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

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

Technical Field

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

Background

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

The light weight of aviation and automobile materials is the future development direction, and excellent structural materials have higher specific strength, so that the strength requirement can be met by a smaller section, and the self weight of parts is greatly reduced; good formability and high toughness, and is the basis for producing thin-wall parts with complex shapes. At present, in the prior art, the high-strength and high-toughness alloy for high-performance casting is a near-eutectic aluminum-silicon alloy, and rare earth elements are needed to be adopted during preparation, are distributed and dispersed in the earth crust and are difficult to extract and separate; the preparation process is complex and the price is high. The near eutectic aluminum-silicon alloy in the prior art has low specific strength, and the formability and the obdurability can not meet the requirements of preparing parts with complex structures, thin walls and high toughness. Therefore, the development of a near-eutectic aluminum-silicon-copper-magnesium alloy material with high strength and toughness, simple preparation process and lower price is urgently needed.

The invention content is as follows:

the invention aims to solve the technical problems in the prior art, provides a high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material and a preparation method thereof, and is particularly suitable for casting parts with complicated shapes and structures, thin walls and high toughness.

In order to achieve the purpose, the invention adopts the following technical scheme:

the near-eutectic aluminum-silicon-copper-magnesium alloy with high strength and toughness is prepared by the following steps of:

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: 0 < w (Zn) is less than or equal to 0.2 percent, and the balance is Al and trace inevitable impurities.

The specific preparation process comprises the following steps:

drying raw materials in the step (1): respectively weighing industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr intermediate alloy; then weighing a non-toxic refining agent according to 0.3 percent of the total feeding weight of the raw materials; putting the weighed industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, refining agent and aluminum ingot into a constant-temperature preheating drying furnace at 200 ℃ for drying for 1.5-2 h;

melting in step (2): placing the industrial silicon and aluminum ingots dried in the step (1) in an industrial electric furnace, and setting the furnace temperature to 850-; electrifying for 3-4h, stirring the molten aluminum in the furnace for 10-15min after remelting in the furnace uses aluminum ingots and industrial silicon to be completely melted, then adding the non-toxic refining agent preheated and dried in the step (1), stirring, standing for 5-10min, and skimming;

smelting in step (3): adding intermediate alloys of Al-50% Cu, Al-5% Zr, Al-10% Mn and Al-10% Sr dried in the step (1) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 20-30 min; when all materials in the furnace are completely melted down, adjusting the temperature to 750-770 ℃, preserving the heat for 15-20min, adding the residual non-toxic refining agent in the step (2), stirring and standing for 5-10min, and skimming; adding the dried and preheated magnesium ingot in the step (1), pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely molten, and slightly stirring for 5 min;

and (4) detecting: through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

refining in step (5): introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 5-10min, standing for 5-10min, and skimming;

step (6) casting: and the temperature of the whole aluminum alloy melt is taken out of the furnace and poured at 710 +/-10 ℃, thus obtaining the high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

Preferably, the industrial silicon weighed in the step (1) has the granularity of 1-3cm³Block-shaped; the non-toxic refining agent added in the step (2) accounts for 50% of the total amount of the refining agent weighed in the step (1).

Preferably, when the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material is in an 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.

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

solution treatment: the casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solid solution treatment is implemented, and the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 40-60 ℃;

and (3) cooling after heat preservation: and (3) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 8-12h, discharging and air cooling.

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

Preferably, the alloy has a room temperature tensile strength of 410-440MPa, a fracture elongation of 3.5-4.5 and a Brinell hardness of 125-130 in a heat treatment state.

Preferably, the method specifically comprises the following steps:

drying raw materials in the step (1): respectively weighing industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr intermediate alloy; then weighing a non-toxic refining agent according to 0.3 percent of the total feeding weight of the raw materials; putting the weighed industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, refining agent and aluminum ingot into a constant-temperature preheating drying furnace at 200 ℃ for drying for 1.5-2 h;

melting in step (2): placing the industrial silicon and aluminum ingots dried in the step (1) in an industrial electric furnace, and setting the furnace temperature to 850-; electrifying for 3-4h, stirring the molten aluminum in the furnace for 10-15min after remelting in the furnace uses aluminum ingots and industrial silicon to be completely melted, then adding part of the non-toxic refining agent preheated and dried in the step (1), stirring, standing for 5-10min, and skimming;

smelting in step (3): adding intermediate alloys of Al-50% Cu, Al-5% Zr, Al-10% Mn and Al-10% Sr dried in the step (1) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 20-30 min; after all the materials in the furnace are completely melted down, adjusting the temperature to 750-775 ℃, preserving the heat for 15-25min, adding the residual non-toxic refining agent in the step (2), stirring and standing for 5-10min, and skimming; adding the dried and preheated magnesium ingot in the step (1), pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely molten, and slightly stirring for 5 min;

and (4) detecting: through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

refining in step (5): introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 5-10min, standing for 5-10min, and skimming;

step (6) casting: and the temperature of the whole aluminum alloy melt is taken out of the furnace and poured at 710 +/-10 ℃, thus obtaining the high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

Preferably, the industrial silicon weighed in the step (1) has the granularity of 1-3cm³Block-shaped; the non-toxic refining agent added in the step (2) accounts for 50% of the total amount of the refining agent weighed in the step (1).

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

The invention has the advantages and positive effects that:

1. the invention is based on Al-Si alloy, based on the calculation phase diagram, carries out component design, adds elements for strengthening, modifying and refining alloy elements, and prepares the near-eutectic alloy material with the characteristics of high obdurability.

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

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

cu and Mg as main alloying elements can form a complex strengthening phase with other elements, so that the mechanical properties of the alloy at room temperature and high temperature are improved;

sr converts coarse flaky eutectic Si into fine fibers, improves the fluidity of the alloy, and improves the mechanical properties of the alloy, especially the fracture elongation;

zr not only refines Al phase, but also improves the strengthening effect of alloy elements and greatly improves the mechanical property of the alloy. Meanwhile, Zr can be combined with H in the melt to form ZrH, so that the number of casting pinholes is reduced well.

4. In the heat treatment process, the speed of the strengthening elements for dissolving into the matrix is accelerated through two-step solution treatment, and the phenomenon of overheating or overburning of the alloy is avoided; meanwhile, the energy is saved, the production period is shortened, and the production efficiency is improved.

5. The alloy of the invention can obtain different strengths and fracture elongation rates by adjusting the heat treatment process; namely, the strength and the plasticity can meet the requirements according to the service requirements of the material; meanwhile, a complex thin-wall structure casting can be formed;

6. the prepared novel near-eutectic aluminum-silicon alloy material has good mechanical property and is as-cast: 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.

Drawings

FIG. 1 is a microstructure (SEM) of an undenatured alloy in example 1 of the present invention;

FIG. 2 is a microstructure (SEM scanning electron micrograph) of a Sr modified alloy in example 1 of the present invention;

FIG. 3 is a microstructure (SEM) of the alloy in a heat-treated state in example 1 of the present invention;

FIG. 4 is a TEM image of a thermally treated aged precipitation-strengthened phase in example 1 of the present invention;

FIG. 5 shows the fracture morphology (SEM scanning electron micrograph) of the unmodified alloy in the as-cast state in the alloy of example 2 of the invention;

FIG. 6 shows the Sr modified alloy fracture morphology (SEM scanning electron micrograph) of the alloy in the as-cast state in example 2 of the present invention;

FIG. 7 shows the fracture morphology (T6, SEM) of the alloy after heat treatment in example 2 of the present invention.

Detailed Description

Reference will now be made to the drawings in the specification to illustrate selected embodiments of the present invention, it being understood by those skilled in the art that the illustrations of embodiments of the invention are exemplary only and are not intended to limit the scope of the invention.

Example 1

(1) According to the mass percentage of alloy elements in the aluminum-silicon alloy, Si: 10.36%, Cu: 3.05%, Mg: 0.30%, Zr: 0.24%, Sr: 0.04%, Mn: 0.12%, Zn: 0.015 percent of Fe, 0.018 percent of Al and trace inevitable impurities, and respectively weighing industrial Si, Al-50 percent of Cu, magnesium ingot, Al-5 percent of Zr, Al-10 percent of Mn and Al-10 percent of Sr intermediate alloy; wherein the industrial Si has a particle size of 1-3cm³Block-shaped;

(2) weighing a non-toxic refining agent (TR-L) according to 0.3 percent of the total feeding weight in the step (1);

(3) putting the industrial Si, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, aluminum ingot and sodium-free refining agent in the steps (1) and (2) into a constant-temperature preheating drying furnace at the temperature of 200 ℃ for drying for 2 hours;

(4) putting the industrial silicon and aluminum ingots dried in the step (3) into an industrial electric furnace, and setting the furnace temperature of the industrial electric furnace to 900 ℃;

(5) electrifying for 4h, stirring the molten aluminum in the furnace for 10min after the remelting aluminum ingot and the industrial silicon in the furnace are completely melted, then adding half of the total amount of the nontoxic refining agent weighed in the step (1), stirring and standing for 8min, and skimming.

(6) Adding the intermediate alloy of Al-50% of copper, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr dried in the step (3) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 30 min;

(7) and (3) when all materials in the furnace are completely melted down, adjusting the temperature to 775 ℃, preserving the heat for 25min, adding the rest non-toxic refining agent, stirring and standing for 10min, and skimming slag.

(8) Pressing the magnesium ingot into the aluminum alloy melt for 5min by using a bell jar until the magnesium ingot is completely melted, and rapidly stirring for 5 min;

(9) through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 8min, standing for 5min, and skimming;

(11) adjusting the temperature of the aluminum alloy melt, and tapping and casting at 715 ℃ to obtain the near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

In this example 1, the non-toxic refining agent is a sodium-free high-efficiency degassing and deslagging refining agent manufactured by Xuzhou Huazhong aluminum industry.

When the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the embodiment 1 is used for preparing a casting, a heat treatment process is performed according to the following steps:

(1) the casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solid solution treatment is implemented, and the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 40 ℃;

(2) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 9h, discharging and air cooling;

through sampling inspection, the mechanical property detection result of the aluminum alloy prepared in the embodiment 1 is as follows:

as-cast state: the room temperature strength reaches 230MPa, the Brinell Hardness (HBS) is 90, and the fracture elongation reaches 2.6%;

heat treated state (T6): the tensile strength at room temperature reaches 411MPa, the Brinell Hardness (HBS) is 127, and the fracture elongation reaches 4.2%;

example 2

(1) According to the mass percentage of alloy elements in the aluminum-silicon alloy, Si: 9.6%, Cu: 3.20%, Mg: 0.35%, Zr: 0.23%, Sr: 0.035%, Mn: 0.13%, Zn: 0.011 percent, 0.016 percent of Fe, the balance of Al and trace inevitable impurities, and respectively weighing intermediate alloys of industrial Si, Al-50 percent of copper, magnesium ingot, Al-5 percent of Zr, Al-10 percent of Mn and Al-10 percent of Sr; wherein the industrial Si has a particle size of 1-3cm³Block-shaped;

(2) weighing a non-toxic refining agent (TR-L) according to 0.3 percent of the total feeding weight in the step (1);

(3) putting the industrial Si, Al-50% of copper, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, aluminum ingot and sodium-free refining agent in the steps (1) and (2) into a constant-temperature preheating drying furnace at the temperature of 200 ℃ for drying for 2 hours;

(4) putting the industrial silicon and aluminum ingots dried in the step (3) into an industrial electric furnace, and setting the furnace temperature of the industrial electric furnace to 900 ℃;

(5) electrifying for 4h, stirring the molten aluminum in the furnace for 10min after remelting in the furnace uses aluminum ingots and industrial silicon to be completely melted, then adding half of the nontoxic refining agent weighed in the step (1), stirring and standing for 10min, and skimming.

(6) Adding the intermediate alloy of Al-50% of copper, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr dried in the step (3) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 30 min;

(7) and (3) when all materials in the furnace are completely melted down, adjusting the temperature to 770 ℃, preserving the heat for 20min, adding the rest non-toxic refining agent, stirring and standing for 10min, and skimming slag.

(8) Pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely melted, and rapidly stirring for 5 min;

(9) through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 10min, standing for 8min, and skimming;

(11) adjusting the temperature of the aluminum alloy melt, discharging and casting at 720 ℃, and obtaining the near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

In this example 2, the non-toxic refining agent is a sodium-free high-efficiency degassing and deslagging refining agent manufactured by Xuzhou Huazhong aluminum industry.

When the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the embodiment 2 is used for preparing a casting, a heat treatment process is performed according to the following steps:

(1) the casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solid solution treatment is implemented, and the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 50 ℃;

(2) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 12h, discharging and air cooling;

through sampling inspection, the mechanical property detection result of the aluminum alloy prepared in the embodiment 2 is as follows:

as-cast state: the room temperature strength reaches 243MPa, the Brinell Hardness (HBS) is 88, and the fracture elongation reaches 3.2%;

heat treated state (T6): tensile strength at room temperature reaches 431MPa, Brinell Hardness (HBS) is 129, and fracture elongation reaches 3.6%;

example 3

(1) According to the mass percentage of alloy elements in the aluminum-silicon alloy, Si: 9%, Cu: 2.7%, Mg: 0.25%, Zr: 0.2%, Sr: 0.03%, Mn: 0.15%, Zn: 0.02 percent of Fe, 0.02 percent of Al and trace inevitable impurities, and respectively weighing industrial Si, Al-50 percent of copper, magnesium ingot, Al-5 percent of Zr, Al-10 percent of Mn and Al-10 percent of Sr intermediate alloy; wherein the industrial Si is in the form of 3 blocks with the granularity of 1-3 cm;

(2) weighing a non-toxic refining agent (TR-L) according to 0.3 percent of the total feeding weight in the step (1);

(3) putting the industrial Si, Al-50% of copper, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, aluminum ingot and sodium-free refining agent in the steps (1) and (2) into a constant-temperature preheating drying furnace at the temperature of 200 ℃ for drying for 1.5 h;

(4) putting the industrial silicon and aluminum ingots dried in the step (3) into an industrial electric furnace, and setting the furnace temperature of the industrial electric furnace to 850 ℃;

(5) electrifying for 3h, stirring the molten aluminum in the furnace for 15min after the remelting aluminum ingot and the industrial silicon in the furnace are completely melted, then adding half of the non-toxic refining agent weighed in the step (1), stirring and standing for 5min, and skimming.

(6) Adding the intermediate alloy of Al-50% of copper, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr dried in the step (3) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 20 min;

(7) and (3) when all materials in the furnace are completely melted down, adjusting the temperature to 750 ℃, preserving the heat for 15min, adding the rest non-toxic refining agent, stirring and standing for 5min, and skimming slag.

(8) Pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely melted, and rapidly stirring for 5 min;

(9) through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 5min, standing for 10min, and skimming;

(11) adjusting the temperature of the aluminum alloy melt, tapping at 700 ℃ and casting to obtain the near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

In this example 2, the non-toxic refining agent is a sodium-free high-efficiency degassing and deslagging refining agent manufactured by Xuzhou Huazhong aluminum industry.

When the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the embodiment 2 is used for preparing a casting, a heat treatment process is performed according to the following steps:

(1) the casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solid solution treatment is implemented, and the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 60 ℃;

(2) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 8h, discharging and air cooling;

through sampling inspection, the mechanical property detection result of the aluminum alloy prepared by the experimental method is as follows:

as-cast state: the room temperature strength reaches 235MPa, the fracture elongation reaches 2.8 percent, and the Brinell Hardness (HBS) is 90;

heat treated state (T6): the strength reaches 430MPa, the fracture elongation reaches 4 percent, and the Brinell Hardness (HBS) is 130.

Example 4

(1) According to the mass percentage of alloy elements in the aluminum-silicon alloy, Si: 11%, Cu: 3.20%, Mg: 0.35%, Zr: 0.25%, Sr: 0.04%, Mn: 0.14%, Zn: 0.2 percent of Fe, 0.2 percent of Al and trace inevitable impurities, and respectively weighing industrial Si, Al-50 percent of copper, magnesium ingot, Al-5 percent of Zr, Al-10 percent of Mn and Al-10 percent of Sr intermediate alloy; wherein the industrial Si has a particle size of 1-3cm³Block-shaped;

(2) weighing a non-toxic refining agent (TR-L) according to 0.3 percent of the total feeding weight in the step (1);

(3) putting the industrial Si, Al-50% of copper, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, aluminum ingot and sodium-free refining agent in the steps (1) and (2) into a constant-temperature preheating drying furnace at the temperature of 200 ℃ for drying for 2 hours;

(4) putting the industrial silicon and aluminum ingots dried in the step (3) into an industrial electric furnace, and setting the furnace temperature of the industrial electric furnace to 950 ℃;

(5) electrifying for 3.5h, stirring the molten aluminum in the furnace for 15min after remelting in the furnace uses aluminum ingots and industrial silicon to be completely melted, then adding half of the nontoxic refining agent weighed in the step (1), stirring and standing for 10min, and skimming.

(6) Adding the intermediate alloy of Al-50% of copper, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr dried in the step (3) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 25 min;

(7) and (3) when all materials in the furnace are completely melted down, adjusting the temperature to 760 ℃, preserving the heat for 20min, adding the rest non-toxic refining agent, stirring and standing for 10min, and skimming slag.

(8) Pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely melted, and rapidly stirring for 5 min;

(9) through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

(10) introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 10min, standing for 10min, and skimming;

(11) adjusting the temperature of the aluminum alloy melt, and tapping and casting at 715 ℃ to obtain the near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

In this example 2, the non-toxic refining agent is a sodium-free high-efficiency degassing and deslagging refining agent manufactured by Xuzhou Huazhong aluminum industry.

When the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in the embodiment 2 is used for preparing a casting, a heat treatment process is performed according to the following steps:

(1) the casting is placed in an industrial aluminum alloy heat treatment furnace, and the two-step solid solution treatment is implemented, and the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 45 ℃;

(2) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 10h, discharging and air cooling;

through sampling inspection, the mechanical property detection result of the aluminum alloy prepared by the experimental method is as follows:

as-cast state: the room temperature strength reaches 245MPa, the Brinell Hardness (HBS) is 89, and the fracture elongation reaches 3.4%;

heat treated state (T6): the tensile strength at room temperature reaches 435MPa, the Brinell Hardness (HBS) is 128, and the fracture elongation reaches 3.8%;

comparative example

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

It can be seen that the as-cast state and heat treatment state mechanics of the alloy of the invention are obviously superior to those of ZL111 aluminum alloy, which shows that the alloy material of the invention has more excellent tensile strength and toughness strength.

TABLE 1 comparison table of performance tests of alloy material of the present invention and ZL111 aluminum alloy

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting the protection scope thereof, and although the present application is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: numerous variations, modifications, and equivalents will occur to those skilled in the art upon reading the present application and are within the scope of the claims as issued or as granted.

Claims (4)

1. The high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy is characterized in that the near-eutectic aluminum-silicon-copper-magnesium alloy is prepared by the following steps of preparing the following elements in percentage by mass,

the following elements in percentage by mass are as follows:

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 tensile strength of the alloy at room temperature in the as-cast state is 215-245MPa, and the fracture elongation is 2-3.5%;

the preparation process comprises the following steps:

drying raw materials in the step (1): respectively weighing the particles with a particle size of 1-3cm³Massive industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr intermediate alloy; then weighing a non-toxic refining agent according to 0.3 percent of the total feeding weight of the raw materials; putting the weighed industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, refining agent and aluminum ingot into a constant-temperature preheating drying furnace at 200 ℃ for drying for 1.5-2 h;

melting in step (2): placing the industrial silicon and aluminum ingots dried in the step (1) in an industrial electric furnace, and setting the furnace temperature to 850-; stirring the molten aluminum in the furnace for 10-15min after the remelting aluminum ingot and the industrial silicon in the furnace are completely melted, then adding 50% of the total amount of the non-toxic refining agent preheated and dried in the step (1), stirring, standing for 5-10min, and skimming;

smelting in step (3): adding the intermediate alloy of Al-50% Cu, Al-5% Zr, Al-10% Mn and Al-10% Sr dried in the step (1) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃; after all the materials in the furnace are completely melted down, adjusting the temperature to 750-775 ℃, preserving the heat for 15-25min, adding the remaining non-toxic refining agent in the step (2), stirring and standing for 5-10min, and skimming; adding the dried and preheated magnesium ingot in the step (1), pressing the magnesium ingot into the aluminum alloy melt until the magnesium ingot is completely melted, and slightly stirring for 5 min;

and (4) detecting: through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

refining in step (5): introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 5-10min, standing for 5-10min, and skimming;

step (6) casting: adjusting the temperature of the aluminum alloy melt, tapping and casting at 710 +/-10 ℃, thus obtaining the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

2. The high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy according to claim 1, characterized in that when the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy material obtained in claim 1 is used for preparing castings, the heat treatment process is carried out according to the following steps:

solution treatment: placing the casting in an industrial aluminum alloy heat treatment furnace, and implementing two-step solid solution treatment, wherein the specific process comprises the following steps: keeping the temperature at 500 ℃ for 4h, then heating to 515 ℃ and keeping the temperature for 8h, and quickly quenching into water at 40-60 ℃;

and (3) cooling after heat preservation: and (3) placing the casting in an aluminum alloy aging furnace, keeping the temperature at 175 ℃ for 8-12h, discharging and air cooling.

3. The Al-Si-Cu-Mg alloy with high toughness and near eutectic crystal property as claimed in claim 2, wherein the alloy has a room temperature tensile strength of 410-440MPa and a fracture elongation of 3.5-4.5% in the heat treated state.

4. The preparation method for preparing the high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy according to claim 1 is characterized by comprising the following steps:

drying raw materials in the step (1): respectively weighing the particles with a particle size of 1-3cm³Massive industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn and Al-10% of Sr intermediate alloy; then weighing a non-toxic refining agent according to 0.3 percent of the total feeding weight of the raw materials; putting the weighed industrial silicon, Al-50% of Cu, magnesium ingot, Al-5% of Zr, Al-10% of Mn, Al-10% of Sr intermediate alloy, refining agent and aluminum ingot into a constant-temperature preheating drying furnace at 200 ℃ for drying for 1.5-2 h;

melting in step (2): placing the industrial silicon and aluminum ingots dried in the step (1) in an industrial electric furnace, and setting the furnace temperature to 850-; electrifying for 3-4h, stirring the molten aluminum in the furnace for 10-15min after remelting in the furnace uses aluminum ingots and industrial silicon to be completely melted, then adding 50% of the total amount of the part of the non-toxic refining agent preheated and dried in the step (1), stirring, standing for 5-10min, and skimming;

smelting in step (3): adding intermediate alloys of Al-50% Cu, Al-5% Zr, Al-10% Mn and Al-10% Sr dried in the step (1) into an industrial electric furnace, and setting the temperature of the melt in the furnace to be 800 ℃ and keeping the temperature for 20-30 min; after all the materials in the furnace are completely melted down, adjusting the temperature to 750-770 ℃, preserving the heat for 15-20min, adding the remaining non-toxic refining agent in the step (2), stirring and standing for 5-10min, and skimming; adding the dried and preheated magnesium ingot in the step (1), pressing the magnesium ingot into the aluminum alloy melt by using a bell jar until the magnesium ingot is completely molten, and slightly stirring for 5 min;

and (4) detecting: through rapid sampling in front of the furnace and characteristic parameter measurement in the solidification process, the qualified components, the deterioration of eutectic Si and the refinement of aluminum phase are determined to meet the requirements;

refining in step (5): introducing nitrogen into the aluminum alloy melt, further refining, controlling the introduction time to be 5-10min, standing for 5-10min, and skimming;

step (6) casting: adjusting the temperature of the aluminum alloy melt, tapping and casting at 710 +/-10 ℃, thus obtaining the high-strength and high-toughness near-eutectic aluminum-silicon-copper-magnesium alloy as-cast material.

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