CN113000817A

CN113000817A - Squeeze casting aluminum alloy infiltration mold based on silicon carbide composite material and method thereof

Info

Publication number: CN113000817A
Application number: CN202110203023.2A
Authority: CN
Inventors: 刘剑锋; 杨湛成; 黄长明
Original assignee: Guangzhou Hede Lightweight Forming Technologies Co ltd
Current assignee: Guangzhou Hede Lightweight Forming Technologies Co ltd
Priority date: 2021-02-23
Filing date: 2021-02-23
Publication date: 2021-06-22

Abstract

The invention discloses an infiltration die and method for extrusion casting aluminum alloy of silicon carbide composite material, comprising a movable die core, a fixed die core and a sprue bush, and the infiltration die is characterized in that the movable die core and the fixed die core are respectively provided with three heating rods, aluminum liquid slowly enters a cavity from a material handle of the sprue bush through a flow channel, when mold filling is finished, the speed is switched to pressure, and a punch continuously pressurizes until a product is solidified; the aluminum-based silicon carbide infiltration mold for extrusion casting of the silicon carbide composite material and the aluminum-based silicon carbide infiltration method prepared by the mold are good in mold filling, free of loose air holes, high in yield, low in production cost, good in stability and high in strength.

Description

Squeeze casting aluminum alloy infiltration mold based on silicon carbide composite material and method thereof

Technical Field

The invention relates to the technical field of dies, in particular to an extrusion casting aluminum alloy infiltration die of a silicon carbide composite material and a method thereof.

Background

Silicon carbide fibers are typically ceramic fibers containing carbon and silicon as main components, and have both whisker and continuous fiber shapes. As one of the most important reinforcing materials of the advanced composite material, the composite material has the advantages of high-temperature oxidation resistance, high hardness, high strength, high thermal stability, corrosion resistance, low density and the like. Therefore, the method is concerned in high-tech fields such as aerospace, military weaponry and the like. Because of the characteristics of high hardness and high strength of silicon carbide, pure silicon carbide is very brittle, molten aluminum liquid needs to be pressed into a silicon carbide prefabricated body with micropores, the performance of the silicon carbide prefabricated body exceeds that of tungsten copper and the price of the silicon carbide prefabricated body is far lower than that of the silicon carbide prefabricated body, and the silicon carbide prefabricated body can be made into large-size parts and special-shaped parts which cannot be formed by the tungsten copper.

At present, the preparation of the aluminum-based composite silicon carbide in China mainly comprises powder metallurgy, pressure infiltration, liquid stirring casting methods and the like.

The earliest method for manufacturing the aluminum-based composite silicon carbide in China is powder metallurgy, reinforcing material particles and aluminum alloy powder can be mixed according to any proportion, the mixing uniformity is good, replacement and aggregation are not estimated to occur, and the prepared mechanical property is high. However, the powder metallurgy method has high pollution, complex manufacturing process and equipment and high production cost, and is gradually eliminated.

Domestic pressure infiltration equipment is mainly refitted from low pressure casting equipment, and the refitting shields all advantages of the low pressure casting equipment and ignores the fact that the low pressure casting equipment is not suitable for manufacturing high temperature moulds completely, so that the working stability is poor (gas in a prefabricated part is not easy to be discharged before solidification to cause air holes and loosening), deformation, mold burst and aluminum leakage defects.

The method for producing the aluminum-based composite silicon carbide in an industrial scale in China is mainly a liquid stirring casting method, the SiC particle reinforcement is directly added into molten aluminum alloy, particles are uniformly dispersed in a matrix melt through stirring in a certain mode, and the compounded melt can be cast into ingots, castings and the like for use. Simple process, high production effect and low manufacturing cost. But also has the disadvantages of poor stability, low strength and the like.

Disclosure of Invention

The invention aims to solve the technical problem of providing an extrusion casting aluminum alloy infiltration mold of a silicon carbide composite material and a method thereof.

The technical problem to be solved by the invention is realized by the following technical scheme:

the extrusion casting aluminum alloy infiltration mold for the silicon carbide composite material and the method thereof comprise a movable mold core, a fixed mold core and a sprue bush, and are characterized in that the movable mold core and the fixed mold core are respectively provided with three heating rods, aluminum liquid slowly enters a cavity from a material handle of the sprue bush through a flow channel, the speed is switched to pressure when mold filling is finished, and a punch continuously pressurizes until a product is solidified.

Preferably, the porosity of the silicon carbide preform is 10%, and the balance of 1mm is left around the silicon carbide preform. During filling, the aluminum liquid can wrap the silicon carbide preform so as to achieve the infiltration effect.

Preferably, the working temperature of the mold is 420-430 ℃; the silicon carbide prefabricated body needs to be put into an oven to be baked to 900 ℃, and can be used after more than 1 hour; the working temperature of the aluminum liquid is 730 plus 740 ℃. Ensuring good infiltration effect.

Preferably, after the aluminum-based silicon carbide is cast, the aluminum-based silicon carbide is taken out of the mold, and is placed into a holding furnace within 10-15 seconds, the holding furnace is set at 500 ℃, the temperature is reduced by 100 ℃ per hour, and the aluminum-based silicon carbide is placed at 100 ℃ and is cooled at room temperature. Ensures that the product is not deformed and cracked.

Has the advantages that: after the structure is adopted, under the dual actions of low-speed filling and high-pressure feeding, the aluminum-based silicon carbide has good filling, no loose pores, high yield and lower production cost; the aluminum alloy liquid is pressed into the silicon carbide prefabricated body to form the SiC aluminum matrix composite material which has good stability, density of 1/3 of steel, higher strength than pure aluminum and medium carbon steel, and the advantages of high toughness, high plasticity, high modulus, high hardness and high wear resistance.

Drawings

FIG. 1 is a schematic view of the structure of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and specific examples, which are not intended to limit the invention in any manner.

Example 1

The die for infiltrating the silicon carbide composite material into the aluminum alloy by extrusion casting and the method thereof as shown in figure 1 comprise a movable die core, a fixed die core and a sprue bush, and are characterized in that the movable die core and the fixed die core are respectively provided with three heating rods, aluminum liquid slowly enters a cavity from a material handle of the sprue bush through a flow channel, when mold filling is finished, the speed is switched to pressure, and a punch continuously pressurizes until a product is solidified.

Wherein the porosity of the silicon carbide prefabricated body is 10%, and the allowance of 1mm is reserved around the silicon carbide prefabricated body.

Wherein the working temperature of the die is 420-430 ℃; the silicon carbide prefabricated body needs to be put into an oven to be baked to 900 ℃, and can be used after more than 1 hour; the working temperature of the aluminum liquid is 730 plus 740 ℃.

After the aluminum-based silicon carbide is cast, the aluminum-based silicon carbide is taken out of the die, and is placed into a holding furnace within 10-15 seconds, the temperature of the holding furnace is reduced by 100 ℃ per hour at 500 ℃, and the aluminum-based silicon carbide is placed at 100 ℃ and cooled at room temperature.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts of the present invention are equivalent to or changed within the technical scope of the present invention.

Claims

1. The extrusion casting aluminum alloy infiltration mold for the silicon carbide composite material and the method thereof comprise a movable mold core, a fixed mold core and a sprue bush, and are characterized in that the movable mold core and the fixed mold core are respectively provided with three heating rods, aluminum liquid slowly enters a cavity from a material handle of the sprue bush through a flow channel, the speed is switched to pressure when mold filling is finished, and a punch continuously pressurizes until a product is solidified.

2. The die and method for infiltration of squeeze cast aluminum alloy of silicon carbide composite according to claim 1, wherein the porosity of the silicon carbide preform is 10% and the balance of 1mm is left around the silicon carbide preform.

3. The silicon carbide composite material infiltration mold and method for extrusion casting aluminum alloy as claimed in claim 1, wherein the mold working temperature is 420-430 ℃; the silicon carbide prefabricated body needs to be put into an oven to be baked to 900 ℃, and can be used after more than 1 hour; the working temperature of the aluminum liquid is 730 plus 740 ℃.

4. The die and the method for impregnating the silicon carbide composite material with the extrusion casting aluminum alloy according to claim 1, wherein the aluminum-based silicon carbide is taken out of the die after the casting is completed, and the die is placed into a holding furnace within 10 to 15 seconds, the holding furnace is set at 500 ℃, the temperature is reduced by 100 ℃ per hour until the die is placed at 100 ℃ and cooled at room temperature.