CN108796318B - High-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy and preparation method thereof - Google Patents

Abstract

The invention provides a high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy and a preparation method thereof, wherein the near-eutectic aluminum-silicon-copper-magnesium alloy comprises the following elements in percentage by mass: 9-11% of Si, Cu: 2.7-3.2%, Mg: 0.25 to 0.35%, Zr: 0.2-0.25%, Sr: 0.03 to 0.04%, Mn: 0.12-0.15%, Fe:0 < w (Fe) less than or equal to 0.2%, Zn: w (Zn) is more than 0 and less than or equal to 0.2 percent, and the balance is Al; the alloy is obtained through the preparation processes of raw material drying in the step (1), melting in the step (2), smelting in the step (3), detection in the step (4), refining in the step (5) and casting in the step (6). The mechanical property test result of the near-eutectic aluminum-silicon-copper-magnesium alloy provided by the invention is that, in an as-cast state: the room temperature tensile strength is 215-245MPa, the fracture elongation is 2-3.5%, and the Brinell hardness is 88-90; in the heat-treated state (T6): the tensile strength at room temperature is 410-440MPa, the elongation at break is 3.5-4.5, and the Brinell hardness is 125-130. The alloy of the invention can be used for preparing thin-wall and complex castings; the alloy is used for bearing heavy loads and large and medium-sized castings with complex shapes, and can meet the service requirements of important parts of aviation and automobiles.

Description

A kind of near-eutectic aluminum-silicon-copper-magnesium alloy with high strength and toughness and preparation method thereof

technical field

The invention belongs to the technical field of preparation of non-ferrous metal materials, in particular to a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy material and a preparation method thereof.

Background technique

In the fields of aviation and automobiles, many important parts (parts) are subjected to various mechanical loads and thermal loads, and are in high temperature, high pressure, and high-speed working conditions for a long time. Therefore, parts are required to have high room temperature and high temperature mechanical properties, dimensional stability and resistance to harsh working conditions and environments.

The lightweight of aviation and automotive materials is the future development direction. Excellent structural materials should have high specific strength to meet the strength requirements with a smaller cross-section and greatly reduce the weight of the zero (part) itself; good forming High strength and toughness are the basis for the production of complex shapes and thin-walled zero (parts) parts. At present, the high-strength and toughness alloys used for high-performance casting in the prior art are near-eutectic aluminum-silicon alloys, which require rare earth elements, which are distributed and dispersed in the earth's crust and are difficult to extract and separate; the preparation process is complex and the price is relatively high. high. The specific strength of the near-eutectic Al-Si alloys in the prior art is not high enough, and the formability and toughness cannot meet the requirements for preparing parts with complex structures, thin walls and high toughness. Therefore, there is an urgent need to develop a near-eutectic Al-Si-Cu-Mg alloy material with high strength and toughness, simple preparation process and low price.

Invention content:

The purpose of the present invention is to solve the technical problems existing in the prior art, and to provide a high-strength and toughness near-eutectic Al-Si-Cu-Mg alloy material and a preparation method thereof, which are especially suitable for castings with complex shape and structure, thin walls and high strength and toughness. (part.

To achieve the above purpose, the present invention adopts the following technical solutions:

A high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy, the near-eutectic aluminum-silicon-copper-magnesium alloy is an alloy obtained by preparing the elements in the following mass percentage ratios according to the following process, specifically including the following mass percentage elements:

Si: 9-11%, Cu: 2.7-3.2%, Mg: 0.25-0.35%, Zr: 0.2-0.25%, Sr: 0.03-0.04%, Mn: 0.12-0.15%, Fe: 0<w(Fe) ≤0.2%, Zn: 0<w(Zn)≤0.2%, and the balance is Al and trace unavoidable impurities.

The specific preparation process is:

Step (1) drying of raw materials: Weigh industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloy respectively; 0.3% non-toxic refining agent by weighing; industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloy, refining agent and aluminum ingot to be weighed Put it in a constant temperature preheating drying oven at 200℃ for 1.5-2h;

Step (2) melting: place the dried industrial silicon and aluminum ingots in step (1) in an industrial electric furnace, and set the furnace temperature to 850-950 ° C; electrify for 3-4 hours, and wait for the aluminum ingots for remelting in the furnace , All the industrial silicon is melted, the molten aluminum melt in the furnace is stirred for 10-15min, then the non-toxic refining agent preheated and dried in step (1) is added, and after stirring, it is allowed to stand for 5-10min, and the slag is skimming;

Step (3) Smelting: add the Al-50%Cu, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys dried in step (1) into the industrial electric furnace, and set the furnace The melt temperature is 800°C for 20-30min; after all the materials in the furnace are completely melted, adjust the temperature to 750-770°C, keep the temperature for 15-20min, add the remaining non-toxic refining agent in step (2), stir and let stand 5-10min, slag skimming; add the magnesium ingot after drying and preheating in step (1), and use a bell jar to press the magnesium ingot into the aluminum alloy melt until the magnesium ingot is completely melted, and gently stir for 5min;

Step (4) detection: fast sampling in front of the furnace, and measurement of characteristic parameters of the solidification process, to determine that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

Step (5) refining: introducing nitrogen into the aluminum alloy melt, further refining, the time of introduction is controlled at 5-10min, and the slag is skimming after standing for 5-10min;

Step (6) Casting: the whole aluminum alloy melt temperature is cast at 710±10° C., which is a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

Preferably, the industrial silicon weighed in step (1) is a block with a particle size of 1-3 cm ³ ; the non-toxic refining agent added in step (2) is 50% of the total amount of refining agent weighed in step (1).

Preferably, when the high-strength and toughness near-eutectic Al-Si-Cu-Mg alloy material is as-cast, the room temperature tensile strength is 215-245 MPa, the fracture elongation is 2-3.5%, and the Brinell hardness is 88-90.

Preferably, when using the obtained high-strength-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material to prepare a casting, the heat treatment process is carried out according to the following steps:

Solution treatment: place the castings in an industrial aluminum alloy heat treatment furnace, and implement a two-step solution treatment. The specific process is: 500 °C for 4 hours, then heated to 515 °C for 8 hours, and quickly quenched into 40-60 °C water;

Cooling after heat preservation: place the casting in an aluminum alloy aging furnace, keep it at 175°C for 8-12 hours, and air-cool it out of the furnace.

Preferably, the aging time for placing the casting in the alloy aging furnace can be adjusted according to the alloy performance requirements.

Preferably, in the heat-treated state of the alloy, the tensile strength at room temperature is 410-440 MPa, the elongation at break is 3.5-4.5, and the Brinell hardness is 125-130.

Preferably, it specifically includes the following steps:

Step (1) drying of raw materials: Weigh industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloy respectively; 0.3% non-toxic refining agent by weighing; industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloy, refining agent and aluminum ingot to be weighed Put it in a constant temperature preheating drying oven at 200℃ for 1.5-2h;

Step (2) melting: place the dried industrial silicon and aluminum ingots in step (1) in an industrial electric furnace, and set the furnace temperature to 850-950 ° C; electrify for 3-4 hours, and wait for the aluminum ingots for remelting in the furnace , All the industrial silicon is melted, the molten aluminum melt in the furnace is stirred for 10-15min, then some non-toxic refining agents preheated and dried in step (1) are added, and after stirring, let stand for 5-10min, and the slag is skimming;

Step (3) Smelting: add the Al-50%Cu, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys dried in step (1) into the industrial electric furnace, and set the furnace The melt temperature is 800°C for 20-30min; after all the materials in the furnace are completely melted, adjust the temperature to 750-775°C, keep the temperature for 15-25min, add the remaining non-toxic refining agent in step (2), stir and let stand 5-10min, skim the slag; add the dried and preheated magnesium ingot in step (1), and use a bell jar to press the magnesium ingot into the aluminum alloy melt until the magnesium ingot is completely melted, and gently stir for 5min;

Step (4) detection: fast sampling in front of the furnace, and measurement of characteristic parameters of the solidification process, to determine that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

Step (5) refining: nitrogen is introduced into the aluminum alloy melt, and further refining is carried out, the time of introduction is controlled at 5-10min, and the slag is skimming for 5-10min;

Step (6) Casting: the whole aluminum alloy melt temperature is cast at 710±10° C., which is a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

Preferably, the industrial silicon weighed in step (1) is a block with a particle size of 1-3 cm ³ ; the non-toxic refining agent added in step (2) is 50% of the total amount of refining agent weighed in step (1).

The invention designs the alloy composition by calculating the phase diagram, adjusts the alloying elements and the heat treatment process, and prepares a near-eutectic aluminum-silicon alloy material with good formability and high strength and toughness, which can meet the requirements of important parts (parts) in the fields of aviation and automobiles. material requirements.

The advantages and positive effects of the present invention are:

1. The present invention is based on the Al-Si alloy, based on the calculated phase diagram, the composition design is carried out, and the elements for strengthening, modification and refinement of alloy elements are added, and the prepared near-eutectic alloy material has the characteristics of high strength and toughness.

2. The alloy material has good casting properties, mechanical properties at room temperature and high temperature, and can form complex cylinder parts; and the material has low price and simple production process, and is suitable for industrial mass production.

3. Mn in the present invention can be used as a microalloying element to reduce the harm of Fe element, improve the morphology characteristics of the Fe-rich phase in the alloy, and improve the mechanical properties of the alloy;

As the main alloying elements, Cu and Mg can form complex strengthening phases with other elements and improve the mechanical properties of the alloy at room temperature and high temperature;

Sr transforms the coarse flaky eutectic Si into fine fibers, improves the flow properties of the alloy, and improves the mechanical properties of the alloy, especially the elongation at fracture;

Zr not only refines the Al phase, but also improves the strengthening effect of alloying elements and greatly improves the mechanical properties of the alloy. At the same time, Zr can combine with H in the melt to form ZrH, which can better reduce the number of pinholes in the casting.

4. In the heat treatment process, through the two-step solid solution treatment, the speed of the solid solution of the strengthening elements to the matrix is accelerated, and the alloy will not be overheated or overburned; at the same time, it saves energy, shortens the production cycle, and improves productivity.

5. The alloy of the present invention can obtain different strength and fracture elongation by adjusting the heat treatment process; that is, according to the service requirements of the material, both strength and plasticity can meet the requirements; at the same time, complex thin-walled structural castings can be formed;

6. The prepared new near-eutectic aluminum-silicon alloy material has good mechanical properties. In the as-cast state, the tensile strength at room temperature is 215-245MPa, the fracture elongation is 2-3.5%, and the Brinell hardness is 88-90; the heat treatment state ( T6): the tensile strength at room temperature is 410-440MPa, the elongation at break is 3.5-4.5, and the Brinell hardness is 125-130.

Description of drawings

Fig. 1 is the microstructure (SEM scanning electron microscope photo) of unmodified alloy in Example 1 of the present invention;

Fig. 2 is the microstructure (SEM scanning electron microscope photo) of Sr modified alloy in Example 1 of the present invention;

Fig. 3 is the microstructure (SEM scanning electron microscope photo) of the heat-treated alloy in Example 1 of the present invention;

Fig. 4 is heat-treated state aging precipitation strengthening phase (TEM electron microscope photo) in the embodiment of the present invention 1;

Fig. 5 is the fracture morphology (SEM scanning electron microscope photo) of the unmodified alloy in the as-cast state of the alloy in Example 2 of the present invention;

Fig. 6 is the fracture morphology of the Sr modified alloy in the as-cast state of the alloy in Example 2 of the present invention (SEM photo);

7 is the fracture morphology of the alloy after heat treatment in Example 2 of the present invention (T6, SEM scanning electron microscope photos).

Detailed ways

Selected embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that the descriptions of the embodiments of the present invention are merely exemplary and are not intended to limit the solutions of the present invention.

Example 1

(1) According to the mass percentage of alloying elements in the Al-Si alloy Si: 10.36%, Cu: 3.05%, Mg: 0.30%, Zr: 0.24%, Sr: 0.04%, Mn: 0.12%, Zn: 0.015% , Fe: 0.018%, the balance is Al and trace unavoidable impurities, respectively weigh industrial Si, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr Master alloy; of which industrial Si is a block with a particle size ^of 1-3cm;

(2) take by weighing 0.3% of the total feed weight of step (1) non-toxic refining agent (TR-L);

(3) The industrial Si, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloy, aluminum ingot and The sodium-free refining agent is placed in a constant temperature preheating drying oven with a temperature of 200 ° C for drying for 2 hours;

(4) put industrial silicon and aluminum ingot after drying in step (3) into the industrial electric furnace, and set the industrial electric furnace temperature to be 900 ℃;

(5) electrify for 4h, until all the aluminum ingots and industrial silicon for remelting in the furnace are melted, stir the molten aluminum melt in the furnace for 10min, and then add half of the total amount of the nontoxic refining agent weighed in step (1), Stir and let stand for 8 minutes, skimming.

(6) Add the Al-50% copper, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy dried in step (3) into the industrial electric furnace, and set the melt temperature in the furnace to be 800℃ for 30min;

(7) After all the materials in the furnace are completely melted, adjust the temperature to 775 ° C, keep the temperature for 25 minutes, add the remaining non-toxic refining agent, stir and let stand for 10 minutes, and skim the slag.

(8) use the bell jar to press the magnesium ingot into the aluminum alloy melt for 5min until the magnesium ingot is completely melted, and stir rapidly for 5min;

(9) Through the rapid sampling in front of the furnace and the measurement of the characteristic parameters of the solidification process, it is determined that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

(10) nitrogen is introduced into the aluminum alloy melt, further refining is carried out, the time of introduction is controlled at 8min, and the slag is skimming after standing for 5min;

(11) Adjust the temperature of the aluminum alloy melt, and pour it out of the furnace at 715 °C, which is a near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

The non-toxic refining agent used in the present embodiment 1 is the sodium-free high-efficiency degassing and slag-removing refining agent produced by Xuzhou Huazhong Aluminum Company.

When using the high-strength-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in Example 1 to prepare a casting, the heat treatment process is carried out according to the following steps:

(1) The casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solution treatment is performed. The specific process is: 500 °C for 4 hours, then heated to 515 °C for 8 hours, and quickly quenched into 40 °C water;

(2) Put the castings in an aluminum alloy aging furnace, keep the temperature at 175 °C for 9 hours, and release them for air cooling;

Through sampling inspection, the aluminum alloy mechanical property test result prepared in the present embodiment 1 is:

As-cast: strength at room temperature is 230MPa, Brinell hardness (HBS) is 90, elongation at break is 2.6%;

Heat treatment state (T6): the tensile strength at room temperature is 411MPa, the Brinell hardness (HBS) is 127, and the elongation at break is 4.2%;

Example 2

(1) According to the mass percentage of alloying elements in the Al-Si alloy, Si: 9.6%, Cu: 3.20%, Mg: 0.35%, Zr: 0.23%, Sr: 0.035%, Mn: 0.13%, Zn: 0.011% , Fe: 0.016%, the balance is Al and a trace amount of inevitable impurities, respectively weigh industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr Master alloy; of which industrial Si is a block with a particle size ^of 1-3cm;

(2) take by weighing 0.3% of the total feed weight of step (1) non-toxic refining agent (TR-L);

(3) The industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy, aluminum ingot and The sodium-free refining agent is placed in a constant temperature preheating drying oven with a temperature of 200 ° C for drying for 2 hours;

(4) put industrial silicon and aluminum ingot after drying in step (3) into the industrial electric furnace, and set the industrial electric furnace temperature to be 900 ℃;

(5) energize for 4h, until all the aluminum ingots and industrial silicon for remelting in the furnace are melted, stir the molten aluminum melt in the furnace for 10min, then add half of the non-toxic refining agent weighed in step (1), stir and Let stand for 10min and skim.

(6) Add the Al-50% copper, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy dried in step (3) into the industrial electric furnace, and set the melt temperature in the furnace to be 800℃ for 30min;

(7) After all the materials in the furnace are completely melted, adjust the temperature to 770 ° C, keep the temperature for 20 minutes, add the remaining non-toxic refining agent, stir and let stand for 10 minutes, and skim the slag.

(8) press the magnesium ingot into the aluminum alloy melt with a bell until the magnesium ingot is completely melted, and stir rapidly for 5min;

(9) Through the rapid sampling in front of the furnace and the measurement of the characteristic parameters of the solidification process, it is determined that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

(10) nitrogen is introduced into the aluminum alloy melt, further refining is carried out, the time of introduction is controlled at 10min, and the slag is skimming after standing for 8min;

(11) Adjust the temperature of the aluminum alloy melt, and pour it out of the furnace at 720 ° C, which is a near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

The non-toxic refining agent used in the present embodiment 2 is the sodium-free high-efficiency degassing and slag-removing refining agent produced by Xuzhou Huazhong Aluminum Company.

When using the high-strength-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the present embodiment 2 to prepare the casting, the heat treatment process is carried out according to the following steps:

(1) The casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solution treatment is performed. The specific process is: 500 °C for 4 hours, then heated to 515 °C for 8 hours, and quickly quenched into 50 °C water;

(2) Put the castings in an aluminum alloy aging furnace, keep the temperature at 175 °C for 12 hours, and release them for air cooling;

Through sampling inspection, the aluminum alloy mechanical property test result prepared in the present embodiment 2 is:

As-cast: strength at room temperature is 243MPa, Brinell hardness (HBS) is 88, elongation at break is 3.2%;

Heat treatment state (T6): the tensile strength at room temperature is 431MPa, the Brinell hardness (HBS) is 129, and the elongation at break is 3.6%;

Example 3

(1) According to the mass percentage of alloying elements in the Al-Si alloy, Si: 9%, Cu: 2.7%, Mg: 0.25%, Zr: 0.2%, Sr: 0.03%, Mn: 0.15%, Zn: 0.02% , Fe: 0.02%, the balance is Al and a trace amount of unavoidable impurities, respectively weigh industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr Master alloy; of which the industrial Si is in the form of a block with a particle size of 1-3cm3;

(2) take by weighing 0.3% of the total feed weight of step (1) non-toxic refining agent (TR-L);

(3) The industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy, aluminum ingot and The sodium-free refining agent is placed in a constant temperature preheating drying oven with a temperature of 200 °C to dry for 1.5 hours;

(4) put industrial silicon and aluminum ingot after drying in step (3) into the industrial electric furnace, and set the industrial electric furnace temperature to be 850 ℃;

(5) energize for 3h, until all the aluminum ingots and industrial silicon for remelting in the furnace are melted, stir the molten aluminum melt in the furnace for 15min, then add half of the nontoxic refining agent weighed in step (1), stir and Let stand for 5 minutes and skim.

(6) Add the Al-50% copper, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy dried in step (3) into the industrial electric furnace, and set the melt temperature in the furnace to be 800℃ for 20min;

(7) After all the materials in the furnace are completely melted, adjust the temperature to 750 ° C, keep the temperature for 15 minutes, add the remaining non-toxic refining agent, stir and let stand for 5 minutes, and skim the slag.

(8) press the magnesium ingot into the aluminum alloy melt with a bell until the magnesium ingot is completely melted, and stir rapidly for 5min;

(9) Through the rapid sampling in front of the furnace and the measurement of the characteristic parameters of the solidification process, it is determined that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, the time of introduction is controlled at 5min, and the slag is skimming after standing for 10min;

(11) Adjust the temperature of the aluminum alloy melt and cast it at 700°C, which is a near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

The non-toxic refining agent used in the present embodiment 2 is the sodium-free high-efficiency degassing and slag-removing refining agent produced by Xuzhou Huazhong Aluminum Company.

When using the high-strength-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the present embodiment 2 to prepare the casting, the heat treatment process is carried out according to the following steps:

(1) Place the casting in an industrial aluminum alloy heat treatment furnace, and implement a two-step solution treatment. The specific process is: 500 °C for 4 hours, then heated to 515 °C for 8 hours, and quickly quenched into 60 °C water;

(2) Put the castings in an aluminum alloy aging furnace, keep the temperature at 175 °C for 8 hours, and release them for air cooling;

Through sampling inspection, the test results of the mechanical properties of the aluminum alloy prepared by this experimental method are as follows:

As-cast: strength at room temperature is 235MPa, elongation at break is 2.8%, Brinell hardness (HBS) is 90;

Heat treatment state (T6): the strength reaches 430MPa, the elongation at break reaches 4%, and the Brinell hardness (HBS) is 130.

Example 4

(1) According to the mass percentage of alloying elements in the Al-Si alloy Si: 11%, Cu: 3.20%, Mg: 0.35%, Zr: 0.25%, Sr: 0.04%, Mn: 0.14%, Zn: 0.2% , Fe: 0.2%, the balance is Al and a trace amount of inevitable impurities, respectively weigh industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr Master alloy; of which industrial Si is a block with a particle size ^of 1-3cm;

(2) take by weighing 0.3% of the total feed weight of step (1) non-toxic refining agent (TR-L);

(3) The industrial Si, Al-50% copper, magnesium ingot, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy, aluminum ingot and The sodium-free refining agent is placed in a constant temperature preheating drying oven with a temperature of 200 ° C for drying for 2 hours;

(4) put industrial silicon and aluminum ingot after drying in step (3) into the industrial electric furnace, and set the industrial electric furnace temperature to be 950 ℃;

(5) Power on for 3.5 hours, until all the aluminum ingots and industrial silicon for remelting in the furnace are melted, stir the molten aluminum melt in the furnace for 15 minutes, then add half of the non-toxic refining agent weighed in step (1), stir And let stand for 10min, skimming.

(6) Add the Al-50% copper, Al-5% Zr, Al-10% Mn, Al-10% Sr master alloy dried in step (3) into the industrial electric furnace, and set the melt temperature in the furnace to be 800℃ for 25min;

(7) After all the materials in the furnace are completely melted, adjust the temperature to 760 ° C, keep the temperature for 20 minutes, add the remaining non-toxic refining agent, stir and let stand for 10 minutes, and skim the slag.

(8) press the magnesium ingot into the aluminum alloy melt with a bell until the magnesium ingot is completely melted, and stir rapidly for 5min;

(9) Through the rapid sampling in front of the furnace and the measurement of the characteristic parameters of the solidification process, it is determined that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, the time of introduction is controlled at 10min, and the slag is skimming after standing for 10min;

(11) Adjust the temperature of the aluminum alloy melt, and pour it out of the furnace at 715 °C, which is a near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

The non-toxic refining agent used in the present embodiment 2 is the sodium-free high-efficiency degassing and slag-removing refining agent produced by Xuzhou Huazhong Aluminum Company.

When using the high-strength-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the present embodiment 2 to prepare the casting, the heat treatment process is carried out according to the following steps:

(1) The casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solution treatment is carried out. The specific process is: 500 °C for 4 hours, then heated to 515 °C for 8 hours, and quickly quenched into 45 °C water;

(2) Put the casting in an aluminum alloy aging furnace, keep it at 175°C for 10h, and release it for air cooling;

Through sampling inspection, the test results of the mechanical properties of the aluminum alloy prepared by this experimental method are as follows:

As-cast: strength at room temperature is 245MPa, Brinell hardness (HBS) is 89, elongation at break is 3.4%;

Heat treatment state (T6): the tensile strength at room temperature is 435MPa, the Brinell hardness (HBS) is 128, and the elongation at break is 3.8%;

Comparative ratio

The mechanical properties of the ZL111 aluminum alloy in the prior art and the alloy material of the present invention were respectively tested, and the results are shown in Table 1.

It can be seen that the as-cast and heat-treated mechanical properties of the alloy of the present invention are significantly better than those of the ZL111 aluminum alloy, indicating that the alloy material of the present invention has better tensile strength and toughness.

Table 1 Comparison table of performance test of alloy material of the present invention and ZL111 aluminum alloy

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application rather than to limit its protection scope. Although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand: Those skilled in the art can still make various changes, modifications or equivalent replacements to the specific embodiments of the application after reading this application, but the above changes, modifications or equivalent replacements are all within the scope of protection of the pending or pending claims of this application. Inside.

Claims (4)

1. a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy, is characterized in that, described near-eutectic aluminum-silicon-copper-magnesium alloy is the alloy obtained after preparing by following technology to the element of following mass percentage ratio, The elements in the following mass percentage ratios are: Si: 9-11%, Cu: 2.7-3.2%, Mg: 0.25-0.35%, Zr: 0.2-0.25%, Sr: 0.03-0.04%, Mn: 0.12-0.15%, Fe: 0<w(Fe) ≤0.2%, Zn: 0<w(Zn)≤0.2%, the balance is Al; the room temperature tensile strength of the alloy in as-cast state is 215-245MPa, and the fracture elongation rate is 2-3.5%; Described following preparation technology is: Step (1) drying of raw materials: Weigh out the industrial silicon, Al-50%Cu, magnesium ingots, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys with a particle size of ^1-3cm3 respectively; Then weigh the non-toxic refining agent according to 0.3% of the total input weight of the aforementioned raw materials; the weighed industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr The master alloy, refining agent and aluminum ingot are placed in a constant temperature preheating drying furnace at 200°C to dry for 1.5-2h; Step (2) melting: the dried industrial silicon and aluminum ingots in step (1) are placed in an industrial electric furnace, and the furnace temperature is set to 850-950 ° C; the aluminum ingots and industrial silicon for remelting in the furnace are all melted , stir the molten aluminum melt in the furnace for 10-15min, then add 50% of the total amount of the non-toxic refining agent preheated and dried in the step (1), and let stand for 5-10min after stirring to skim the slag; Step (3) Smelting: add the Al-50%Cu, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys dried in step (1) into the industrial electric furnace, and set the furnace The melt temperature is 800°C; after all the materials in the furnace are completely melted, adjust the temperature to 750-775°C, keep the temperature for 15-25min, add the remaining non-toxic refining agent in the step (2), stir and let stand for 5- 10min, slag skimming; add the magnesium ingot after drying and preheating in step (1), press the magnesium ingot into the aluminum alloy melt until the magnesium ingot is completely melted, and gently stir for 5min; Step (4) detection: fast sampling in front of the furnace, and measurement of characteristic parameters of the solidification process, to determine that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements; Step (5) refining: nitrogen is introduced into the aluminum alloy melt, and further refining is performed, the introduction time is controlled at 5-10min, and the slag is left for 5-10min for skimming; Step (6) Casting: adjusting the temperature of the aluminum alloy melt, and casting at 710±10° C., which is a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material. 2. a kind of high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy according to claim 1, is characterized in that, when adopting the high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in claim 1 to prepare casting, according to The following steps carry out the heat treatment process: Solution treatment: The casting is placed in an industrial aluminum alloy heat treatment furnace, and a two-step solution treatment is performed. The specific process is: 500 ° C for 4 hours, then heated to 515 ° C for 8 hours, and quickly quenched into 40-60 ° C water ; Cooling after heat preservation: place the casting in an aluminum alloy aging furnace, keep it at 175°C for 8-12 hours, and air-cool it out of the furnace. 3. The high-strength and toughness near-eutectic Al-Si-Cu-Mg alloy according to claim 2, wherein the alloy has a tensile strength at room temperature of 410-440 MPa and an elongation at break of 3.5-3. 4.5%. 4. a preparation method for preparing the near-eutectic Al-Si-Cu-Mg alloy with high strength and toughness as claimed in claim 1, is characterized in that, specifically comprises the steps: Step (1) drying of raw materials: Weigh out the industrial silicon, Al-50%Cu, magnesium ingots, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys with a particle size of ^1-3cm3 respectively; Then weigh the non-toxic refining agent according to 0.3% of the total input weight of the aforementioned raw materials; the weighed industrial silicon, Al-50%Cu, magnesium ingot, Al-5%Zr, Al-10%Mn, Al-10%Sr The master alloy, refining agent and aluminum ingot are placed in a constant temperature preheating drying furnace at 200°C to dry for 1.5-2h; Step (2) melting: place the dried industrial silicon and aluminum ingots in step (1) in an industrial electric furnace, and set the furnace temperature to 850-950 ° C; electrify for 3-4 hours, and wait for the aluminum ingots for remelting in the furnace , all the industrial silicon is melted, the molten aluminum melt in the furnace is stirred for 10-15min, then 50% of the total amount of the non-toxic refining agent preheated and dried in the step (1) is added, and after stirring, let stand for 5-10min, skim slag; Step (3) Smelting: add the Al-50%Cu, Al-5%Zr, Al-10%Mn, Al-10%Sr master alloys dried in step (1) into the industrial electric furnace, and set the furnace The melt temperature is 800°C for 20-30min; after all the materials in the furnace are completely melted, adjust the temperature to 750-770°C, keep the temperature for 15-20min, add the remaining nontoxic refining agent in the step (2), stir and mix. Let stand for 5-10min, and skim the slag; add the dried and preheated magnesium ingot in step (1), and use a bell jar to press the magnesium ingot into the aluminum alloy melt until the magnesium ingot is completely melted, and gently stir for 5min; Step (4) detection: fast sampling in front of the furnace, and measurement of characteristic parameters of the solidification process, to determine that the composition is qualified, the eutectic Si modification, and the aluminum phase refinement meet the requirements; Step (5) refining: introducing nitrogen into the aluminum alloy melt, further refining, the time of introduction is controlled at 5-10min, and the slag is skimming after standing for 5-10min; Step (6) Casting: adjusting the temperature of the aluminum alloy melt, and casting at 710±10° C., which is a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

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