Aluminum-silicon alloy material, aluminum-silicon alloy casting, preparation method and baking strengthening detection method

Abstract

The invention provides an aluminum-silicon alloy material, an aluminum-silicon alloy casting, a preparation method and a baking strengthening detection method. The aluminum-silicon alloy material comprises the following components in percentage by weight: 8.4%-9.0% of Si, 0.6%-0.8% of Mn, 0.05%-0.35% of Zn, 0.2%-0.3% of Mg, 0.1%-0.3% of Cu, 0.1%-0.18% of Ti, 0.01%-0.03% of V, 0.02%-0.04% of Sr, less than or equal to 0.1% of Fe, Nalt and the balance of Al. 0.004%, Blt; the aluminum alloy comprises the following components in percentage by weight: 0.002% of aluminum, 0.01-0.02% of lanthanum, 0.01-0.02% of cerium, and the balance of aluminum and inevitable impurities. Wherein Mg is beneficial to improving the hardness, strength and fatigue resistance of the aluminum-silicon alloy, Sr and Na are combined, the microstructure of the aluminum-silicon alloy can be improved, and the plasticity of the material is improved. The rare earth elements La and Ce can refine grains and improve the performance of the aluminum-silicon alloy.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy material casting, and in particular to an aluminum-silicon alloy material, an aluminum-silicon alloy casting, a preparation method and a baking strengthening detection method. Background Art

[0002] With the development of industry, the performance requirements for metal materials are getting higher and higher. Aluminum alloys are widely used in aerospace, automobile manufacturing, electronic products and other fields due to their light weight, high strength and corrosion resistance.

[0003] Among them, die-cast aluminum silicon alloy has attracted much attention due to its good casting performance and mechanical properties. In the manufacturing process of modern automobile body panels, low-temperature baking process is required to complete the paint hardening. At the same time, low-temperature baking will also increase the yield strength of the material. Traditional die-cast aluminum silicon alloy, limited by the microstructure of aluminum silicon alloy, will significantly reduce plasticity after low-temperature baking. Therefore, the performance of aluminum silicon alloy needs to be improved. Summary of the invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide an aluminum-silicon alloy material, an aluminum-silicon alloy casting, a preparation method and a baking strengthening detection method, which can improve the performance of the aluminum-silicon alloy material and enhance the plasticity of the material.

[0005] In order to achieve the above technical objectives, the technical solutions adopted in this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides an aluminum-silicon alloy material, wherein the components of the aluminum-silicon alloy material include, by specified mass percentage:

[0007] Si: 8.4-9.0%, Mn: 0.6-0.8%, Zn: 0.05-0.35%, Mg: 0.2-0.3%, Cu: 0.1-0.3%, Ti: 0.1-0.18%, V: 0.01-0.03%, Sr: 0.02-0.04%, Fe≤0.1%, Na<0.004%, B<0.002%, La: 0.01-0.02%, Ce: 0.01-0.02%, the balance is Al and unavoidable impurities.

[0008] In a second aspect, an embodiment of the present application further provides an aluminum-silicon alloy casting, which adopts the above-mentioned aluminum-silicon alloy material and obtains the aluminum-silicon alloy casting by die casting.

[0009] In a third aspect, an embodiment of the present application further provides a method for preparing an aluminum-silicon alloy casting, the method comprising:

[0010] Prepare alloy raw materials according to the ratio of each element of the above aluminum-silicon alloy material;

[0011] The die-casting equipment is controlled to operate according to specified parameters, and the alloy raw material is die-cast to obtain an aluminum-silicon alloy casting.

[0012] In conjunction with the third aspect, in some optional embodiments, the specified parameters include melt temperature, mold temperature, high speed, low speed, high speed position, boost position, boost pressure and vacuum degree of the die-casting equipment;

[0013] Control die casting equipment to run according to specified parameters, including:

[0014] Controlling the pouring temperature of the die-casting equipment to be 670-730°C;

[0015] Controlling the die temperature of the die-casting equipment to be 170-230°C;

[0016] Control the high speed of the die-casting equipment to be 2.5-3.5 m / s;

[0017] Control the low speed of the die-casting equipment to 0.15-0.35 m / s;

[0018] Control the high speed position of the die casting equipment to 240-280 mm;

[0019] Controlling the boost position of the die-casting equipment to be 260-300 mm;

[0020] Controlling the casting pressure of the die-casting equipment to be 65-95 MPa;

[0021] The vacuum degree of the die-casting equipment is controlled to be 20-1000 mbr.

[0022] In combination with the third aspect, in some optional embodiments, the pouring temperature is 700-710°C; the mold temperature is 230°C; the high speed is 3.0m / s, the low speed is 0.25m / s; the high speed position is 260mm; the boost position is 280mm; the casting pressure is 80-90MPa; the vacuum degree is 40mbar, and the die-casting equipment has a mold retention time of 10s.

[0023] In a fourth aspect, the present application also provides a baking hardening detection method for alloy castings, the method comprising:

[0024] The alloy casting is baked and strengthened according to the specified baking conditions, wherein the alloy casting includes an aluminum-silicon alloy casting obtained by the method provided by the third aspect above;

[0025] Obtaining a first performance parameter of the alloy casting before baking, and a second performance parameter of the alloy casting after baking and strengthening;

[0026] Based on the first performance parameter and the second performance parameter, a detection result of the alloy casting is determined according to a preset detection rule, and the detection result includes an equivalent strengthening value of the alloy casting.

[0027] In conjunction with the fourth aspect, in some optional implementations, the alloy casting is subjected to baking strengthening according to a specified baking condition, including:

[0028] Baking the alloy casting at a first specified temperature and continuously baking for a first specified time;

[0029] After the first designated time period is completed, the alloy casting is baked at a second designated temperature and the baking is continued for the second designated time period, wherein the first designated temperature is 160-190°C and the second designated temperature is 125-155°C.

[0030] In combination with the fourth aspect, in some optional embodiments, the first designated temperature is 170° C., and the first designated time is 20 minutes; the second designated temperature is 145° C., and the second designated time is 40 minutes.

[0031] In conjunction with the fourth aspect, in some optional embodiments, the first performance parameter includes the yield strength σ of the alloy casting s , tensile strength σ b and elongation δ and work hardening exponent n;

[0032] The second performance parameter includes the ultimate yield strength σ of the alloy casting under the kth baking condition sk , ultimate tensile strength σ bk , Final elongation δ k and the final work hardening index n k .

[0033] In conjunction with the fourth aspect, in some optional implementations, based on the first performance parameter and the second performance parameter, according to a preset detection rule, determining the detection result of the alloy casting includes:

[0034] Based on the first performance parameter and the second performance parameter, determining a strengthening value and / or a weakening value of the corresponding parameter;

[0035] Based on the strengthening value and / or weakening value of the corresponding parameter, an equivalent strengthening value is determined to obtain the detection result.

[0036] In conjunction with the fourth aspect, in some optional implementations, determining a strengthening value and / or weakening value of a corresponding parameter based on the first performance parameter and the second performance parameter includes:

[0037] Using H1=σ sk -σs , determine the yield strength value H1, where σ sk Refers to the ultimate yield strength in the second performance parameter, σ s Refers to the yield strength among the first performance parameters;

[0038] Using H2=σ bk -σ b , determine the tensile strength value H2, where σ bk Refers to the ultimate tensile strength in the second performance parameter, σ b Refers to the tensile strength among the first performance parameters;

[0039] Using H3=δ k -δ, determine the plastic weakening value H3, where δ k refers to the final elongation in the second performance parameter, and δ refers to the elongation in the first performance parameter.

[0040] In conjunction with the fourth aspect, in some optional implementations, determining the equivalent strengthening value based on the strengthening value and / or weakening value of the corresponding parameter includes:

[0041] The equivalent strengthening value is determined based on a preset formula, wherein the preset formula is:

[0042]

[0043] In the formula, ΔH k is the equivalent strengthening value corresponding to the kth baking condition; H 1k is the yield hardening value corresponding to the kth baking condition, B is the material constant of the alloy casting before baking, and B k is the material constant corresponding to the kth baking condition, H 3k is the plastic weakening value corresponding to the kth baking condition; n refers to the work hardening index of the alloy casting before baking; n k refers to the work hardening index corresponding to the kth baking condition; δ refers to the elongation of the alloy casting before baking; δ k Refers to the final elongation corresponding to the kth baking condition.

[0044] In conjunction with the fourth aspect, in some optional implementations, the method further includes:

[0045] Based on the work hardening constitutive relationship, the first performance parameter and the second performance parameter, a stress-strain curve for describing the tensile stress of the alloy casting is established by fitting, wherein the work hardening constitutive relationship is:

[0046] σ=A+Bε n

[0047] In the formula, σ is the stress of the alloy casting, A is the preset constant term coefficient, B is the material constant of the alloy casting, ε is the strain of the alloy casting, and n is the work hardening index of the alloy casting before baking.

[0048] In conjunction with the fourth aspect, in some optional implementations, the method further includes:

[0049] When the equivalent strengthening value is not within the preset range of qualified characterization, an alarm is issued, and / or the parameters corresponding to the specified baking conditions are adjusted, and the alloy casting is baked and strengthened according to the specified baking conditions after the parameters are adjusted.

[0050] The invention adopting the above technical solution has the following advantages:

[0051] In the technical solution provided in this application, the addition of Mn element can reduce the needle-shaped β-Al5FeSi phase in the solidified structure and transform it into α-Al5(Fe,Mn)3Si2, which plays a role in breaking the needle-shaped structure and refining the grains. Mg can form a hard Mg2Si phase in the alloy, thereby improving the hardness, strength and fatigue resistance of the aluminum-silicon alloy.

[0052] Combining Sr and Na, which have similar modification mechanisms, can promote each other's modification effects, extend the modification period, and overcome the shortcomings of using Sr and Na modifiers alone. Among them, Na can effectively change the growth morphology of silicon crystals, promote high branching of silicon crystals, and improve the performance of aluminum-silicon alloys; Sr can reduce the growth rate of Si, thereby improving the microstructure of aluminum-silicon alloys and improving the plasticity of the material.

[0053] The added rare earth elements La and Ce can also be added into the melt alone as refiners because of their high melting point and low solid solubility in aluminum. They can form nucleation particles to accelerate nucleation, and also form a film on the surface of the grains to hinder grain growth, thereby achieving the effect of refining the grains and improving the performance of the aluminum-silicon alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present application may be further described by the non-limiting embodiments given in the accompanying drawings. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings may be obtained based on these drawings without creative effort.

[0055] Figure 1 A schematic flow chart of a method for preparing an aluminum-silicon alloy casting provided in an embodiment of the present application.

[0056] Figure 2A schematic flow chart of a baking hardening detection method for alloy castings provided in an embodiment of the present application.

[0057] Figure 3 Schematic diagram of the mechanical property parameters of aluminum-silicon alloy before and after baking provided in the embodiment of the present application.

[0058] Figure 4 Schematic diagram of the stress-strain curve of the aluminum-silicon alloy provided in the embodiment of the present application. DETAILED DESCRIPTION

[0059] The present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that in the drawings or descriptions, similar or identical parts use the same figure numbers, and the implementation methods not shown or described in the drawings are forms known to ordinary technicians in the relevant technical field. In the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0060] First embodiment

[0061] The present application provides an aluminum-silicon alloy material. The aluminum-silicon alloy material may include the following components in specified mass percentages:

[0062] Si (silicon): 8.4-9.0%, Mn (manganese): 0.6-0.8%, Zn (zinc): 0.05-0.35%, Mg (magnesium): 0.2-0.3%, Cu (copper): 0.1-0.3%, Ti (titanium): 0.1-0.18%, V (vanadium): 0.01-0.03%, Sr (strontium): 0.02-0.04%, Fe (iron) ≤0.1%, Na (sodium) <0.004%, B (boron) <0.002%, La (lanthanum): 0.01-0.02%, Ce (cerium): 0.01-0.02%, the balance is Al (aluminum) and unavoidable impurities.

[0063] As an optional embodiment, the aluminum-silicon alloy material may include the following components in specified mass percentages:

[0064] Si: 8.5-8.9%, Mn: 0.65-0.75%, Zn: 0.1-0.30%, Mg: 0.21-0.29%, Cu: 0.15-0.25%, Ti: 0.11-0.17%, V: 0.015-0.025%, Sr: 0.025-0.035%, Fe≤0.09%, Na<0.003%, B<0.0015%, La: 0.011-0.019%, Ce: 0.011-0.019%, the balance is Al and unavoidable impurities.

[0065] In aluminum-silicon alloy materials, the specified mass percentage can be flexibly determined according to actual conditions. For example, the mass percentage of element Si can be 8.4%, 8.6%, 8.8%, 9.0%, etc.;

[0066] The mass percentage of the element Mn may be 0.6%, 0.65%, 0.7%, 0.75%, 0.8% and the like;

[0067] The mass percentage of element Zn may be 0.05%, 0.15%, 0.25%, 0.35% and the like;

[0068] The mass percentage of element Mg can be 0.2%, 0.25%, 0.3% and other values;

[0069] The mass percentage of element Cu can be 0.1%, 0.2%, 0.3% and other values;

[0070] The mass percentage of element Ti can be 0.1%, 0.15%, 0.18% and other values;

[0071] The mass percentage of element V can be 0.01%, 0.02%, 0.03% and other values;

[0072] The mass percentage of the element Sr may be 0.02%, 0.03%, 0.04%, etc.;

[0073] The mass percentage of element Fe can be 0.05%, 0.1%, etc.;

[0074] The mass percentage of element Na can be 0.002%, 0.003%, 0.0035%, etc., which is less than 0.004%;

[0075] The mass percentage of element B may be 0.001%, 0.0015%, etc., which is less than 0.002%;

[0076] The mass percentage of element La can be 0.01%, 0.015%, 0.02%, etc.;

[0077] The mass percentage of element Ce can be 0.01%, 0.015%, 0.02%, etc.;

[0078] The balance is Al and inevitable impurities.

[0079] As an optional embodiment, the composition of the aluminum-silicon alloy material can be: Si: 8.5%, Mn: 0.65%, Zn: 0.35%, Mg: 0.25%, Cu: 0.1%, Ti: 0.1%, V: 0.01%, Sr: 0.02%, Fe: 0.1%, Na: 0.003%, B: 0.001%, La: 0.01%, Ce: 0.01%, and the balance is Al and unavoidable impurities.

[0080] As an optional embodiment, the composition of the aluminum-silicon alloy material can be: Si: 9.0%, Mn: 0.8%, Zn: 0.35%, Mg: 0.3%, Cu: 0.3%, Ti: 0.18%, V: 0.03%, Sr: 0.04%, Fe: 0.05%, Na: 0.003%, B: 0.0015%, La: 0.02%, Ce: 0.02%, and the balance is Al and unavoidable impurities.

[0081] Compared with the traditional aluminum silicon alloy, in this embodiment, the aluminum silicon alloy material contains a higher mass percentage of Mn and Mg elements. The addition of Mn element is to reduce the needle-shaped β-Al5FeSi phase in the solidified structure and transform it into α-Al5(Fe,Mn)3Si2, which plays the role of interrupting the needle-shaped structure and refining the grains.

[0082] Among them, Mg can form a hard Mg2Si phase (Young's modulus is 120 GPa) in the aluminum-silicon alloy, which can improve the hardness, strength and fatigue resistance of the aluminum-silicon alloy.

[0083] In addition, the present application uses a Na and Sr composite modifier, rather than a single Na modifier. Because, although the Na modifier has a significant modification effect, low economic cost, and can effectively change the growth morphology of silicon crystals, causing silicon crystals to be highly branched, and can improve the performance of aluminum-silicon alloys, its effective modification time is relatively short, only about 30 minutes, which limits its application in industrial production.

[0084] In this embodiment, the modification effect of the Sr modifier used is long-lasting. Although the price is higher, the Sr modifier has a longer effective modification time than the Na modifier, which helps to improve production efficiency and reduce costs. The Sr modifier can support the TPRE (twin plane concave step) mechanism through the Zigzag (sawtooth) twin growth model, reduce the growth rate of Si, thereby improving the microstructure of the aluminum-silicon alloy and enhancing the plasticity of the aluminum-silicon alloy.

[0085] In addition, a single deteriorating agent has a poor effect. In this embodiment, Sr and Na, which have similar deterioration mechanisms, are combined. Their deterioration effects promote each other, which can extend the effective period of deterioration and overcome the shortcomings of using Sr and Na deteriorating agents alone.

[0086] In this embodiment, the added rare earth elements La and Ce can also be added into the melt alone as refiners because of their high melting point and low solubility in aluminum. They can form nucleation particles to accelerate nucleation and form films on the surface of grains to hinder grain growth, thereby achieving the effect of refining grains and improving the performance of aluminum-silicon alloys.

[0087] Second embodiment

[0088] Please refer to Figure 1 The present application also provides a method for preparing an aluminum-silicon alloy casting, which can be applied to a die-casting device. The die-casting device is a conventional device used for die-casting parts, which is not specifically limited here. The preparation method may include the following steps:

[0089] Step 110, preparing specified elements of an aluminum-silicon alloy material according to specified mass percentages to serve as an alloy raw material;

[0090] Step 120, controlling the die-casting equipment to operate according to specified parameters, and die-casting the alloy raw material to obtain an aluminum-silicon alloy casting.

[0091] As an example, the specified mass percentage and the specified element may be the data described in the first embodiment. For example, step 110 may be to prepare the alloy raw material according to the following composition, and the composition of the aluminum-silicon alloy material may be:

[0092] Si: 9.0%, Mn: 0.8%, Zn: 0.35%, Mg: 0.3%, Cu: 0.3%, Ti: 0.18%, V: 0.03%, Sr: 0.04%, Fe: 0.05%, Na: 0.003%, B: 0.0015%, La: 0.02%, Ce: 0.02%, and the balance is Al and inevitable impurities.

[0093] In step 120, the specified parameters may include, but are not limited to, the melt temperature, mold temperature, high speed, low speed, high speed position, boost position, boost pressure, and vacuum degree of the die casting equipment. Controlling the die casting equipment to operate according to the specified parameters may include:

[0094] Controlling the pouring temperature of the die-casting equipment to be 670-730°C;

[0095] Controlling the die temperature of the die-casting equipment to be 170-230°C;

[0096] Control the high speed of the die-casting equipment to be 2.5-3.5 m / s;

[0097] Control the low speed of the die-casting equipment to 0.15-0.35 m / s;

[0098] Control the high speed position of the die casting equipment to 240-280 mm;

[0099] Controlling the boost position of the die-casting equipment to be 260-300 mm;

[0100] Controlling the casting pressure of the die-casting equipment to be 65-95 MPa;

[0101] The vacuum degree of the die-casting equipment is controlled to be 20-1000 mbr.

[0102] In this embodiment, parameters such as pouring temperature, mold temperature, high speed, low speed, high speed position, boost position, casting pressure, vacuum degree, etc. are all common parameters during the operation of the die-casting equipment, and their meanings are not repeated here.

[0103] As an optional embodiment, the pouring temperature can be 690-720℃; the mold temperature can be 180-220℃; the high speed can be 2.8-3.2m / s; the low speed can be 0.19-0.31m / s; the high speed position can be 250-270mm; the boost position can be 280-290mm; the casting pressure can be 80-90MPa; and the vacuum degree can be 200-800mbr.

[0104] As an example, the pouring temperature may be one of: 670° C., 690° C., 700° C., 710° C., 730° C.;

[0105] The mold temperature can be one of: 170℃, 200℃, 230℃;

[0106] High speed can be one of: 2.5m / s, 3.0m / s, 3.5m / s;

[0107] The low speed can be one of: 0.15m / s, 0.25m / s, 0.35m / s;

[0108] The high speed position can be one of: 240mm, 260mm, 280mm;

[0109] The boost position can be one of: 260mm, 280mm, 300mm;

[0110] The boost pressure can be one of: 65MPa, 75MPa, 80MPa, 85MPa, 90MPa, 95MPa;

[0111] The vacuum degree can be one of: 20mbr, 40bar, 80mbr, 160mbr, 320mbr, 640mbr, 1000mbr.

[0112] According to the experiments conducted by the inventors, the above-mentioned designated parameters are all preferred choices.

[0113] As an optional embodiment, in step 120, the pouring temperature can be 700-710°C; the mold temperature can be 230°C; the high speed can be 3.0m / s, the low speed can be 0.25m / s; the high speed position can be 260mm; the boost position can be 280mm; the casting pressure can be 80-90MPa; the vacuum degree can be 40mbar, and the die retention time of the die casting equipment can be 10s. It can be understood that after experiments by the inventor, the use of the aforementioned specified parameters is conducive to obtaining the optimal material properties of the aluminum silicon alloy.

[0114] In this embodiment, after the aluminum-silicon alloy material is placed in a corresponding mold, die-casting is performed using die-casting equipment based on the aforementioned die-casting process to obtain an aluminum-silicon alloy casting.

[0115] In this embodiment, by adjusting the ratio of Al, Si and other appropriate amounts of Mn, Zn, Mg, Cu and other elements, the die-cast aluminum silicon alloy has good strength and plasticity at room temperature. In addition, by optimizing the die-casting process parameters, such as temperature, pressure, etc., the die-cast aluminum silicon alloy of this application can be quickly solidified when filling the mold, reducing the generation of pores and shrinkage cavities, improving the density of the casting, and improving the molding quality and mechanical properties of the aluminum silicon alloy.

[0116] Third embodiment

[0117] The embodiment of the present application also provides an aluminum-silicon alloy casting, which can be obtained by using the aluminum-silicon alloy material in the first embodiment and die-casting the aluminum-silicon alloy material. The die-casting method of the aluminum-silicon alloy material can adopt the preparation method in the second embodiment, or adopt other die-casting methods, which are not specifically limited here. After the aluminum-silicon alloy material is die-cast, the obtained aluminum-silicon alloy casting has the characteristics of the aluminum-silicon alloy casting described in the second embodiment, which will not be repeated here.

[0118] It should be noted that the types and models of aluminum-silicon alloy castings can be flexibly adjusted according to production needs and can be widely used in the fields of automobiles, aviation, electronics, etc. For example, aluminum-silicon alloy castings can be, but are not limited to, mechanical arms, partial shells on vehicles (such as engine housings).

[0119] Fourth embodiment

[0120] Please refer to Figure 2 The present application also provides a baking strengthening detection method for alloy castings, which can bake the alloy castings at low temperature to form fine precipitation phases, thereby further improving the strength of the alloy castings. The baking strengthening detection method may include:

[0121] Step 210, baking and strengthening the alloy casting according to a specified baking condition;

[0122] Step 220, obtaining a first performance parameter of the alloy casting before baking, and a second performance parameter of the alloy casting after baking and strengthening;

[0123] Step 230: Based on the first performance parameter and the second performance parameter, according to a preset detection rule, determine the detection result of the alloy casting, wherein the detection result includes an equivalent strengthening value of the alloy casting.

[0124] In step 210 , the alloy casting may be a casting made of alloys of various metal element materials. For example, the alloy casting may be an aluminum-silicon alloy casting made by the method provided in the second embodiment. In this case, step 210 may be a step after step 120 .

[0125] As an example, step 210, performing baking strengthening on the alloy casting according to the specified baking conditions, may include:

[0126] Baking the alloy casting at a first specified temperature and continuously baking for a first specified time;

[0127] After the first designated time period is completed, the alloy casting is baked at a second designated temperature and the baking is continued for the second designated time period, wherein the first designated temperature is 160-190°C and the second designated temperature is 125-155°C.

[0128] In this embodiment, for ease of understanding, the alloy casting is the aforementioned aluminum-silicon alloy casting as an example to illustrate the implementation process of the baking strengthening detection method. Step 210 is: baking the die-cast aluminum-silicon alloy according to the specified baking conditions, and the specified baking conditions are: first baking at a specified high temperature for a period of time, and then baking at a specified low temperature for a period of time, forming a combination of high temperature baking and low temperature baking.

[0129] The first designated temperature (high temperature baking temperature) may include: 160°C, 170°C, 180°C, 190°C.

[0130] The second designated temperature (low temperature baking temperature) may include: 125°C, 135°C, 145°C, 155°C.

[0131] The first specified time or the second specified time (baking time) may include: 10 min, 20 min, 30 min, 40 min, 50 min, 60 min.

[0132] As an optional implementation, the baking condition when the equivalent strengthening value ΔH reaches the maximum is the optimal baking condition, and the optimal baking condition is: the first specified temperature is 170°C, the first specified time is 20 minutes; the second specified temperature is 145°C, and the second specified time is 40 minutes. In this way, it is conducive to obtaining an aluminum-silicon alloy casting with the maximum equivalent strengthening value ΔH.

[0133] In step 220, the first performance parameter may include, but is not limited to, the yield strength σ of the alloy casting. s , tensile strength σ b and elongation δ and work hardening exponent n.

[0134] The second performance parameter may include, but is not limited to, the ultimate yield strength σ of the alloy casting under the kth baking condition: sk , ultimate tensile strength σ bk , Final elongation δ k and the final work hardening index n k .

[0135] Understandably, after the die casting of the aluminum-silicon alloy casting is completed, a tensile specimen can be prepared. The tensile specimen is a test sample for tensile testing. Then, a tensile test is performed on the tensile specimen, and the initial performance parameters are recorded as the first performance parameters. Next, a tensile test is performed on the tensile specimen that has completed the kth baking condition, and the baking performance parameters of the aluminum-silicon alloy casting are recorded as the second performance parameters.

[0136] In this embodiment, after step 220, the method may further include:

[0137] Based on the work hardening constitutive relationship, the first performance parameter and the second performance parameter, a stress-strain curve for describing the tensile stress of the alloy casting is established by fitting, wherein the work hardening constitutive relationship is:

[0138] σ=A+Bε n (1)

[0139] Wherein, σ is the stress of the alloy casting; A is a preset constant term coefficient, which can be obtained through experiments and is related to the initial yield strength; B is the material constant of the alloy casting, ε is the strain of the alloy casting, and n is the work hardening index of the alloy casting before baking. Both B and n can be obtained by fitting experimental data.

[0140] Please refer to Figure 3 , Figure 3 The stress-strain curves before and after baking are shown. The initial performance parameters include yield strength σ s , tensile strength σ band elongation δ and work hardening index n; baking performance parameters include the final yield strength σ corresponding to the kth baking condition sk , ultimate tensile strength σ bk and the final elongation δ k And the final material work hardening index n k .

[0141] The yield strength value is H1 = σ sk -σ s , the tensile strength value is H2 = σ bk -σ b , the plastic weakening value is H3=δ k -δ, H3 is generally a negative value, and the elongation is calculated in dimensionless form. Because die-cast aluminum-silicon alloys often do not have an obvious yield platform, the stress when the residual plastic strain is 0.2% can be used as the yield strength.

[0142] from Figure 3 It can be intuitively observed that after baking strengthening, the changes in strengthening value, weakening value and elongation have occurred, and the mechanical properties of the material have changed significantly.

[0143] Therefore, the mechanical properties of the material will change differently under different baking conditions, and the values ​​of strengthening and weakening will also change differently.

[0144] In step 230, based on the first performance parameter and the second performance parameter, determining the detection result of the alloy casting according to a preset detection rule may include:

[0145] Based on the first performance parameter and the second performance parameter, determining a strengthening value and / or a weakening value of the corresponding parameter;

[0146] Based on the strengthening value and / or weakening value of the corresponding parameter, an equivalent strengthening value is determined to obtain the detection result.

[0147] Wherein, based on the first performance parameter and the second performance parameter, determining the strengthening value and / or weakening value of the corresponding parameter may include:

[0148] Using H1=σ sk -σs, determine the yield strength value H1, where σ sk refers to the final yield strength in the second performance parameter, σs refers to the yield strength in the first performance parameter;

[0149] Using H2=σ bk -σb, determine the tensile strength value H2, where σ bk refers to the ultimate tensile strength in the second performance parameter, and σb refers to the tensile strength in the first performance parameter;

[0150] The plastic weakening value H3 is determined using H3=δk-δ, wherein δk refers to the final elongation in the second performance parameter, and δ refers to the elongation in the first performance parameter.

[0151] In order to accurately consider the effect of baking on the mechanical properties of the material, the following preset calculation rules are used in the embodiment to calculate the equivalent strengthening value ΔH. The larger the ΔH value, the better the baking strengthening effect. For example, based on the strengthening value and / or weakening value of the corresponding parameter, the equivalent strengthening value is determined, including:

[0152] The equivalent strengthening value is determined based on a preset formula, wherein the preset formula is:

[0153]

[0154] H1kσskσs(3)

[0155] H3k=δ-δ(4)

[0156] In the formula, ΔH k is the equivalent strengthening value corresponding to the kth baking condition; H 1k is the yield hardening value corresponding to the kth baking condition, B is the material constant of the alloy casting before baking, and B k is the material constant corresponding to the kth baking condition, H 3k is the plastic weakening value corresponding to the kth baking condition; n refers to the work hardening index of the alloy casting before baking; n k refers to the work hardening index corresponding to the kth baking condition; σs refers to the yield strength of the alloy casting before baking; σ sk refers to the final yield strength corresponding to the kth baking condition; δ refers to the elongation of the alloy casting before baking; δk refers to the final elongation corresponding to the kth baking condition.

[0157] Please refer to Figure 4 , Figure 4 The figure shows a stress-strain curve of an unbaked material and two materials under different baking conditions. Their constitutive relationship functions are:

[0158] σ=143.2+392.9ε0.491

[0159] σ1=161.1+409.6ε0.463

[0160] σ2=194.1+434.9ε0

[0161] The relevant calculation parameters are shown in Table 1 below.

[0162] Table 1:

[0163]

[0164] The baking condition 1 refers to baking at 170°C for 20 minutes and then baking at 145°C for 40 minutes.

[0165] Baking condition 2 means: baking at 190°C for 30 minutes, and then baking at 125°C for 50 minutes.

[0166] Substituting each parameter into the calculation formula of equivalent strengthening value ΔH, we can get:

[0167] ΔH1=70.3

[0168] ΔH2=64.7

[0169] Therefore, it can be explained that baking condition 1 has a better strengthening effect and better comprehensive mechanical properties.

[0170] In order to verify the mechanical properties of the die-cast aluminum silicon alloy that can be low-temperature baked and strengthened prepared by the present invention, the tensile test results of the material under the die-cast aluminum silicon alloy and the high-pressure die-casting process and the baking strengthening process are as shown in Table 2 below.

[0171] Table 2:

[0172]

[0173]

[0174] Therefore, the aluminum-silicon alloy material / casting provided in the embodiment of the present application is a high-strength and high-toughness alloy material that does not require heat treatment, and can meet the performance requirements of die-castings without heat treatment. The aluminum-silicon alloy casting provided by the present invention has excellent mechanical properties under low-temperature baking conditions and can be widely used in the fields of automobiles, aviation, electronics, etc. Utilizing the baking strengthening detection method provided by the present invention, aluminum-silicon alloy castings having a yield strength greater than 160MPa, a tensile strength greater than 300MPa, and an elongation greater than 10% after baking can be obtained.

[0175] In this embodiment, after step 230, the method may further include:

[0176] When the equivalent strengthening value is not within the preset range of qualified characterization, an alarm prompt is issued.

[0177] To achieve the goal of improving strength and reducing part wall thickness, according to the strength requirements of collision simulation and the limitation of elongation after fracture of aluminum-silicon alloy castings by existing connection technology, when:

[0178] ΔH<40, the baking effect is poor;

[0179] 40≤ΔH<60, the baking effect is medium;

[0180] 60≤ΔH<80, the baking effect is good;

[0181] ΔH≥80, excellent baking effect.

[0182] As an example, the preset range can be a value greater than or equal to 60. That is, the equivalent strengthening value ΔH ≥ 60 can meet the product structure design and collision safety requirements. If ΔH < 60, the product structure design is considered unqualified. At this time, the display screen, alarm light, etc. can be controlled to issue an alarm prompt so that engineers can promptly discover that the aluminum-silicon alloy casting is unqualified. In addition, while issuing an alarm prompt, you can return to step 110, or step 120, or step S210 to adjust the parameters in the corresponding steps. For example, the specified parameters involving die casting and the parameters involving baking in step 120 and step S210 are limited by the production line. After referring to previous production experience and benchmarking, the adjustment is small. Therefore, it is possible to return to step 110 to adjust the alloy element content.

[0183] Based on the above design, in the solution provided by the present application, by adjusting the ratio of Al, Si and other appropriate amounts of Mn, Zn, Mg, Cu and other elements, the die-cast aluminum silicon alloy has good strength and plasticity at room temperature; and by baking it at low temperature, a fine precipitate phase can be formed, thereby further improving its strength. In addition, by optimizing the die-casting process parameters, such as temperature and pressure, the die-cast aluminum silicon alloy of the present invention can be rapidly solidified when filling the mold, reducing the generation of pores and shrinkage cavities, improving the density of the casting, and improving the molding quality and mechanical properties of the alloy.

[0184] The traditional way to evaluate the low-temperature baking strengthening performance is to use a simple strengthening value, which cannot take into account the impact of reduced plasticity. The baking strengthening detection method provided by the present invention comprehensively considers the strengthening value, work hardening index and elongation of the material under different strain states, making the baking strengthening detection of alloy castings more scientific, comprehensive and accurate.

[0185] Through the description of the above implementation methods, technical personnel in this field can clearly understand that the present application can be implemented by hardware, and can also be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present application.

[0186] In the embodiments provided in the present application, it should be understood that the disclosed methods and die casting equipment can also be implemented in other ways. The above-described device and method embodiments are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented by a dedicated hardware-based system that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part.

[0187] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An aluminum-silicon alloy material, It is characterized in that Calculated by specified mass percentage, the components of the aluminum-silicon alloy material include: Si: 8.4-9.0%, Mn: 0.6-0.8%, Zn: 0.05-0.35%, Mg: 0.2-0.3%, Cu: 0.1-0.3%, Ti: 0.1-0.18%, V: 0.01-0.03%, Sr: 0.02-0.04%, Fe≤0.1%, Na<0.004%, B<0.002%, La: 0.01-0.02%, Ce: 0.01-0.02%, the balance is Al and unavoidable impurities.

2. An aluminum-silicon alloy casting, It is characterized in that The aluminum-silicon alloy material according to claim 1 is used to obtain an aluminum-silicon alloy casting by die casting.

3. A method for preparing an aluminum-silicon alloy casting, It is characterized in that The method comprises: Prepare alloy raw materials according to the ratio of each element of the aluminum-silicon alloy material according to claim 1; The die-casting equipment is controlled to operate according to specified parameters, and the alloy raw material is die-cast to obtain an aluminum-silicon alloy casting.

4. The method according to claim 3, It is characterized in that The specified parameters include melt temperature, mold temperature, high speed, low speed, high speed position, boost position, boost pressure and vacuum degree of the die-casting equipment; Control die casting equipment to run according to specified parameters, including: Controlling the pouring temperature of the die-casting equipment to be 670-730°C; Controlling the die temperature of the die-casting equipment to be 170-230°C; Control the high speed of the die-casting equipment to be 2.5-3.5 m / s; Control the low speed of the die-casting equipment to 0.15-0.35 m / s; Control the high speed position of the die casting equipment to 240-280 mm; Controlling the boost position of the die-casting equipment to be 260-300 mm; Controlling the casting pressure of the die-casting equipment to be 65-95 MPa; The vacuum degree of the die-casting equipment is controlled to be 20-1000 mbr.

5. The method according to claim 4, It is characterized in that The pouring temperature is 700-710°C; the mold temperature is 230°C; the high speed is 3.0m / s, the low speed is 0.25m / s; the high-speed position is 260mm; the boost position is 280mm; the casting pressure is 80-90MPa; the vacuum degree is 40mbar, and the mold retention time of the die-casting equipment is 10s.

6. A baking strengthening detection method for alloy castings, It is characterized in that The method comprises: The alloy casting is baked and strengthened according to the specified baking conditions, wherein the alloy casting includes an aluminum-silicon alloy casting obtained by the method according to claim 3; Obtaining a first performance parameter of the alloy casting before baking, and a second performance parameter of the alloy casting after baking and strengthening; Based on the first performance parameter and the second performance parameter, a detection result of the alloy casting is determined according to a preset detection rule, and the detection result includes an equivalent strengthening value of the alloy casting.

7. The method according to claim 6, It is characterized in that For alloy castings, baking strengthening is carried out according to the specified baking conditions, including: Baking the alloy casting at a first specified temperature and continuously baking for a first specified time; After the first designated time period is completed, the alloy casting is baked at a second designated temperature and the baking is continued for the second designated time period, wherein the first designated temperature is 160-190°C and the second designated temperature is 125-155°C.

8. The method according to claim 7, It is characterized in that The first designated temperature is 170° C., and the first designated time is 20 minutes; the second designated temperature is 145° C., and the second designated time is 40 minutes.

9. The method according to claim 6, It is characterized in that The first performance parameter includes the yield strength σ of the alloy casting s , tensile strength σ b and elongation δ and work hardening exponent n; The second performance parameter includes the ultimate yield strength σ of the alloy casting under the kth baking condition sk , ultimate tensile strength σ bk , Final elongation δ k and the final work hardening index n k .

10. The method according to claim 9, It is characterized in that Based on the first performance parameter and the second performance parameter, according to a preset detection rule, determining the detection result of the alloy casting includes: Based on the first performance parameter and the second performance parameter, determining a strengthening value and / or a weakening value of the corresponding parameter; Based on the strengthening value and / or weakening value of the corresponding parameter, an equivalent strengthening value is determined to obtain the detection result.

11. The method according to claim 10, It is characterized in that Based on the first performance parameter and the second performance parameter, determining a strengthening value and / or a weakening value of the corresponding parameter comprises: Using H 1 =σ sk -σ b , determine the yield strength value H 1 , where σ sk Refers to the ultimate yield strength in the second performance parameter, σ s Refers to the yield strength among the first performance parameters; Using H 2 =σ bk -σ b , determine the tensile strength value H 2 , where σ bk Refers to the ultimate tensile strength in the second performance parameter, σ b Refers to the tensile strength among the first performance parameters; Using H 3 =δ k -δ, determine the plastic weakening value H 3 , where δ k refers to the final elongation in the second performance parameter, and δ refers to the elongation in the first performance parameter.

12. The method according to claim 10, It is characterized in that Based on the strengthening value and / or weakening value of the corresponding parameter, determining an equivalent strengthening value comprises: The equivalent strengthening value is determined based on a preset formula, wherein the preset formula is: In the formula, ΔH k is the equivalent strengthening value corresponding to the kth baking condition; H 1k is the yield hardening value corresponding to the kth baking condition, B is the material constant of the alloy casting before baking, and B k is the material constant corresponding to the kth baking condition, H 3k is the plastic weakening value corresponding to the kth baking condition; n refers to the work hardening index of the alloy casting before baking; n k refers to the work hardening index corresponding to the kth baking condition; δ refers to the elongation of the alloy casting before baking; δ k Refers to the final elongation corresponding to the kth baking condition.

13. The method according to claim 6, It is characterized in that The method further comprises: Based on the work hardening constitutive relationship, the first performance parameter and the second performance parameter, a stress-strain curve for describing the tensile stress of the alloy casting is established by fitting, wherein the work hardening constitutive relationship is: σ=A+Bε n In the formula, σ is the stress of the alloy casting, A is the preset constant term coefficient, B is the material constant of the alloy casting, ε is the strain of the alloy casting, and n is the work hardening index of the alloy casting before baking.

14. The method according to claim 6, It is characterized in that The method further comprises: When the equivalent strengthening value is not within the preset range of qualified characterization, an alarm is issued, and / or the parameters corresponding to the specified baking conditions are adjusted, and the alloy casting is baked and strengthened according to the specified baking conditions after the parameters are adjusted.

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