KR20240121707A - Non-heat-treatable high-strength die-cast silicon aluminum alloy and its manufacturing method - Google Patents

Abstract

The present invention relates to a non-heat-treatable high-toughness die-cast silicon aluminum alloy and a manufacturing method therefor. The alloy according to the present invention effectively suppresses the negative influence caused by the Fe element through controlling a constant Mn/Fe ratio, effectively refines the Si in the material while introducing a constant ratio of rare earth elements, and forms a high-temperature phase with elements such as Al and Cu, thereby improving the deformation resistance of the die-cast integral large structure. Under the die-casting condition of large casting physical sampling, the alloy can reach a tensile strength of 290 MPa, a yield strength of 140 MPa, and an elongation of 13%, and also has excellent die-casting forming performance, and the energy used is environmentally friendly energy and can meet the low-carbon emission standard.

Description

Non-heat-treatable high-strength die-cast silicon aluminum alloy and its manufacturing method

Cross-citation of related applications

This application was filed on December 10, 2021, and the application number is 202111507879.5, and the priority of the Chinese patent application entitled "Non-heat treatable high-toughness die-cast silicon aluminum alloy and its manufacturing method" is incorporated herein by reference in its entirety.

Technical field

The present invention relates to metal material technology, and more particularly, to a non-heat-treatable high-strength die-cast silicon aluminum alloy and a method for producing the same.

With the promotion of carbon peak and carbon neutralization policies, carbon emission indicators are gradually adjusted downward, the advantages of low energy consumption of recycled aluminum are highlighted, and the trend of "price rises with electricity" in the aluminum industry is broken, and the recycled aluminum industry, as a leading industry, is more conducive to the healthy, stable and sustainable development of the aluminum industry. The carbon emissions of recycled aluminum are significantly less than those of thermal electrolytic aluminum. 1 ton of thermal power can electrolyze 12 tons of virgin aluminum emissions, and the production of 1 ton of recycled aluminum only emits 300 kg of carbon dioxide, and the production of 1 ton of recycled aluminum saves 3.4 tons of standard coal, saves 14 m³ of water, and reduces 20 tons of solid waste emissions. Calculating that 1 ton of standard coal emits 3 tons of carbon dioxide, and adding the carbon emissions of other auxiliary materials, 1 ton of recycled aluminum can reduce a total of about 11.5 tons of carbon dioxide emissions, and recycled aluminum also has obvious economic effects. The production of raw aluminum involves the mining of bauxite, long-distance transportation, etc., while the production of aluminum oxide and thermal electrolytic aluminum consumes huge energy. Compared with the production of raw aluminum, the production of recycled aluminum has a relatively low cost. With the rapid increase of the social reserve of waste aluminum in China and the gradual improvement of the waste resource recovery system, the price of waste aluminum is expected to further decline. Compared with the cost of thermal electrolytic raw aluminum, the production of recycled aluminum has an even more obvious cost advantage. In addition, if raw aluminum is electrolyzed with environmentally friendly energy, there will be no carbon dioxide emissions. Environmentally friendly energy includes hydropower, wind power, and photovoltaic energy.

In recent years, with the emergence and development of new energy vehicles, new energy vehicles powered by batteries are subject to the constraints of battery weight and power battery driving range, and due to the automobile energy conservation and pollutant emission reduction policies, the design and selection of raw materials of vehicles require more urgent weight reduction compared with traditional vehicles. Aluminum alloy is one of the lightweight materials, and has comparative advantages in terms of technical application, operational safety and recyclability, so aluminum alloy is gradually replacing steel in the automobile industry, and die casting forming technology is widely applied in the production of automobile parts.

The automotive and aerospace industries have strict requirements for parts, and they require good impact toughness and high elongation when raw materials are deformed. In response, the automotive industry has put forward the requirements that the tensile strength of aluminum alloy die castings should be greater than 180MPa, the yield strength should be greater than 120MPa, and the elongation should be greater than 10% for large-scale integral body structures. Although traditional Al-Si alloys have excellent strength and casting performance, their plasticity and elongation are relatively low, and the raw materials cannot meet the requirements of large-scale integral molded pressurized structures of automobiles. In recent years, in order to meet the needs of the automobile market, the development of high-toughness aluminum alloys has received more and more attention. For example, the Silafont-36 alloy (Patent Publication No.: US 6364970B1) developed by German RWE has an elongation of no more than 6% at room temperature, a tensile strength of about 210 MPa, a yield strength of 140 MPa, and an elongation of 15% after long-term T7 heat treatment, which can meet the requirements of automobile parts. However, the process has low production efficiency, complicated heat treatment technology, difficult control of the heat treatment process, and high heat treatment cost. As another example, the non-heat-treatable strengthened high-strength and high-toughness die-cast Al-Mg-Si alloy (Patent Publication No.: CN 108754256A) developed by Shanghai Jiao Tong University has relatively good mechanical properties of the alloy, but the Al-Mg-Si alloy has poor castability, and the high magnesium content easily causes heating loss, high viscosity of the aluminum liquid, high shrinkage rate, and erosion of the die-casting model to reduce the service life of the model, so it is not suitable for use as large body structures. The non-heat-treatable self-strengthening silicon aluminum alloy (Patent Publication No.: CN 104831129A) developed by Fengyang Irons and Shanghai Jiaotong University has relatively high control over impurity elements, cannot be produced by waste aluminum, and cannot meet the demands of future carbon peak and carbon neutralization context, and the elongation of precision die-casting castings is about 7.5%, which cannot meet the high toughness requirement of current large-sized car body structures. The high-strength and high-toughness die-cast aluminum alloy (Patent Publication No.: CN 109881056A) developed by Shanghai Yongmaotai Automobile Parts and Shanghai Jiaotong University has good castability, but the elongation of the alloy in the non-heat-treated state of die-casting is only 7%, which cannot meet the high toughness requirement of car structures. The high-toughness die-cast aluminum alloy (Patent Publication No.: CN 106636787A) developed by Suzhou Huichi Alloy has excellent castability and strength, but the requirement for the impurity element content is less than 0.005%, which has a very high requirement for the impurity content, cannot be produced by adding waste aluminum, and the elongation of the casting in the non-heat-treated state can only reach 9.7%, which cannot meet the high-toughness requirement of large-scale die-cast integral parts.

The content section of the present invention is provided to briefly introduce the concept. The concept will be described in detail through the specific embodiments section described below. The content section of the present invention is not intended to specify the critical features or necessary features of the technical solution requiring protection, and is not intended to limit the scope of the technical solution seeking protection.

The present invention provides a non-heat-treatable high-strength die-cast silicon aluminum alloy and a method for producing the same. The present invention reduces carbon emissions in the production process and can achieve an elongation of 11% to 16% without a heat treatment process.

First, an embodiment of the present invention is a non-heat-treatable high-strength die-cast silicon aluminum alloy, wherein the composition of each component in the die-cast silicon aluminum alloy based on the total weight of the alloy is as follows.

Si: 6.3-8.3%, Fe: 0.07-0.45%, Cu: 0.05-0.5%, Mn: 0.5-0.8%, Mg: 0.15-0.35%, Ti: 0.01-0.2%, Sr: 0.015-0.035%. Total rare earth: 0.04%-0.2%, rare earths include one or more of La/Ce/Sc. Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, the total amount of other impurities is not more than 0.2%, the remainder is Al.

The composition of each component among the selectable die-cast silicon aluminum alloys is as follows.

Si: 6.3-7.0%, Fe: 0.2-0.4%, Cu: 0.35-0.45%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.1-0.2%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth includes one or more of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is 0.2% or less, the remainder is Al.

The composition of each component among the selectable die-cast silicon aluminum alloys is as follows.

Si: 6.4-7.1%, Fe: 0.10-0.25%, Cu: 0.05-0.28%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.03-0.16%, Sr: 0.025-0.035%, Total rare earth: 0.04%-0.15%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is 0.2% or less, the remainder is Al.

The composition of each component among the selectable die-cast silicon aluminum alloys is as follows.

Si: 7.0-7.7%, Fe: 0.15-0.3%, Cu: 0.2-0.35%, Mn: 0.6-0.8%, Mg: 0.2-0.3%, Ti: 0.05-0.2%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth includes one or more of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is less than 0.2%, the remainder is Al.

The composition of each component among the selectable die-cast silicon aluminum alloys is as follows.

Si: 7.7-8.3%, Fe: 0.07-0.2%, Cu: 0.05-0.2%, Mn: 0.6-0.8%, Mg: 0.15-0.3%, Ti: 0.01-0.15%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is less than 0.2%, the remainder is Al.

The tensile strength of the optional die-cast silicon aluminum alloy is 270Mpa or more, the yield strength is 130Mpa or more, and the elongation is 11%.

Second, an embodiment of the present invention provides a craft method for manufacturing the die cast silicon aluminum alloy described above, and the method is as follows.

The various raw materials that are not easily subjected to heating loss, which are used in the production of the above-described die-cast silicon-aluminum alloy, are heated and melted to produce aluminum liquid, and after the aluminum liquid is subjected to slag removal and refining treatment, various raw materials that are subjected to heating loss are added, and after the components reach the standard, the above-described die-cast silicon-aluminum alloy is obtained through casting treatment.

In addition, it also includes die casting molding of the above-mentioned die cast silicon aluminum alloy. The die casting molding temperature of the above-mentioned die cast silicon aluminum alloy is 680-720℃, the die casting speed is 2.5-5m/s, the heat preservation time is 2-10s, and a die casting in a non-heat treatment state is obtained.

In addition, after all raw materials are completely melted, the aluminum alloy solution described above is uniformly stirred and allowed to stand, then sampling analysis is performed and the required element content is adjusted according to the component requirement standards.

Additionally, the refining agent used does not contain Na ions.

The present invention provides a non-heat-treatable high-toughness die-cast aluminum silicon alloy and a method for producing the same. The aluminum alloy produced by the present invention can be produced from scrap aluminum without the condition that the T7 heat treatment of traditional die-cast aluminum alloys can only meet the characteristics required for automobile body structures, thereby reducing carbon emissions generated during the production process, and the elongation can reach 11-16% without a heat treatment process.

Both the above description and the detailed description below are intended to provide specific descriptions of the invention creations for which protection is claimed, by way of example only.

The above-described features and other features and advantages of each embodiment are further clarified by combining the drawings and the following examples with reference to them. The same or similar drawing notations in the drawings represent the same or similar elements. The drawings are for illustration purposes only, and the original and the elements may not be drawn to scale.
Figure 1 is a micro-structure metallographic diagram of a die-cast aluminum alloy obtained in Example 2 of the present invention, among which Figure (a) is a 100X micro-structure metallographic diagram, and Figure (b) is a 500X micro-structure metallographic diagram.
Figure 2 is a die-cast aluminum alloy fluidity test mold obtained in Example 2.
Figure 3 is a graph showing the tensile stress strain of die-cast aluminum alloys obtained in Example 2, Comparative Examples 1 and 2.

The present disclosure will be described in more detail with reference to the attached drawings. Although some embodiments disclosed through the attached drawings are shown, it should be understood that the present disclosure can be implemented in various ways and is not limited to the described embodiments. On the contrary, the purpose of providing the embodiments is to more completely understand the present disclosure. In addition, it should be understood that the attached drawings and embodiments shown in the present disclosure are only exemplary and are not intended to limit the scope of protection of the present disclosure.

The steps described in the method of implementing the present disclosure may be performed in a different order and/or in parallel. In addition, the method of implementing the method may include additional steps and/or steps that are performed by omitting them. The scope of the present disclosure is not limited thereto.

The present disclosure provides a non-heat-treatable high-strength die-cast silicon aluminum alloy and a method for producing the same. The following is a description of embodiments of the present disclosure in combination with the accompanying drawings.

Example 1

The composition of each component of the low-carbon emission, renewable, non-heat-treatable, high-toughness die-cast silicon aluminum alloy of the present embodiment is as follows: Mg: 0.2%, Si: 6.5%, Fe: 0.15%, Cu: 0.1%, Mn: 0.5%, Ti: 0.03%, Sr: 0.025%, total amount of La、Ce: 0.05%, Ni: 0.005%, Zn: 0.006%, Ga: 0.015%, remaining impurities of 0.2% or less, and the remainder is aluminum.

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot into the furnace and melt it, and set the melting temperature to 760-790℃. After the aluminum ingot is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga to refine it.

(4) Refining, slag removal: The aluminum alloy molten material is stirred uniformly at a temperature of 740 to 760°C, and a special refining agent for aluminum alloy is added to perform primary and secondary refining. The two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Example 2

The composition of each component of the low-carbon emission, renewable, non-heat-treatable, high-toughness die-cast silicon aluminum alloy of the present embodiment is as follows: Mg: 0.3%, Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Ti: 0.07%, Sr: 0.02%, La: 0.1%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%, the remaining impurities are 0.2% or less, and the remainder is aluminum.

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot or waste aluminum, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot or waste aluminum into the furnace and melt it, and set the melting temperature to 760-790℃. After the aluminum ingot or waste aluminum is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga to refine it.

(4) Refining, slag removal: The aluminum alloy molten material is stirred uniformly at a temperature of 740 to 760°C, and a special refining agent for aluminum alloy is added to perform primary and secondary refining. The two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Example 3

The composition of each component of the low-carbon emission, renewable, non-heat-treatable, high-toughness die-cast silicon aluminum alloy of the present embodiment is as follows: Mg: 0.35%, Si: 7.5%, Fe: 0.25%, Cu: 0.3%, Mn: 0.7%, Ti: 0.15%, Sr: 0.03%, Ce: 0.08%, Ni: 0.08%, Zn: 0.09%, Ga: 0.025%, , the remaining impurities are less than 0.2%, and the remainder is aluminum.

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot or waste aluminum, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot or waste aluminum into the furnace and melt it, and set the melting temperature to 760-790℃. After the aluminum ingot or waste aluminum is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga to refine it.

(4) Refining, slag removal: The aluminum alloy molten material is stirred uniformly at a temperature of 740 to 760°C, and a special refining agent for aluminum alloy is added to perform primary and secondary refining. The two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Example 4

The composition of each component of the low-carbon emission, renewable, non-heat-treatable, high-toughness die-cast silicon aluminum alloy of the present embodiment is as follows: Mg: 0.25%, Si: 7.8%, Fe: 0.35%, Cu: 0.4%, Mn: 0.8%, Ti: 0.2%, Sr: 0.035%, Sc: 0.15%, Ni: 0.02%, Zn: 0.08%, Ga: 0.012%, the remaining impurities are 0.2% or less, and the remainder is aluminum.

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot or waste aluminum, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot or waste aluminum into the furnace and melt it, and set the melting temperature to 760-790℃. After the aluminum ingot or waste aluminum is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga to refine it.

(4) Refining, slag removal: The aluminum alloy molten material is stirred uniformly at a temperature of 740 to 760°C, and a special refining agent for aluminum alloy is added to perform primary and secondary refining. The two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Example 5

The composition of each component of the low-carbon emission, renewable, non-heat-treatable, high-toughness die-cast silicon aluminum alloy of the present embodiment is as follows: Mg: 0.15%, Si: 8.3%, Fe: 0.45%, Cu: 0.5%, Mn: 0.65%, Ti: 0.15%, Sr: 0.03%, total amount of La and Sc: 0.2%, Ni: 0.08%, Zn: 0.01%, Ga: 0.018%, remaining impurities of 0.2% or less, the remainder being aluminum.

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot or waste aluminum, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot or waste aluminum into the furnace and melt it, and set the melting temperature to 760-790℃. After the aluminum ingot or waste aluminum is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga to refine it.

(4) Refining, slag removal: The aluminum alloy molten material is stirred uniformly at a temperature of 740 to 760°C, and a special refining agent for aluminum alloy is added to perform primary and secondary refining. The two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Example 6

The method for manufacturing the low-carbon emission, regenerable, non-heat treatable, high-strength die-cast silicon aluminum alloy of the present embodiment is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: After the recovered waste aluminum is classified, selected, and processed, the materials for each element of the aluminum alloy are prepared, such as metal Al ingot, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc., according to the alloy composition ratio, and after considering the appropriate heating loss, they are added according to the ratio of the alloy composition.

(3) Putting into the furnace and refining: First, put 40% metal Al ingot and 60% waste aluminum in sequence into the furnace for refining, and set the refining temperature to 760-790℃. After complete melting, perform sampling analysis, and add other elements according to the ratio. Increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga for refining.

(4) Refining, slag removal: The aluminum alloy melt whose components meet the standards is stirred uniformly at a temperature of 740 to 760℃, and a special refining agent for aluminum alloy is added to perform the first and second refining, and the two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: The final weight ratio is Mg: 0.25%, Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Ti: 0.12%, Sr: 0.028%, La, Ce, Sc total: 0.2%, Ni: 0.005%, Zn: 0.06%, Ga: 0.02%, and the remaining impurities are less than 0.2%, and the remainder is aluminum. After passing the full component analysis of the melting furnace, the ingot is cast into a finished product under the casting temperature, or high-pressure casting is performed by die casting technique to obtain a die casting in a non-heat-treated state.

Example 7

The method for manufacturing a low-carbon emission, recyclable, non-heat treatable, high-strength die-cast silicon aluminum alloy from waste aluminum of the present invention is as follows.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Material: After the recovered waste aluminum has gone through a classification selection process, metal Mg ingot, industrial Si, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn and metal Ga, Al-Sr intermediate alloy, aluminum rare earth intermediate alloy, etc. are prepared as materials for each element of the aluminum alloy according to the alloy component ratio, and after considering appropriate heating loss, they are added according to the ratio of the alloy component.

(3) Putting into the furnace and refining: Put 100% of waste aluminum into the furnace and refining, and set the refining temperature to 760-790℃. After complete melting, perform sampling analysis, and add other elements according to the required ratio. Increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, metal Ga, and refining.

(4) Refining, slag removal: The aluminum alloy melt whose components meet the standards is stirred uniformly at a temperature of 740 to 760℃, and a special refining agent for aluminum alloy is added to perform the first and second refining, and the two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, aluminum rare earth intermediate metal, metal Mg, and Al-Sr intermediate alloy ingot are added to the furnace, and after refining and modification treatment, aluminum alloy molten metal is obtained, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: The final weight ratio is Mg: 0.3%, Si: 7.7%, Fe: 0.15%, Cu: 0.3%, Mn: 0.7%, Ti: 0.15%, Sr: 0.035%, Ce: 0.08%, Ni: 0.1%, Zn: 0.1%, Ga: 0.03%. The remaining impurities are less than 0.2%, and the remainder is aluminum. After passing the component analysis before the melting furnace, the ingot is cast into a finished product under the casting temperature, or high-pressure casting is performed by die casting technique to obtain a die casting in a non-heat-treated state.

Comparative Example 1

This comparative example is an adjustment of the components of Example 2. Compared to Example 2, the Sr element was added less and the La element was not added. The proportions of each component are as follows: Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Mg: 0.3%, Ti: 0.07%, Sr: 0.008%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The method for manufacturing the die cast aluminum alloy of this comparative example comprises the following steps.

(1) Preparation of the furnace: Clean the furnace and heat it until the furnace walls turn red. Coat all work tools with graphite powder and dry and preheat.

(2) Materials: Prepare materials for each element of the aluminum alloy, such as metal Al ingot, metal Mg ingot, industrial Si, metal Cu, Al-Mn intermediate alloy or metal Mn, metal Fe, Al-Ti intermediate alloy, Al-Sr intermediate alloy, etc., and add them according to the ratio of the alloy components after considering appropriate heating loss.

(3) Putting into the furnace and melting: First, put the metal Al ingot into the furnace and melt it, and set the melting temperature to 670-690℃. After the aluminum ingot is completely melted, increase the temperature to 760-780℃, and then add industrial silicon, metal Fe, metal Cu, Al-Mn intermediate alloy or metal Mn to refine it.

(4) Refining, slag removal: The aluminum alloy melt whose components meet the standards is stirred uniformly at a temperature of 740 to 760℃, and a special refining agent for aluminum alloy is added to perform the first and second refining, and the two refinings are performed 50 to 60 minutes apart, and the slag is removed after each refining to remove the solvent and slag on the liquid surface.

(5) Addition of other metal elements: When the solution temperature is 740 to 760℃, Al-Ti intermediate alloy, metal Mg, and Al-Sr intermediate alloy ingots are added to the furnace and refined to obtain aluminum alloy molten metal, and then sampling analysis is performed.

(6) Exhaust inside the furnace. The refining temperature is maintained at 740~760℃ and exhaust inside the furnace is performed using nitrogen. The exhaust time is approximately 30~50 minutes and is left for 15~30 minutes.

(7) Casting or die casting: After passing the full component analysis of the furnace, the ingot is cast into a finished product under the casting temperature or high-pressure casting is performed using the die casting technique to obtain a die casting in a non-heat-treated state.

Comparative Example 2

This comparative example is an adjustment of the components of Example 2. Compared to Example 2, Sr element was added and La element was not added, and the ratio of each component was Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Mg: 0.3%, Ti: 0.07%, Sr: 0.05%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 3

This comparative example is an adjustment of the components of Example 6. Compared to Example 6, La, Ce, Sc, Zn, Ni, and Ga elements were not added, and the proportions of each component were Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, and Sr: 0.028%. The remaining amount of other impurities was 0.2% or less, and the remainder was aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 4

This comparative example is an example in which the components of Example 6 are adjusted. Compared to Example 6, La, Ce, and Sc elements were not added, and the proportions of each component are Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 5

This comparative example is an adjustment of the components of Example 6, and compared to Example 6, high contents of La, Ce, and Sc elements were added, and the proportions of each component were Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 0.2, Ce: 0.2, Sc: 0.2, Ni: 0.06%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 6

This comparative example is an adjustment of the components of Example 6. Compared to Example 6, a high content of La element was added, and the ratio of each component is Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 1.0, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 7

This comparative example is an adjustment of the components of Example 6. Compared to Example 6, a high content of Sc element was added, and the ratio of each component was Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, Sc: 0.5, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%. The remaining amount of other impurities was 0.2% or less, and the remainder was aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Comparative Example 8

This comparative example is an adjustment of the components of Example 6. Compared to Example 6, a high content of Sc element was added, and the ratio of each component was Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 0.01, Sc: 0.01, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%. The remaining amount of other impurities is 0.2% or less, and the remainder is aluminum.

The manufacturing method of this comparative example is the same as that of Comparative Example 1.

Table 1 shows the aluminum alloy components of Examples 1 to 7 and Comparative Examples 1 to 8.

Table 2 shows the mechanical properties and fluidity at room temperature after being sampled in the F state of the aluminum alloy casting bodies obtained in Examples 1 to 7 and Comparative Examples 1 to 8 and after being kept at a temperature of 180°C for 30 minutes.

As shown in Tables 1 and 2, the Sr element content of Comparative Example 1 is much lower than that of Example 2, and furthermore, when rare earth elements were not added, the yield strength decreased by 26 MPa and the elongation decreased by 4.2%. Compared with Example 2, the Sr element content of Comparative Example 2 is much higher than that of Example 2, and furthermore, when rare earth elements were not added, the yield strength decreased by 17 MPa and the elongation decreased by 4.9%. Compared with Example 6, the yield strength of Comparative Example 3 decreased by 25 MPa and the elongation decreased by 3.3% when rare earth elements, n, Ni, and Ga were not added. Compared with Example 6, the yield strength of Comparative Example 4 decreased by 23 MPa and the elongation decreased by 3.6% when rare earth elements were not added. Compared to Example 6, in Comparative Example 5, when the total amount of added rare earth elements La, Ce, and Sc was 0.6%, the yield strength decreased by 18 MPa and the elongation decreased by 4.8%. Compared to Example 6, in Comparative Example 6, when the added rare earth element La was 1.0%, the yield strength decreased by 16 MPa and the elongation decreased by 5.1%. Compared to Example 6, in Comparative Example 7, when the added rare earth element Sc was 0.5%, the yield strength decreased by 20 MPa and the elongation decreased by 4.1%. Compared to Example 6, in Comparative Example 8, when the added rare earth elements La and Sc were 0.02%, the yield strength decreased by 16 MPa and the elongation decreased by 4.2%. In summary of the foregoing, excellent mechanical properties can be obtained only when Sr and rare earth elements La, Ce, Sc are included in the scope of this patent, and if the content of Sr and rare earth elements La, Ce, Sc is too low or too high, the overall mechanical properties will be poor.

Although the above-described optimization implementation method of the present invention is described, the present invention is not limited to the above-described content. Within the scope of the technical idea of the present invention, various simple modifications are possible by combining the technical features of the technical solution of the present invention in any suitable manner, and such simple modifications and combinations should be regarded as public content of this patent and should fall within the protection scope of the present invention.

Claims (10)

A non-heat-treatable high-strength die-cast silicon aluminum alloy, characterized by the following composition ratios.
Si: 6.3-8.3%, Fe: 0.07-0.45%, Cu: 0.05-0.5%, Mn: 0.5-0.8%, Mg: 0.15-0.35%, Ti: 0.01-0.2%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is not more than 0.2%, the remainder is Al。 A die-cast silicon aluminum alloy according to claim 1, characterized in that the composition ratio of the die-cast silicon aluminum alloy is as follows.
Si: 6.3-7.0%, Fe: 0.2-0.4%, Cu: 0.35-0.45%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.1-0.2%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is less than 0.2%, the remainder is Al. A die-cast silicon-aluminum alloy according to claim 1, characterized in that the composition ratio of the non-heat-treatable high-toughness die-cast silicon-aluminum alloy is as follows.
Si: 6.4-7.1%, Fe: 0.10-0.25%, Cu: 0.05-0.28%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.03-0.16%, Sr: 0.025-0.035%, Total rare earth: 0.04%-0.15%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is not more than 0.2%, the remainder is Al。 A die-cast silicon aluminum alloy according to claim 1, characterized in that the composition ratio of the die-cast silicon aluminum alloy is as follows.
Si: 7.0-7.7%, Fe: 0.15-0.3%, Cu: 0.2-0.35%, Mn: 0.6-0.8%, Mg: 0.2-0.3%, Ti: 0.05-0.2%, Sr: 0.015-0.035%, Total rare earth: 0.04%-0.2%, Rare earth contains at least one of La/Ce/Sc, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, Total amount of other impurities is less than 0.2%, the remainder is Al. A die cast silicon aluminum alloy characterized in that the composition ratio of the die cast silicon aluminum alloy in claim 1 is as follows:
Si: 7.7-8.3%；Fe: 0.07-0.2%；Cu: 0.05-0.2%；Mn: 0.6-0.8%；Mg: 0.15-0.3%；Ti: 0.01-0.15%；Sr: 0.015-0.035%；Total amount of rare earth elements: 0.04%-0.2%, rare earth elements include at least one of La/Ce/Sc; Ni: 0.001-0.1%; Zn: 0.005-0.1%; Ga: 0.01-0.03%; The total amount of other impurities is not more than 0.2%, and the remainder is Al. Any die-cast silicon-aluminum alloy according to claims 1 to 5, characterized by a tensile strength of 270 MPa or more, a yield strength of 130 MPa or more, and an elongation of 11% or more. Any die-cast silicon-aluminum alloy according to claims 1 to 6, wherein the die-cast silicon-aluminum alloy has the following characteristics:
Each material having a low heating loss is melted by heating to obtain an aluminum liquid, which is used to manufacture the die-cast silicon aluminum alloy described above. Then, the aluminum liquid is subjected to slag removal and refining treatment, and each material having a low heating loss is added. After the components reach the standard, the die-cast silicon aluminum alloy described above is obtained by casting. A die-cast silicon-aluminum alloy according to claim 7, characterized in that the die-cast silicon-aluminum alloy described above is die-casted, the die-casting forming temperature of the die-cast silicon-aluminum alloy is 680-720°C, the die-casting speed is 2.5-5 m/s, and the heat-keeping time is 2-10 s to obtain a die-casting in a non-heat-treated state. A die-cast silicon aluminum alloy characterized in that, in claim 7, after each material is completely melted, the aluminum alloy liquid is uniformly stirred and allowed to stand, and then sampling analysis is performed to adjust the required element content to a standard range. A die-cast silicon aluminum alloy according to claim 7, characterized in that the refining agent does not contain Na ions.