CN103341612B - Swing stirring device for preparing semisolid slurry and rheoforming equipment - Google Patents

Abstract

The invention provides a swing stirring device for preparing semisolid slurry and rheoforming equipment, and belongs to the field of semisolid metal processing technology. The swing stirring device for preparing the semisolid slurry is composed of swing lifting rods, a swing power device, an alloy melt, fixed stirring rods, a supporting frame, a pony ladle, a stirring chamber, a small sprue, a crucible, heating elements, a die-casting machine, a pressing chamber of the die-casting machine, the semisolid slurry, an injection punch, an extruding machine, a pressing chamber of the extruding machine, an extruding punch and the like. Based on the principles of cooling and stirring, the alloy melt flows in the stirring chamber under the action of the swing stirring rods, the nucleation of the alloy melt is promoted to prepare the semisolid slurry under the stirring action of the fixed stirring rods, and the rheoforming equipment achieves rheoforming easily when matched with forming equipment, such as the die-casting machine, the extruding machine or a forging machine. The swing stirring device for preparing the semisolid slurry and the rheoforming equipment are simple in structure, small in investment, low in production cost, stable and reliable in continuous preparation work, and quite suitable for preparation and forming production of the semisolid metal slurry or blank.

Description

A swinging stirring device for preparing semi-solid slurry and rheological shaping equipment

technical field

The invention belongs to the technical field of semi-solid metal processing, and in particular provides a swing stirring device for preparing semi-solid slurry and rheological deformation equipment.

Background technique

Since the early 1970s, researchers such as M C Flemings of the Massachusetts Institute of Technology created the concept of metal semi-solid forming, and the preparation and forming technology of semi-solid metal paste has attracted widespread attention from all over the world as a new technology. . According to the literature "Behavior of metal alloys in the semisolid state" (M C Flemings, Metall Trans, 1991, 22A:957-981), "a suspension cone type semi-solid metal slurry preparation and delivery device" (Kang Yonglin, Chinese patent, 200810114097.3, 2008) and "Theory and Technology of Semi-solid Processing of Metal Materials" (monograph: Kang Yonglin, Mao Weimin, Hu Zhuangqi, Science Press, 2004) report that there are many methods to obtain semi-solid metal slurry, such as mechanical stirring method , electromagnetic stirring method, strain-induced melt activation method, grain refinement and remelting method, turbulence effect method, single-screw stirring method, double-screw stirring method, low superheat inclined plate casting method, melt mixing method, Bubble stirring method, etc. Similarly, the above-mentioned literatures have also proposed many rheological deformation methods of semi-solid metal slurries, such as traditional mechanical agitation rheological deformation, injection chamber preparation slurry rheological deformation, single-screw mechanical agitation rheological deformation , double-helix mechanical agitation rheological deformation, low superheat inclined plate casting rheological deformation, CRP (Continuous Rheoconversion process) rheological deformation, SEED (Swirled Enthalpy Equilibation Device) rheological deformation, etc. However, in order to reduce the preparation and forming costs of semi-solid metal pastes, scholars, experts and industrial circles from all over the world are still working hard to propose new preparation technologies for semi-solid metal pastes or blanks.

The literature "semi-solid processing of engineering alloys by a twin-screw rheomolding process." (S Ji, Z Fan and M J Bevis, Mater Sci & Eng, 2001, 299A: 210-217) proposed: Twin-screw mechanical agitation rheology The injection casting equipment mainly includes a liquid magnesium alloy feeding mechanism, a double-helix mechanical stirring mechanism, an injection mechanism and a central control mechanism. In the double-helix mechanical stirring rheological injection casting equipment, there is generally no swing stirring device for semi-solid slurry preparation, and it is only necessary to smoothly introduce the superheated alloy melt into the double-helix mechanical stirring barrel. The feeding mechanism can ensure that the liquid magnesium alloy with the right temperature and quantity is supplied to the double-helix mechanical stirring mechanism; once the liquid magnesium alloy enters the stirring system, it is generally sheared strongly by the double-helix mixing barrel, while being rapidly cooled to the expected solid phase Score; when the semi-solid magnesium alloy slurry reaches the delivery valve, the primary solid phase has transformed into spherical particles and is evenly distributed in the liquid phase with a low melting point; when the delivery valve is opened, the semi-solid magnesium alloy slurry enters the pressure chamber, It is pressed into the mold cavity and completely solidifies in the mold to form a mechanical part. But this double-helix mechanically stirred rheological injection casting equipment is only suitable for semi-solid rheological forming of magnesium alloys.

Chinese patent 200810114097.3 proposes a suspended cone type semi-solid metal slurry preparation device, which uses a pouring spoon or a feeding device to pour liquid metal into the slurry making device. The shearing and stirring effect of the semi-solid slurry finally prepares a fine and round semi-solid slurry; in the semi-solid slurry equipment, generally there is no swing stirring device for the preparation of the semi-solid slurry, only the superheated metal liquid is poured Just put it in the cone.

European patent EP 0745691A1 proposes New Rheocasting technology, referred to as NRC. In the summary of NRC technology, firstly reduce the superheat of the pouring molten metal, direct the molten metal to an inclined flat plate (or inclined circular tube, or inclined semicircular tube), and the molten metal flows into the crucible of the machine, and then it is properly cooled and solidified. Yes, the temperature of the metal slurry in the semi-solid metal melt is adjusted to obtain a temperature field or solid phase fraction as uniform as possible, and finally a semi-solid metal slurry is obtained, and then the semi-solid metal is rewarded for rheological die-casting or forging , can form various other beings. In the equipment of the New Rheocasting process, there is generally no swing stirring device for semi-solid slurry preparation, and it is only necessary to pour the superheated metal melt onto the inclined flat plate (inclined circular tube or inclined semicircular tube) smoothly.

Chinese patent 200710176136.8 proposes a semi-solid metal slurry preparation and rheological shaping equipment, which pours superheated melt into an oblique straight composite pipe channel composed of inclined pipe and vertical pipe to pour molten metal, and promotes the molten metal Cooling and nucleation, preparation of semi-solid metal slurries and rheological shaping. In the equipment of this technology, there is generally no swing stirring device for semi-solid slurry preparation, and it only needs to pour the superheated metal melt into the inclined sprue.

In addition, there is a melt dispersion mixing pulping device (patent: 200620018003.9); unequal diameter bend extrusion-shear-induced isothermal spheroidal crystallization semi-solid billet compound preparation method (patent: 03132471.1); shear low-temperature casting semi-solid Slurry preparation device (patent: 200810107252.9); low superheat plus weak electromagnetic stirring pulping technology (patent: 00109540.74); wave-type inclined version vibration pulping device (patent: 200710011510.9); a light alloy semi-solid slurry preparation device (patent 201120425807.1) and so on. In the equipment of the above technologies, there is no special swing stirring device for preparing semi-solid slurries of light alloys such as magnesium and aluminum, that is, the swing stirring device is not used to cool and stir the alloy melt to promote nucleation.

The above various devices and methods for preparing semi-solid alloy slurry have their own characteristics, but they also have their own shortcomings. Most of them are still in the laboratory research stage, and new slurrying devices and technologies still need to be proposed so that Simplify the process, reduce the cost, and gradually promote the industrial application of semi-solid metal processing technology.

Contents of the invention

The purpose of the present invention is to provide a semi-solid slurry preparation and rheological deformation equipment. The device uses the principle of cooling and stirring. The alloy melt flows in the mixing chamber due to the action of the swing lifting rod, and is stirred by the fixed stirring rod to promote the nucleation of the alloy melt. After the semi-solid slurry is prepared, it flows from the gate flow out. This equipment can easily realize rheological forming with forming equipment such as die-casting machine, extrusion machine or forging machine.

The technical solution of the present invention is: a swing stirring device for preparing semi-solid slurry and rheological forming equipment, which consists of a swing lifting rod, an alloy melt, a fixed stirring rod, a bracket, a pouring spoon, a mixing chamber, a small gate, and a crucible , heating element, die-casting machine and pressure chamber, semi-solid slurry, injection punch, extruder, pressure chamber and extrusion punch; the swing lifting rod is connected to the wall of the mixing chamber, and the fixed stirring rod The support is connected to the stirring chamber, and the crucible is combined with the heating element; the swing stirring device composed of a swing lifting rod, a fixed stirring rod, a support, a stirring chamber, a small gate and a stirring power device is combined with a die-casting machine and a pressure chamber to realize rheological die-casting ; The swing stirring device is composed of a swing lifting rod, a fixed stirring rod, a bracket, a stirring chamber, a small gate and a stirring power device. The swing stirring device is combined with an extruder and a pressure chamber to realize rheological extrusion.

The semi-solid slurry swing stirring device can be directly combined with the die-casting machine and the pressure chamber 10 to realize rheological die-casting. After the prepared semi-solid slurry 11 enters the die-casting machine and the pressure chamber 10, the injection punch 12 moves the semi-solid slurry according to the process parameters. The solid slurry 11 is pressed into the mold cavity for filling to obtain semi-solid product parts; at the same time, the preparation crucible 8 can also be combined with the die-casting machine and the pressure chamber 10, and the semi-solid slurry 11 in the preparation crucible 8 is poured into the die-casting machine to press After the chamber 10, the injection punch 12 presses the semi-solid slurry 11 into the cavity for filling.

The semi-solid slurry swing stirring device can be directly combined with the extruder and the pressure chamber 13 to realize rheological extrusion forming. After the prepared semi-solid slurry 11 enters the extruder and the pressure chamber 13, the extrusion punch 14 Parameters Press the semi-solid slurry 11 into the mold cavity for filling to obtain semi-solid extruded parts; at the same time, the preparation crucible 8 can also be combined with the extruder and the pressure chamber 13 to prepare the semi-solid slurry 11 in the preparation crucible 8 After being poured into the press chamber 13 of the extruder, the extruding punch 14 presses the semi-solid slurry 11 into the cavity for filling.

The structure of the swing stirring device is shown in Fig. 1 and Fig. 2. The swing lifting rod 1 is symmetrically distributed on both sides of the mixing chamber 6, and the lower end is connected with a swing power device, and the methods include but are not limited to circular, reciprocating, and swinging. The symmetrically distributed swing lifting rod 1 makes the stirring chamber 6 swing back and forth to make the alloy melt flow. The frequency of swing is 10~120 times/minute. The fixed stirring rod 3 is fixed inside the stirring chamber 6, and the stirring rod is composed of a certain number of cylinders of equal height, and the height of the cylinders is 100-1000mm, and the bottom of the cylinder is 10-200mm away from the bottom of the stirring chamber 6. The shape of the cross-section of the cylinder includes, but is not limited to, circle, square, triangle, and ellipse. The material of the cylinder includes but not limited to steel, ceramics, graphite, copper. The material of stirring chamber 6 includes but not limited to steel, graphite, pottery, copper; The internal shape of stirring chamber 6 includes but not limited to semicircle, semiellipse, rectangle, triangle; ~2mm; or the inner wall of the stirring chamber 6 is equipped with anti-corrosion and anti-stick lining; the temperature range of the metal melt 2 is the metal liquidus temperature -50°~200°; the temperature of the stirring chamber 6 and the fixed stirring rod 3 is low at the solidus temperature of the metal melt.

The advantage of the present invention is that: the molten metal with a degree of superheat of -50°C to 200°C is poured into the stirring chamber, and the superheated metal is cooled by the wall of the vessel and the stirring rod, and at the same time, under the action of the swing, the molten metal is in the stirring chamber Generate flow and stirring, promote the nucleation of alloy melt, prepare semi-solid slurry, and flow out from the small gate after the slurry is prepared. This equipment can easily realize rheological forming with forming equipment such as die-casting machine, extrusion machine or forging machine. .

This equipment cancels the complicated electromagnetic stirring or mechanical stirring device, also cancels the complicated low superheat pouring, and also greatly reduces the difficulty of liquidus pouring, greatly reduces the energy consumption of preparation, and can also obtain excellent semi-solid metal slurry material, significantly reducing the preparation cost of the semi-solid metal slurry. The structure of the equipment is simple, the investment is small, and the production cost of castings, extrusions or forgings is low, which is very suitable for the rheological deformation of semi-solid metals and the production of billets.

Description of drawings

Figure 1 is a schematic diagram of the preparation of light alloy semi-solid slurry by a rocking stirring device.

Figure 2 is a side view of the rocking stirring device.

Figure 3 is a schematic diagram of the combination of the rocking stirring device and the die casting machine.

Fig. 4 is a schematic diagram of the combination of the oscillating stirring device and the extruder.

In the figure: 1 swing lifting rod, 2 alloy melt, 3 fixed stirring rod, 4 bracket, 5 pouring spoon, 6 mixing chamber, 7 small gate, 8 crucible, 9 heating element, 10 die casting machine and pressure chamber, 11 half Solid slurry, 12 injection punches, 13 extruder and press chamber, 14 extrusion punches.

detailed description

The structure and implementation effects of the present invention will be further described below in conjunction with examples.

As shown in Fig. 1, a kind of rocking stirring device of the present invention prepares semi-solid slurry and rheological shaping equipment, and this equipment is made up of rocking lifting rod 1, fixed stirring rod 3, support 4, ladle 5, stirring chamber 6 and small Stirring device composed of gate 7, crucible 8, heating element 9, die-casting machine, pressure chamber 10 and injection punch 12 constitute rheological die-casting forming equipment and extrusion machine, pressure chamber 13 and extrusion punch 14. Variable extrusion molding equipment;

Wherein, the swing connecting rod 1 is symmetrically distributed on both sides of the stirring chamber 6, the upper end of the swing connecting rod 1 is fixedly connected to the outer wall of the stirring chamber 6, and the lower end of the swing connecting rod 1 is connected to the swing power. The device is fixed, the swing power device 15 drives the stirring chamber 6 to perform circular, reciprocating or swinging motion through the swing connecting rod 1, and the fixed stirring rod 3 is arranged at the center of the stirring chamber 6 , is fixedly connected to the stirring chamber 6 through the support 4 , and a small gate 7 is provided on one side of the stirring chamber 6 .

Example 1:

(1) The liquidus line of the ZL101A aluminum alloy used in the test is 615°C. Melt the alloy in a crucible resistance furnace. When the temperature of the alloy reaches about 720°C, use a bell jar to press the dried hexachloroethane into the melt The lower part (the addition amount is 0.5% of the total weight of the alloy liquid) is gently shaken to carry out the degassing and slag removal refining treatment of the alloy melt, and finally the temperature of the alloy melt is lowered to 630°C for heat preservation.

(2) Set the temperature of the mixing chamber and stirring rod of the swing stirring device of the device of the present invention to 200°C, and the swing frequency to 30 times/minute, and pour the alloy melt smelted in the previous step into the swing stirring device with a ladle 5 In the stirring chamber 6, driven by the swing power device, the stirring chamber 6 is swayed by the swinging lifting rod 1 on both sides, and the swaying of the stirring chamber 6 drives the alloy melt in the stirring chamber to move, and at the same time, it is fixed by the bracket 4 The fixed stirring rod 3 has a stirring effect on the melt. The overheated melt is cooled by the wall and the fixed stirring rod 3. At the same time, under the action of the swing, the melt flows and stirs in the mixing chamber to promote the alloy melt. For nucleation, the slurry is prepared and flows into the crucible 8 from the small gate 7. The temperature of the slurry is in the semi-solid range, and a certain proportion of spherical primary solid phases are evenly distributed in the liquid phase collective.

Example 2:

(1) The liquidus temperature of the A356 aluminum alloy used in the test is 615°C. The aluminum alloy ingot is put into a crucible resistance furnace with a preheating temperature of 400°C. After the temperature of the alloy liquid reaches 700°C, it is refined. Press the dried hexachloroethane into the lower part of the melt (the amount added is 0.5% of the total weight of the alloy liquid), and shake it gently to degas the alloy melt, remove slag and refine it, and finally melt the alloy Body temperature drops to 640°C for heat preservation.

(2) Set the temperature of the stirring chamber and the stirring rod of the swing stirring device of the device of the present invention to 250°C, and the swing frequency is 60 times/minute, and pour the alloy melt 2 smelted in the previous step into the stirring chamber of the swing stirring device 6, the superheated metal is cooled by the wall and the fixed stirring rod 3, and at the same time, under the action of swing, the melt flows and stirs in the stirring chamber 6, which promotes the nucleation of the alloy melt 2, and the semi-solid slurry After the material is prepared, it flows directly into the die-casting machine and the pressure chamber 10 from the small gate 7, and is carried out through the injection punch 12 for rheological die-casting.

Claims (4)

1. A swing stirring device for preparing semi-solid slurry and rheological forming equipment, characterized in that it consists of a swing lifting rod (1), alloy melt (2), fixed stirring rod (3), bracket (4), pouring Spoon (5), mixing chamber (6), small sprue (7), crucible (8), heating element (9), die-casting machine and pressure chamber (10), semi-solid slurry (11), injection punch (12), an extruder, a pressure chamber (13) and an extrusion punch (14); the swing lifting rod (1) is connected to the outer wall of the mixing chamber (6), and the fixed stirring rod (3) passes through The support (4) is connected with the stirring chamber (6), and the crucible (8) is combined with the heating element (9); the stirring rod (3), support (4), stirring chamber (6), The swing stirring device composed of the small gate (7) and the stirring power device is combined with the die casting machine and the pressure chamber (10) to realize rheological die casting; the swing lifting rod (1), the fixed stirring rod (3), the bracket (4), The swing stirring device composed of the stirring chamber (6), the small gate (7) and the stirring power device The swing stirring device is combined with the extruder and the pressure chamber (13) to realize rheological extrusion. 2. The semi-solid slurry and rheological forming equipment prepared by the swing stirring device according to claim 1, characterized in that: the swing lifting rod (1) makes the stirring chamber swing back and forth to make the alloy melt flow; the swing lifting rod ( 1) Symmetrically distributed on both sides of the mixing chamber (6), the lower end is connected with a swing power device, and the methods include circular, reciprocating or swing; the frequency of swing is 10~120 times/min. 3. The semi-solid slurry and rheological shaping equipment prepared by the rocking stirring device according to claim 1, characterized in that: the fixed stirring rod (3) is composed of a certain number of columns of equal height, and the columns The height is 100~1000mm, and the bottom of the cylinder is 10~200mm away from the bottom of the mixing chamber (6); the shape of the cross section of the cylinder is circular, square, triangular or elliptical; the material of the cylinder is steel, ceramics, graphite or copper . 4. Preparation of semi-solid slurry and rheological shaping equipment according to claim 1 or 2, characterized in that: the material of the stirring chamber (6) is steel, graphite, ceramics or copper; the stirring chamber (6) The cross-sectional shape is semicircle, semiellipse, rectangle or triangle; the inner wall of the mixing chamber (6) is painted with ceramic paint, and the thickness of the ceramic paint is 0.1~2mm; or the inner wall of the mixing chamber (6) is equipped with anti Corrosion and anti-stick lining; the temperature of the stirring chamber (6) and the stationary stirring rod (3) is below the solidus temperature of the metal melt.