m/s, and the high-density high-performance magnesium alloy part is obtained. The semi-solid crystal grains are fine, fully spheroidized and uniformly distributed, and the yield strength is 140MPa, the tensile strength is 300MPa, and the elongation is 15%.
Example 4, as shown in figure 16,
AM60 magnesium particle raw materials with the size of 1.2mm x4mm are conveyed into a first-order material component 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 630 ℃ under the shearing action of a 100r/min material screw 1.2, the structure is converted into a pure liquid phase, then the magnesium alloy slurry flows into a cooling conduit component 2, a large amount of semi-solid primary crystals are rapidly generated in the magnesium alloy structure under the short-time low supercooling condition of 602 ℃, the solid phase ratio reaches 40%, then the magnesium alloy slurry is pushed into a second-order shearing and injection component 3, the magnesium alloy slurry is converted into equiaxial, uniform and fine spherical semi-solid crystal slurry under the combined action of semi-solid isothermal heat treatment and shearing at 620 ℃, then the front end of the second-order shearing and injection component 3 is injected into a cavity component 4 with the die temperature of 250 ℃ for cooling molding, and the injection speed is selected to be 5m/s, and a high-density high-performance magnesium alloy part is obtained. The semi-solid crystal grains are fully spheroidized and uniformly distributed, and reach the yield strength of 144MPa, the tensile strength of 300MPa and the elongation of 12 percent.
Comparative example 1, as shown in fig. 17:
AZ91 magnesium particle raw materials with the size of 1.2mm x4mm are conveyed into a first-order material conversion assembly 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 605 ℃ under the shearing action of a 100r/min material conversion screw rod 1.2, the tissue is converted into a pure liquid phase, then magnesium alloy slurry flows into a cooling conduit assembly 2, the material storage flow is carried out under the non-supercooled condition of 600 ℃, the solid phase ratio reaches 10%, then the magnesium alloy slurry is pushed into a second-order shearing and injection assembly 3, under the combined action of semi-solid isothermal heat treatment and shearing at 590 ℃, then the front end of the second-order shearing and injection assembly 3 is injected into a cavity assembly 4 with the die temperature of 280 ℃ for cooling molding, and the injection speed is 5m/s, so that a magnesium alloy part is obtained. It can be seen that coarse semi-solid dendrite structures still exist, so that the matrix is broken and is easy to be broken, the yield strength is 155MPa, the tensile strength is 230MPa, and the elongation is 3%.
Comparative example 2, as shown in fig. 18:
AZ91 magnesium particle raw materials with the size of 1.2mm x4mm are adopted and conveyed into a first-order material component 1 by a feeding hopper, magnesium alloy particles are pushed forward, compressed and rapidly heated to 585 ℃ under the shearing action of a 100r/min material screw 1.2, the magnesium alloy particles are semi-solid tissues below liquidus, then the magnesium alloy slurry flows into a cooling conduit component 2, semi-solid primary crystals are generated in the magnesium alloy slurry under the short-time low supercooling condition at 575 ℃, the solid phase ratio reaches 50%, then the magnesium alloy slurry is pushed into a second-order shearing and injection component 3, under the combined action of semi-solid isothermal heat treatment and shearing at 590 ℃, then the front end of the second-order shearing and injection component 3 is injected into a cavity component 4 with the mold temperature of 280 ℃ for cooling molding, and the injection speed is selected to be 5m/s, and the magnesium alloy part is obtained. It can be seen that coarse semi-solid dendrite structures still exist, so that the matrix is cracked and easily generates stress concentration when being deformed under stress, the yield strength is 150MPa, the tensile strength is 225MPa, and the elongation is 2.8%.
TABLE 1
The foregoing is illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof is allowed to vary. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (10)
1. A thixotropic molding process of a large-injection spherical magnesium alloy is characterized in that: adopting the cooperation of continuous five-stage temperature control, shearing and injection processes to promote the magnesium alloy to be converted into semi-solid spherical crystals and molding;
stage 1: melting, namely, adopting a first-order material melting assembly (1), carrying out tunnel rapid heating softening on magnesium alloy particles until the magnesium alloy particles are melted to be above a liquidus line, and simultaneously gradually self-densifying under extrusion pushing of a material melting screw (1.2) and keeping no air in after liquefaction;
stage 2: near liquid phase, at the end position of the first-order material component (1), the constant temperature control magnesium alloy is maintained at 10-30 ℃ above the near liquidus for homogenization, so that the alloy structure is converted into a pure liquid phase or an extremely low solid phase state;
stage 3: the short-time low supercooling is realized by adopting a temperature control cooling conduit assembly (2) which is connected with the first-order material assembly (1) and is used for providing short-time low supercooling conditions for flowing magnesium melt so as to quickly generate a large amount of semi-solid primary crystals in a near-liquid phase alloy structure;
Stage 4: semi-solid isothermal spherical crystal transformation, which adopts a horizontal second-order shearing and injection assembly (3) to be communicated with a temperature-control cooling catheter assembly (2) and is used for providing semi-solid isothermal heat treatment and injection screw (3.2) shearing action for low-supercooling magnesium alloy, so that solid phase in semi-solid primary crystal in magnesium alloy tissue is surrounded by low-melting point liquid phase penetration to be refined and fully spheroidized, and is transformed into spherical crystal semi-solid slurry;
stage 5: and (3) performing high-speed injection cooling molding, namely completing injection action of spherical crystal semi-solid slurry with good thixotropic property under high pressure and high speed, filling the spherical crystal semi-solid slurry into a cavity assembly (4), and performing cooling molding to form a densified magnesium alloy product.
2. The thixoforming process for a high injection quantity spherical magnesium alloy according to claim 1, wherein the process is characterized by comprising the following steps: in the stage 1, the magnesium alloy adopts the specification of granularity between 0.5 and 5mm, and keeps a dry state, and the magnesium alloy material needs to be selected from the types with a semi-solid process window section of more than 50 ℃.
3. The thixoforming process for a high injection quantity spherical magnesium alloy according to claim 2, wherein the process is characterized by:
in the stage 2, the set temperature of the tail end of the first-order material component (1) is 10-20 ℃ above the liquidus temperature of the magnesium alloy; the rotating speed of the material melting screw (1.2) is 100r/min;
In the stage 3, the low supercooling condition is 10-30 ℃ below the liquidus temperature of the magnesium alloy;
in the stage 4, the constant temperature set temperature of the second-order shearing and injection assembly (3) is 5-10 ℃ below the liquidus temperature, and the corresponding slurry solid phase rate is 10-30%; the rotating speed of the injection screw (3.2) is 60r/min;
in stage 5, the mold temperature was 280℃and the injection speed was 5m/s.
4. A large injection amount spherical crystal magnesium alloy thixotropic molding device is characterized in that: the thixotropic molding process for performing the large injection quantity spherical magnesium alloy according to any one of claims 1 to 3, comprising a first-order material melting assembly (1), a cooling conduit assembly (2), a second-order shearing and injection assembly (3) and a cavity assembly (4), wherein magnesium alloy sequentially passes through the first-order material melting assembly (1), the cooling conduit assembly (2), the second-order shearing and injection assembly (3) and the cavity assembly (4) to finish product production, the first-order material melting assembly (1) comprises a material melting channel (1.1), a material melting screw (1.2) and a material melting heater (1.3), the material melting screw (1.2) is arranged on the axis of the material melting channel (1.1) and is used for pushing self-compacting liquid magnesium alloy and exhaust air, the material melting screw (1.2) simultaneously pushes the magnesium alloy in the direction of the cooling conduit assembly (2) in a rotating and axial moving mode, the material melting heater (1.3) is arranged on the outer side of the material melting channel (1.1) and is used for heating the material melting channel (1.1), the material melting channel (1.1) is kept at the temperature of the material melting channel (1.1) is kept at the low temperature of the magnesium alloy melting channel (2.1) and the cooling conduit assembly (2.1) is kept at the low temperature, the low temperature is communicated with the cooling conduit assembly (2.2.1) is used for performing the cooling operation, and the low temperature (2.1) is connected with the cooling conduit assembly (2.2.2), the injection molding machine is characterized in that the first-order material component (1) is arranged above the second-order shearing and injection component (3), the cooling conduit component (2) is arranged vertically, the second-order shearing and injection component (3) comprises an injection channel (3.1), an injection screw (3.2) and an injection heater (3.3), the injection channel (3.1) is communicated with the cooling channel (2.1), the injection screw (3.2) is arranged on the axis of the injection channel (3.1) and used for injecting magnesium alloy into the cavity component (4), and the injection heater (3.3) is used for heating the injection channel (3.1) to ensure the solid phase rate of magnesium alloy slurry and ensure the smoothness of injection.
5. The large injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 4, wherein: injection screw rod (3.2) include screw rod portion (3.2.1) and piston portion (3.2.2), piston portion (3.2.2) remove sealed cooperation with injection channel (3.1), screw rod portion (3.2.1) are located between piston portion (3.2.2) and die cavity subassembly (4), the junction of cooling channel (2.1) and injection channel (3.1) also locates between piston portion (3.2.2) and die cavity subassembly (4), injection screw rod (3.2) are simultaneously with rotation and follow axial displacement's mode with magnesium alloy to die cavity subassembly (4) direction injection.
6. The large injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 5, wherein: the cooling channel (2.1) is perpendicular to the injection channel (3.1), a feeding port (3.1.1) communicated with the cooling channel (2.1) is arranged on the injection channel (3.1), and the feeding port (3.1.1) is arranged along the rotation tangential direction of the screw rod part (3.2.1).
7. The large injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 4, wherein: injection portion (3.2.3) still is equipped with on injection screw rod (3.2), the one end that screw rod portion (3.2.1) is close to the die cavity is located to injection portion (3.2.3), be equipped with connecting rod (3.2.4) between injection portion (3.2.3) and screw rod portion (3.2.1), the last non-return ring (5) that has cup jointed of removal of connecting rod (3.2.4), the external diameter of connecting rod (3.2.4) agrees with the internal diameter of non-return ring (5), the circumference of connecting rod (3.2.4) is equipped with a plurality of material passing grooves (3.2.5) that are used for the material that pass through.
8. The large injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 7, wherein: be equipped with guide slot (3.2.6) along axial design on injection portion (3.2.3), be equipped with on non return ring (5) with guide slot (3.2.6) matched with guide block (5.1), still be equipped with on non return ring (5) with guide block (5.1) syntropy setting support piece (5.2), support piece (5.2) and injection portion (3.2.3) and support and make injection portion (3.2.3) and non return ring (5) between form material mouth (5.3), still be equipped with a plurality of material holes (3.2.7) on injection portion (3.2.3).
9. The large injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 7, wherein: the outer side of the non-return ring (5) is provided with a sealing ring (5.4), the sealing ring (5.4) is provided with an adjusting gap (5.4.1), the non-return ring (5) is provided with a mounting groove (5.5) for mounting the sealing ring (5.4), and a control hole is arranged in the mounting groove (5.5).
10. The high injection quantity spherical magnesium alloy thixotropic molding apparatus according to claim 9, wherein: the control hole comprises a first control hole (5.6) and a second control hole (5.7), the first control hole (5.6) is arranged at one end of the non-return ring (5) close to the injection head, the second control hole (5.7) is arranged at one end of the non-return ring (5) far away from the injection head, the first control hole (5.6) is arranged from inside to outside and is inclined from the injection head to the direction of the spiral propulsion groove, and the second control is arranged along the radial direction of the connecting rod (3.2.4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310618380.4A CN116727630A (en) | 2023-05-29 | 2023-05-29 | Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310618380.4A CN116727630A (en) | 2023-05-29 | 2023-05-29 | Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116727630A true CN116727630A (en) | 2023-09-12 |
Family
ID=87908923
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310618380.4A Pending CN116727630A (en) | 2023-05-29 | 2023-05-29 | Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116727630A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117259711A (en) * | 2023-10-13 | 2023-12-22 | 伯乐智能装备股份有限公司 | Forming process and device for preparing heterogeneous semi-solid structure magnesium alloy |
-
2023
- 2023-05-29 CN CN202310618380.4A patent/CN116727630A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117259711A (en) * | 2023-10-13 | 2023-12-22 | 伯乐智能装备股份有限公司 | Forming process and device for preparing heterogeneous semi-solid structure magnesium alloy |
| CN117259711B (en) * | 2023-10-13 | 2024-06-11 | 伯乐智能装备股份有限公司 | Forming process for preparing heterogeneous semi-solid structure magnesium alloy |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN116727630A (en) | Thixotropic molding process and equipment for spherical magnesium alloy with large injection quantity | |
| AU622531B2 (en) | Method and apparatus for the injection molding of metal alloys | |
| JP3475707B2 (en) | Method and apparatus for semi-solid injection molding of metal | |
| JP2002514136A (en) | Alloy injection molding equipment: Sub-ring concept | |
| AU7031400A (en) | Method and apparatus for producing semisolid metal slurries and shaped components | |
| CN111390139B (en) | Semi-solid forming equipment and process for non-ferrous metal particles | |
| CN105945255A (en) | Thin-wall part die casting mold and die casting molding equipment | |
| CN116618601B (en) | High-efficiency double-order double-injection light alloy mixed forming device and process | |
| CN101081408A (en) | Method for preparation of alloy extrudate | |
| CN211661060U (en) | Semi-solid forming equipment for aluminum-magnesium-zinc non-ferrous metal particles | |
| CN108672673A (en) | A kind of double punch injection structures of die casting machine | |
| CN1342531A (en) | Technology and die' set for manufacturing seamless Al-alloy tube | |
| CN113579196A (en) | Method for manufacturing light alloy modified product | |
| CN109013728A (en) | A kind of solid-liquid mixes the continuously extruded method and device for preparing high alloy material | |
| CN113388752A (en) | Preparation method of metal-based composite material | |
| CN202725998U (en) | Semi-continuous casting mold for aluminum alloy hollow ingot | |
| CN201380282Y (en) | Semi-solid magnesium alloy injection molding device | |
| CN117259711B (en) | Forming process for preparing heterogeneous semi-solid structure magnesium alloy | |
| CN208728649U (en) | A kind of double formed punch injection structures of die casting machine | |
| CN219786508U (en) | Integrated semi-solid forming equipment for continuously preparing magnesium-based composite material | |
| CN219786523U (en) | Light alloy mixing and forming equipment | |
| CN102784898B (en) | Local pressurization mechanism and method for producing automobile engine suspension shock insulators by same | |
| CN113399642B (en) | Die-casting method for uniform acceleration pressure chamber inoculation semi-solid rheology | |
| CN210334302U (en) | Semi-solid metal cavity inner forming die | |
| CN219561355U (en) | High-efficiency double-order double-injection light alloy mixing and forming device |
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 |