The invention belongs to the technical field of aluminum-strontium alloy production, and specifically relates to an aluminum-strontium alloy production process.
As the name suggests, aluminum-strontium alloy is an alloy whose main elements are metal aluminum and metal strontium.Aluminum-strontium alloy profiles include plates, bars, wires, etc..Among them, the production process of aluminum-strontium alloy wire usually includes batching, smelting, casting and extrusion..That is, select suitable elemental aluminum raw materials and elemental strontium raw materials, mix them according to requirements, and then smelt and cast them into aluminum-strontium alloy bars, and finally extrude the aluminum-strontium alloy bars into aluminum-strontium alloy wires.
In the existing production process, extrusion molding usually involves placing the heated and softened aluminum-strontium alloy bar in a bar containing cavity outside the forming die, as shown in Figure 1, the forming die (2) and the bar containing cavity ( 1) Both are straight cylindrical and coaxial. In order to avoid deformation of the aluminum-strontium alloy rod in the radial direction, the radial dimension of the rod-containing cavity (1) is the same as that of the aluminum-strontium alloy rod. The extrusion of the aluminum-strontium alloy bar by the extrusion head makes the aluminum-strontium alloy enter the forming die (2) for extrusion molding, in order to avoid the softened bar from the gap between the extrusion head and the bar containing cavity (1) Extrusion, the radial size of the extrusion head is the same as the radial size of the bar containing cavity (1).
During the extrusion molding operation, the extrusion head is against the end of the aluminum-strontium alloy bar away from the forming die (2), and pressure is applied to the aluminum-strontium alloy bar. The softened aluminum-strontium alloy bar undergoes axial deformation and gradually enters In the cavity of the forming die (2), and extruded from the other end of the forming cavity to form a smaller aluminum-strontium alloy wire.As the wire is extruded, the height of the bar is gradually reduced. When the height of the bar is reduced to a certain level, the extrusion head will press the remaining bar on the end of the forming die (2), and the remaining The lower bar cannot be squeezed into the forming die (2) for forming. Due to the restriction of the bar containing cavity (1), it cannot move outwards and is separated from the wire, and finally left in the extrusion head and forming die (2) In between, it is extruded into a block shape to form wire scrap.If the scrap is not cleaned, the molded wire cannot be demolded, and the scrap is cleaned, on the one hand, the extrusion molding cannot be continuously performed, and the efficiency of the extrusion molding is low. On the other hand, it is molded into a block When the waste material is recycled and reused, it needs to be reheated for smelting, which is troublesome..
Technical realization elements:
The present invention intends to provide an aluminum-strontium alloy production process to solve the technical problems that the existing production process cannot be continuously extruded and has low efficiency.
The aluminum-strontium alloy production process in this scheme includes batching, smelting, casting and extrusion molding, and is characterized in that the extrusion molding is:
Step 1) Set up a residual material cavity between the straight cylindrical molding die and the bar containing cavity. The shape of the residual material cavity is frustum shape, the bottom diameter of the frustum shape is 30mm, and the taper of the cone is 1/3. The remaining material cavity is coaxial with the forming mold, and the bottom surface of the remaining material cavity is close to the forming mold;
Step 2) Put the cast aluminum strontium bar into the remaining material cavity, and extrude the aluminum strontium bar, so that the aluminum strontium bar is extruded into a wire through a forming die, and the remaining height of the bar is 10 -20mm, put in the next bar and continue to squeeze.
The frustum shape refers to the remaining part of the cone after the tip is removed, the bottom surface of the frustum shape refers to the bottom surface of the cone, and the top of the frustum shape refers to the end of the cone opposite to the bottom surface.
The technical principles and technical effects of the aluminum-strontium alloy production process of this program are:
Put the aluminum-strontium alloy bar through the bar containing cavity from the top of the residual material cavity into the residual material cavity, and the extrusion head enters from the bar containing cavity to apply pressure to the aluminum strontium alloy bar, and the residual material cavity Under the action of the extrusion force, the bars in the squeeze into the molding die for extrusion molding.To be bar Tungsten Weight When the remaining height is 10-20mm, put in the next bar and continue to squeeze. Under the extrusion of the next bar, the previous bar continues to enter the molding die for extrusion molding. At the same time, because The bar located in the residual material cavity has a cavity left in the circumferential direction, and the bar will bulge and deform in the circumferential direction. In particular, the end of the previous bar located outside the forming mold will bulge outward and follow the residual material shape. The inner wall of the cavity moves in the direction of the rod accommodating cavity to wrap the next rod and squeeze the next softened rod radially inward, so that the two front and rear rods move in the radial direction. It will be fused together under double extrusion in the axial direction to realize continuous extrusion of the bar..With this extrusion method, the previous bar will not produce excess waste, and it will be extruded continuously with the next bar, thus saving the time for cleaning the excess waste and processing the excess waste..
In the prior art, in order to avoid the inconvenient extrusion of the bar material in the circumferential direction, or to avoid the bar material from being extruded from the feed end, the technicians will always think of using the feed end of the forming die to accommodate and transport aluminum. The size of the cavity of the strontium alloy bar is designed to be the same as that of the aluminum-strontium alloy bar, and the cavity that contains the bar is designed to be a simple straight cylinder. This is the most conventional choice for technicians according to the existing thinking. However, this The shortcoming brought by the design is the generation of excess waste. Even with reference to the technical means in this solution, when the remaining height of the bar is 10-20mm, the next bar is placed, and the two front and rear bars are only on the axis. It will not fuse together under the pressure of the direction. When the previous bar is squeezed to the end, the material on the inner side will enter the forming mold, but due to the small amount of material, it is inconvenient to form a complete wire, while the outer material Since it is not fused with the latter bar, the latter bar can drain it to the inside.Because of the intermolecular force, it will not flow to the inside. Due to the restriction of the inner wall of the bar containing cavity, it will not flow to the outside. Therefore, it can only stay between the next bar and the forming mold to form excess waste. , It affects the demoulding of the previous wire and the extrusion of the next wire. Therefore, after each bar is extruded, the excess waste must be cleaned up, resulting in low production efficiency and troublesome operation.
The following are the preferred solutions based on the above-mentioned basic solutions:
Preferred solution 1: In the step 1), the bottom diameter of the frustum shape is 30mm, the taper of the frustum shape is 1/3, and the height of the frustum shape is 30mm..
Preferred plan two: based on the basic plan or preferred plan one, in the step 2), when the remaining height of the bar is 15mm, put in the next bar to continue extrusion.
Preferred solution three: Based on preferred solution two, the smelting is:
Step 1) Heat the molten aluminum to 771-850��C;
Step 2) Press the strontium ingot into the molten aluminum with a special tool until the strontium ingot is completely melted. The special tool includes a support rod. The lower end of the support rod is provided with a pressure cover, and the wall of the pressure cover is distributed with multiple through holes.In the prior art, strontium ingots are usually directly poured into molten aluminum, and the density of strontium is 2.54*103kg/m3, The density of aluminum is 2.7*103kg/m3, Strontium will float upwards after being put into molten aluminum, contact with air, it will be burnt easily at high temperature.In this solution, a pressure cover is used to press the strontium ingot to the bottom of the molten aluminum. On the one hand, it can prevent the strontium ingot from floating upwards and contacting the air and burning. Easier to dissolve in molten aluminum.Moreover, the strontium ingot reacts violently during the process of melting. The pressure cover is used to press it into the aluminum liquid. Compared with the pressure applied by an independent pressure rod, the strontium ingot will not continuously float upwards. Need to repeatedly apply pressure.There are a number of through holes distributed on the wall of the pressure cover. The through holes can facilitate the circulation of liquid aluminum and liquid strontium and the transfer of heat to facilitate the rapid melting of strontium ingots.
Preferred Option Four: Based on Preferred Option Three, during the smelting process, nitrogen is introduced into the molten aluminum for refining.Nitrogen refining can remove the oxygen in the aluminum liquid, avoid the oxidation of metal aluminum and metal strontium, which affects the alloy performance, and can also avoid the burning loss caused by the presence of oxygen in the aluminum liquid.
Preferred solution five: Based on preferred solution four, the support rod is provided with an air passage communicating with the pressure hood, and nitrogen gas is introduced into the molten aluminum through the air passage.In this way, nitrogen can be introduced into the molten aluminum. At the same time, the nitrogen can be introduced into the pressure hood, which can agitate the liquid in the pressure hood, which facilitates the melting of strontium ingots, and facilitates the circulation of liquid and the transfer of heat.
Preferred solution 6: Based on preferred solution 3 or 4 or 5, during the smelting process, while pressing the strontium ingot into the molten aluminum, a special tool is used to stir the molten aluminum.In order to facilitate the mixing of metal aluminum and metal strontium, and reduce the additional stirring process, the use of special tools in the present invention can skillfully achieve multiple functions at the same time: 1. Press the strontium ingot into the aluminum liquid to avoid the strontium ingot. Burnout; 2. Pour nitrogen into the molten aluminum to refine the molten aluminum. At the same time, it can strengthen the circulation and heat transfer of the liquid and accelerate the melting of the strontium ingot; 3. Stir the liquid to facilitate the mixing of the two metals.
Description of the drawings
Fig. 1 is a schematic diagram of the structure of an extrusion molding die in the prior art;
Figure 2 is a schematic diagram of the structure of the extrusion molding die in the embodiment of the present invention.
The present invention will be further described in detail below through specific implementations:
Aluminum-strontium alloy production process, including four processes of batching, melting, casting and extrusion molding.among them:
Ingredients: select aluminum ingots and strontium ingots, weigh 100kg of strontium ingots and 1000kg of aluminum ingots in a ratio of 1:10, and mix.
Step 1) Put the aluminum ingot into the melting furnace and raise the temperature to melt the aluminum ingot into molten aluminum;
Step 2) Raise the temperature of the molten aluminum to 771-850C, and use special tools to press the strontium ingot into the molten aluminum. The special tools include a support rod. The lower end of the support rod is equipped with a pressure cover. The air passage connected by the hood, and the wall of the pressure hood is evenly distributed with multiple through holes.In the process of pressing the strontium ingot into the molten aluminum to melt the strontium ingot, use a special tool to stir the molten aluminum. At the same time, pass nitrogen into the molten aluminum through the air passage in the support rod for refining until the strontium ingot is completely melted.
Casting: The above-mentioned molten solution is slagged, and after standing for 5 minutes, it is cast into a cylindrical aluminum-strontium alloy bar to be extruded. The bar is 4kg/piece, the diameter of the bar is 20mm, and the height is 400mm; cooling with water.
Step 1). As shown in Figure 2, a residual material cavity 2 is set between the straight cylindrical forming mold 3 and the bar containing cavity 1. The height of the forming mold 3 is 10mm and the diameter is 9.8mm; the shape of the residual material cavity 2 is frustum shape, the bottom diameter of the frustum shape is 30mm, the top diameter is 20mm, the taper of the cone is 1/3, the bottom surface of the residual material cavity 2 is close to the forming mold 3; the forming mold 3 The discharging end of the discharging end is provided with a discharging die 4, the discharging die 4 is frustum-shaped, the bottom diameter of the discharging die 4 is 20mm, and the top diameter is 9.8mm, the height of the output die 4 is 35mm.The bar containing cavity 1, the remaining material cavity 2, the forming mold 3, and the discharging mold 4 are coaxial, and the remaining material cavity 2, the forming mold 3, and the discharging mold 4 are integrally formed.
Step 2) Heat the aluminum-strontium alloy bar to 480-550 C, and put it into the residual material cavity 2 through the bar containing cavity 1, and use the extrusion head to resist the end of the aluminum-strontium alloy bar , Use a 600-ton extruder to extrude the aluminum-strontium alloy bar, so that the aluminum-strontium bar is extruded into a wire through the forming die 3. When the remaining height of the bar is 15mm, put in the next bar to continue extrusion , And so on, to achieve continuous extrusion of aluminum-strontium alloy wire.
Through many experimental observations, when the production process in the embodiment is used to produce aluminum-strontium alloy wire, the strontium ingot will not be burnt, and during the extrusion process, no excess waste will be produced, and there is no need to extrude each one. The bar will treat the leftover waste.