CN109957686B - Aluminum-silicon alloy for cylinder sleeve and preparation process - Google Patents

Aluminum-silicon alloy for cylinder sleeve and preparation process Download PDF

Info

Publication number
CN109957686B
CN109957686B CN201910222860.2A CN201910222860A CN109957686B CN 109957686 B CN109957686 B CN 109957686B CN 201910222860 A CN201910222860 A CN 201910222860A CN 109957686 B CN109957686 B CN 109957686B
Authority
CN
China
Prior art keywords
aluminum
alloy
silicon
melt
percent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910222860.2A
Other languages
Chinese (zh)
Other versions
CN109957686A (en
Inventor
陈永禄
洪丽华
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujian University of Technology
Original Assignee
Fujian University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujian University of Technology filed Critical Fujian University of Technology
Priority to CN201910222860.2A priority Critical patent/CN109957686B/en
Publication of CN109957686A publication Critical patent/CN109957686A/en
Application granted granted Critical
Publication of CN109957686B publication Critical patent/CN109957686B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D18/00Pressure casting; Vacuum casting
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C1/00Making alloys
    • C22C1/02Making alloys by melting
    • C22C1/026Alloys based on aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C1/00Making alloys
    • C22C1/02Making alloys by melting
    • C22C1/03Making alloys by melting using master alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C1/00Making alloys
    • C22C1/06Making alloys with the use of special agents for refining or deoxidising
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C21/00Alloys based on aluminium
    • C22C21/02Alloys based on aluminium with silicon as the next major constituent
    • C22C21/04Modified aluminium-silicon alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22FCHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/043Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with silicon as the next major constituent

Abstract

The invention discloses an aluminum-silicon alloy for a cylinder sleeve and a preparation process thereof, wherein the aluminum-silicon alloy comprises the following components in percentage by mass: si: 12-15%, Cu: 1-5%, Ni: 1-4%, Mg: 0.5 to 2.5%, Sr: 0.01-0.1%, mixed rare earth element RE: 0.1-1%, impurity elements: less than 1 percent, and the balance of Al, wherein the sum of the total amount of all the components is 100 percent. The invention takes the aluminum-silicon alloy with the silicon content close to the eutectic point as the matrix, only selectively adds elements such as Cu, Ni, Mg and the like, simplifies the modification process of the alloy phase and weakens the cutting action of the alloy relative to the matrix. Because the silicon content is low, the number of primary crystal silicon phases is small, and a pressure casting forming process (such as extrusion casting, common die casting, low-pressure casting and the like) is adopted, the solid solubility of silicon in alpha-Al is increased, the Sr/RE composite modifier is adopted to modify eutectic silicon and alloy phases, the performance of the aluminum-silicon alloy is comprehensively improved, and the optimized T6 treatment process is combined, so that the product has the advantages of smaller specific gravity, lower linear expansion coefficient, higher wear resistance and volume stability, and the application requirement of the cylinder sleeve is met.

Description

Aluminum-silicon alloy for cylinder sleeve and preparation process
Technical Field
The invention relates to the technical field of metal alloy and preparation thereof, in particular to an aluminum-silicon alloy for a cylinder sleeve and a preparation process thereof.
Background
In order to realize energy conservation and emission reduction of the automobile, green clean energy is developed, and the light weight of the whole automobile is more important. The research shows that: if the weight of the whole automobile is reduced by 10%, the fuel efficiency can be improved by 6% -8%; when the whole vehicle mass of the automobile is reduced by 100 kilograms, the oil consumption per hundred kilometers can be reduced by 0.3-0.6 liter, the weight of the automobile is reduced by 1 percent, and the oil consumption can be reduced by 0.7 percent. In the process of maturing electric automobile technology, it is still the research and development direction of the automobile industry to promote the comprehensive performance of oil gas engine. The cylinder liner is used as an important part in an engine, the working condition is poor, and the quality of the cylinder liner directly influences the performance of the engine. Although the method of embedding the cast iron cylinder sleeve in the aluminum cylinder body is still the mainstream at present, the research and development and application of the aluminum-silicon alloy cylinder sleeve material with high temperature resistance, wear resistance, low expansion coefficient and low density can become the important direction for the future development of the cylinder sleeve industry.
For the research of the silicon-aluminum alloy cylinder sleeve, more experiences are accumulated abroad, and the 'all-aluminum' engine is firstly developed in countries such as Germany, English, American and Japanese, and the like, and the high-silicon aluminum alloy (17-25% Si) cylinder sleeve is used for replacing a cast iron cylinder sleeve and is applied to automobile engines, racing cars and civil engines. The Daimler-Cleisler automobile company has developed a 1.5L "all-aluminum" diesel engine; peak company has realized 50 thousand high-silicon aluminum alloy ingot blanks produced in the month in 2006, and successfully manufactured a high-silicon aluminum alloy cylinder sleeve engine by cooperating with automobile companies in Germany; industrial production of high-silicon aluminum alloy cylinder liners has been started since 2001 by ford corporation, which proposed 30 to 40 ten thousand "all aluminum" cars annually.
The silicon-aluminum alloy cylinder sleeve is late in the field of silicon-aluminum alloy cylinder sleeves in China, and is slow in research and development and few in application. In the preparation process, the method mainly comprises high-silicon aluminum alloy alloying, particle reinforced high-silicon aluminum alloy composite materials and the like, and the key point is to research a primary crystal silicon phase modification technology; in the molding process, centrifugal casting, semi-solid extrusion casting, injection molding and the like are mainly adopted, and the problems of complex process, high equipment cost and the like exist; in addition, in the prior reports, the surface processing technology and the frictional wear performance of the high-silicon aluminum alloy cylinder sleeve are also intensively researched. In some domestic patent applications (for example, CN 104480357A, CN101709414A, CN 102764957A), because the silicon content in the technical scheme is high (13-35% Si, usually more than 16% Si in the application example), the primary crystal silicon phase is in a thick sheet shape, a lath shape or a petal shape, and the matrix is seriously cleaved, the main technical innovation point of the prior research is placed on the modification treatment of the primary crystal silicon phase, or the simple extrusion molding process. In addition, some processes also have the problems of technology lag or environmental protection hidden trouble and the like.
CN 104480357A discloses a high-silicon aluminum alloy cylinder sleeve and a preparation method thereof, wherein a high-silicon aluminum alloy with 17-35% of Si is used as a cylinder sleeve base material, multiple modifiers are used and added in multiple ways, and a metallographic structure picture is used for proving the silicon phase modification effect. However, high-melting-point alloy elements (Ti/Ni/Mn/Fe and the like) with high content are added into the alloy, and no alloy phase exists in a metallographic photograph, so that the effect of the alloy elements is difficult to be really embodied; secondly, the melting point of the alloy matrix is certainly increased after the high-melting-point element is added, however, for the described application examples (17% Si and 25% Si), the casting temperatures (800 ℃ and 830 ℃) adopted by the alloy components are higher than the corresponding melting points of the alloy components by at least 30 ℃ respectively, and the alloy under the process condition is not in a semi-solid state at all, and the so-called semi-solid extrusion casting is not mentioned. Therefore, there are significant errors in this invention from the process technology principle. CN101709414A discloses a high-silicon gradient composite aluminum alloy cylinder sleeve material and a preparation method thereof, wherein a high-silicon aluminum alloy with 13-27% of Si is used as a cylinder sleeve base material, and high-melting-point alloy elements such as Cu/Ni/Mn/Fe/V and Mg elements are added. The optimized implementation technical scheme selects 20.5 percent of Si, and as the silicon content is high, multiple alterants are needed to perform composite alteration treatment on primary crystal silicon, eutectic silicon and other alloy phases which should exist, the process is complex, and a refining agent with high content (70 percent) of hexachloroethane is adopted in the melt purification treatment process, so that the environmental pollution is great. In addition, the technology adopts a centrifugal casting mode, so that oxidation and air entrainment phenomena are easily generated, and the tissue compactness of a cylinder sleeve casting is influenced. But this is a better solution that can be retrieved at present. CN102764957A discloses a manufacturing method of a hypereutectic aluminum-silicon alloy engine cylinder sleeve, wherein a high-silicon aluminum alloy with 13-30% of Si is used as a cylinder sleeve base material, and high-melting-point alloy elements such as Cu/Ni/Mn/Fe and Mg/Zn elements are added. Cr or P and Cr are adopted to modify hypereutectic aluminum alloy materials, hollow aluminum alloy ingots are produced in a continuous casting mode, and then the hollow aluminum alloy ingots are produced through a semi-solid thixoforming process, so that the process is complex, the flow is long, and the cost is high. However, the alloy structure determines the alloy performance, but the three patent applications only describe the improvement of the silicon phase morphology, do not relate to the alloy phase, do not show the alloy phase in the provided metallographic photograph, and are difficult to embody the alloy performance.
In summary, the existing cylinder sleeve material has the following disadvantages: (1) the cylinder liner is mainly made of steel and cast iron, and can basically meet the requirements of light weight of an automobile although the cylinder liner can basically meet the existing working condition on the premise of no new material selection. (2) Most of materials which are published in the current foreign research and can be definitely applied to the cylinder liner are high-silicon aluminum alloy, namely 17-25% of Si. Some domestic patent applications expand the range of the components when describing the components, namely 13-35% of Si, and place the main technical innovation point on the modification treatment of the primary crystal silicon phase, although various elements are added, the key effect of other alloy elements other than aluminum-silicon-based components is directly ignored, and the important effect of the types and different forms of the alloy phases of non-silicon phases on the improvement of the material performance is also ignored.
Disclosure of Invention
The invention aims to provide an aluminum-silicon alloy for a cylinder sleeve and a preparation process thereof, aiming at the defects of the existing cylinder sleeve material. On one hand, aluminum replaces steel, and the requirements of light weight, small thermal expansion coefficient, higher thermal conductivity, excellent casting performance, wear resistance and the like of the aluminum-silicon alloy cylinder liner material are met. On the other hand, the content of silicon in the matrix is reduced, the solid solubility of silicon element in the matrix is improved by combining a pressure casting forming process, the form of a silicon phase is directly and effectively changed, and the complex operation of multiple deterioration of the silicon phase in the smelting process is simplified; proper alloy elements are added to control the formation of an alloy phase with excellent form, and the comprehensive performance of the alloy material is improved.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the aluminum-silicon alloy for the cylinder sleeve comprises the following components in percentage by mass: si: 12-15%, Cu: 1-5%, Ni: 1-4%, Mg: 0.5 to 2.5%, Sr: 0.01-0.1%, mixed rare earth element RE: 0.1-1%, impurity elements: less than 1 percent, and the balance of Al, wherein the sum of the total amount of all the components is 100 percent.
The impurity elements refer to P, S, Fe and other elements which are inevitably determined by the raw material grade and the casting process and are harmful to the structure and the performance of the final alloy.
The preparation process of the aluminum-silicon alloy for the cylinder sleeve comprises the following steps:
1) the aluminum-silicon alloy comprises the following raw materials by weight: industrial pure aluminum (the purity is more than or equal to 99.0 percent), industrial pure silicon (the purity is more than or equal to 98.0 percent), Al-50Cu, Al-10Ni, industrial pure magnesium (the purity is more than or equal to 99.8 percent), Al-10Sr and Al-10RE, wherein RE in the Al-10RE is mixed rare earth, and the percentage of (La + Ce) in the mixed rare earth is more than or equal to 99.6 percent; in order to ensure that the silicon is fully melted into the aluminum, the industrial pure silicon needs to be crushed into blocks, and the weight of the melted alloy needs to be considered comprehensively in specific size, so that the addition is facilitated; drying the ingot or block raw materials at 150-200 ℃ for 1h, wherein in order to prevent the effective components from volatilizing and losing efficacy, the powdered flux is not recommended to be dried and should be dried and stored;
2) setting the temperature of a smelting furnace to be 750-760 ℃, preheating to 200-220 ℃, adding industrial pure aluminum accounting for 30-35% of the total amount of the required industrial pure aluminum, and heating to be molten;
3) after the industrial pure aluminum is completely melted, adding an intermediate alloy Al-50Cu and Al-10Ni into the aluminum liquid, after the intermediate alloy is completely melted, adding industrial pure silicon and pressing the pure silicon by the residual industrial pure aluminum to ensure that the pure silicon is completely submerged into a melt, avoiding floating, uniformly spreading an impurity removal flux on the surface of the aluminum liquid, and adjusting the furnace temperature to 780-785 ℃;
4) after the industrial pure silicon is completely melted, crushing massive scum on the surface of the melt by using a slag removing tool, so as to be beneficial to slag-aluminum separation, pressing industrial pure magnesium into molten aluminum by using a bell jar after the slag is completely removed, preventing burning loss, standing the molten aluminum for 10-15 min, ensuring that alloy elements are uniformly diffused, and then uniformly spreading an impurity removing flux on the surface of the molten aluminum;
5) controlling the temperature of an aluminum alloy melt to be 735-745 ℃, performing degassing refining on the melt by using an inert gas rotary blowing device, inserting a non-blocking rotary nozzle from the central axis of the crucible melt, placing the end part of the nozzle below the liquid level of the melt at 2/3, then introducing dried inert gas into the melt through a pipeline, starting the nozzle to rotate a switch, enabling the inert gas to be dispersed in the aluminum alloy melt in the form of fine bubbles, continuing the degassing process for 10-15 min, then standing for 10-15 min, and uniformly spreading an impurity removal flux on the surface of the melt;
6) controlling the temperature of the aluminum alloy melt to be 715-725 ℃, adding Al-10Sr and Al-10RE for modification treatment, and after the aluminum alloy melt is completely melted, horizontally stirring the melt to ensure that alloy elements are uniformly diffused;
7) heating to 780-785 ℃, preserving heat for 10-15 min, repeating the slag skimming operation, scooping a certain amount of aluminum alloy melt by using a liquid scooping spoon, stably pouring the aluminum alloy melt into a charging barrel of pressure casting equipment, and forming products according to the pressure casting process requirements of cylinder liner products with different specifications to obtain cylinder liner castings;
8) the liner casting was subjected to a T6 treatment.
Further, the quantitative batching is calculated according to the target components of the aluminum-silicon alloy and the element burning loss rate, and the element burning loss rate is as follows: si: 2%, Cu: 0.5%, Ni: 0.5%, Mg: 5 percent.
The impurity removal flux is NaCl, KCl, NaF and Na3AlF6And mixtures of two or more of the salt compounds.
The total addition amount of the impurity removal solvent is 0.1-0.5% of the total amount of the melt, and in the step 3), the step 4) and the step 5), the addition amount ratio of the impurity removal solvent is 2:1: 1.
The inert gas is N2 or Ar, and the purity of the inert gas is more than 99.9%.
The specific process for treating T6 comprises the following steps: the solid solution temperature is 540-550 ℃, the solid solution time is 4-4.5 h, and water quenching is carried out in time after discharging, wherein the water quenching temperature is 50-80 ℃; the aging temperature is 230-240 ℃, the aging time is 4-4.5 h, and the product is discharged from the furnace and cooled to room temperature by air.
In the preparation process of the invention, all smelting tools and moulds which are in direct contact with the molten aluminum are treated as follows: drying for 1-2 h at 250-300 ℃, then uniformly brushing zinc oxide coating on the surface, and drying for 0.5-1 h at 200 ℃.
By adopting the technical scheme, the aluminum-silicon alloy with the silicon content close to the eutectic point is taken as the matrix, only Cu, Ni, Mg and other elements are selectively added, and Fe and Mn elements which are easy to generate coarse or long needle-shaped phases are not increased, so that the modification process of the alloy phase is simplified, and the cracking effect of the alloy relative to the matrix is weakened. Because the silicon content is low, the number of primary crystal silicon phases is small and small, and in addition, the solid solubility of silicon in alpha-Al is increased by adopting a pressure casting forming process (squeeze casting, common die casting, low-pressure casting and the like), the primary crystal silicon phases which are fine, high in roundness and uniform in distribution can be obtained without adding a primary crystal silicon phase modifier, and the cost is saved; the Sr/RE composite alterant is adopted to modify eutectic silicon and alloy phases, the performance of the aluminum-silicon alloy is comprehensively improved, and the optimized T6 treatment process is combined, so that the product has the advantages of smaller specific gravity, lower linear expansion coefficient, higher wear resistance and volume stability, and the application requirement of the cylinder liner is met.
The invention has the following advantages;
(1) the alloy comprises the following main components: the silicon content of the aluminum-silicon alloy matrix is reduced, and the generation of coarse primary crystal silicon phases is avoided; fe and Mn which are easy to generate needle-shaped, coarse sheet-shaped or skeleton-shaped phases are not added and effectively controlled; the addition variety of alloy elements is reduced, and eutectic-like group structures with multiphase composition, fine and round shapes are formed at the original aluminum-silicon alloy eutectic group and with the eutectic silicon, so that the comprehensive performance of the alloy is improved under the hypereutectic condition.
(2) The comprehensive modification treatment process of the hypereutectic aluminum-silicon alloy comprises the following steps: the modification treatment of eutectic silicon and primary crystal silicon by adopting multiple or special modifiers aiming at the high-silicon alloy is avoided, and the influence of the additive elements of the modifiers on the additive amount of effective alloy elements of the target alloy can be avoided. As disclosed in the patent, for the primary silicon phase, a mixture of a modification refiner Al-Ti-C-RE and a copper-phosphorus alloy or a sulfur-containing alloy or an intermediate alloy of Al-Ti-C-RE-P is adopted, so that the modification process is simplified.
(3) The process fully utilizes the refining effect of pressure casting molding on the silicon phase of the aluminum-silicon alloy and improves the solid solution effect of silicon elements in alpha-Al, can directly and effectively change the form of the silicon phase, and simplifies the complex operation of multiple deterioration of the silicon phase in the smelting process.
(4) The adding sequence of the alloy elements, particularly the adding mode of the silicon element, is beneficial to fully dissolving the alloy elements with high melting point and low density into the aluminum melt and uniformly diffusing the alloy elements, and effectively reducing the content of miscellaneous gas.
(5) The physical refining is carried out by adopting inert gas, and no refining agent polluting the environment is added.
(6) The pressure forming (such as extrusion casting, common die casting, low-pressure casting and the like) is adopted, the tissue compactness is improved, and the oxidation and air entrainment phenomena which are easily generated in a centrifugal casting mode can be avoided.
Drawings
FIG. 1 is a metallographic structure (OM) of an aluminum-silicon alloy cylinder liner obtained by the process of the present invention in a state of pressure casting and T6 treatment, wherein (a) is an alloy macroscopic structure morphology, and (b) is an alloy macroscopic structure morphology;
FIG. 2 is a phase analysis (SEM + EDS) of an Al-Si alloy eutectic compact structure treated with squeeze casting + T6.
Detailed Description
Example 1
The aluminum-silicon alloy for the cylinder sleeve comprises the following components in percentage by mass: si: 12%, Cu: 3%, Ni: 4%, Mg: 0.5%, Sr: 0.05%, mixed rare earth element RE: 1%, impurity elements: less than 1 percent, and the balance of Al, wherein the sum of the total amount of all the components is 100 percent.
The preparation process of the aluminum-silicon alloy for the cylinder sleeve comprises the following steps:
1) the aluminum-silicon alloy target components are quantitatively proportioned by adopting the following raw materials: industrial pure aluminum (the purity is more than or equal to 99.0 percent), industrial pure silicon (the purity is more than or equal to 98.0 percent), Al-50Cu, Al-10Ni, industrial pure magnesium (the purity is more than or equal to 99.8 percent), Al-10Sr and Al-10RE, wherein RE in the Al-10RE is mixed rare earth, and the percentage of (La + Ce) in the mixed rare earth is more than or equal to 99.6 percent;
the quantitative batching is calculated according to the target components of the aluminum-silicon alloy and the element burning loss rate, wherein the element burning loss rate is as follows: si: 2%, Cu: 0.5%, Ni: 0.5%, Mg: 5 percent;
preparing flux (composed of NaCl, KCl, NaF, Na)3AlF6Composition), the total addition amount is 0.1 percent of the total amount of the fusant;
2) preheating raw materials and tools: in order to ensure that the silicon is fully melted into the aluminum, the industrial pure silicon needs to be crushed into blocks, and the weight of the melted alloy needs to be considered comprehensively in specific size, so that the addition is facilitated; the ingot casting or block raw materials need to be dried for 1h at 150 ℃, and in order to prevent the effective components from volatilizing and losing efficacy, the powdered flux is not recommended to be dried and should be dried and stored; in the preparation process, all smelting tools and moulds which are in direct contact with the aluminum liquid are dried for 2 hours at 250 ℃, then zinc oxide coating is uniformly coated on the surface of the moulds, and the moulds are dried for 0.5 hour at 200 ℃;
3) setting the temperature of a smelting furnace to 750 ℃, preheating to 200 ℃, adding industrial pure aluminum accounting for 30 percent of the total amount of the required industrial pure aluminum, and heating to be molten;
4) after the industrial pure aluminum is completely melted, adding an intermediate alloy Al-50Cu and Al-10Ni into the aluminum liquid, after the intermediate alloy is completely melted, adding industrial pure silicon and pressing the pure silicon by the residual industrial pure aluminum to ensure that the pure silicon is completely submerged into the melt, avoiding floating, uniformly spreading an impurity removal flux on the surface of the aluminum liquid, wherein the addition amount is 50% of the total amount of the impurity removal flux, and adjusting the furnace temperature to 780 ℃;
5) after the industrial pure silicon is completely melted, crushing massive scum on the surface of the melt by using a slag removing tool, which is beneficial to separating slag from aluminum, pressing industrial pure magnesium into aluminum liquid by using a bell jar after the slag is completely removed, preventing burning loss, standing the aluminum liquid for 10min, ensuring that alloy elements are uniformly diffused, and then uniformly spreading an impurity removal flux on the surface of the aluminum liquid, wherein the addition amount is 25% of the total amount of the impurity removal flux;
6) controlling the temperature of the aluminum alloy melt to 735 ℃, and using inert gas (N)2And the purity is more than 99.9 percent), inserting a non-blocking rotary spray head from the central axis of the crucible melt, placing the end part of the spray head at 2/3 below the melt liquid level, then introducing dried inert gas into the melt through a pipeline, starting a rotary switch of the spray head to disperse the inert gas in the aluminum alloy melt in a fine bubble mode, continuing the degassing process for 10min, then standing for 10min, and uniformly scattering the residual impurity removal flux on the surface of the melt;
7) controlling the temperature of the aluminum alloy melt to be 715 ℃, adding Al-10Sr and Al-10RE for modification treatment, and horizontally stirring the melt after the melt is completely melted to ensure that alloy elements are uniformly diffused;
8) heating to 780 ℃ and preserving heat for 15min, repeating the slag removing operation, scooping a certain amount of aluminum alloy melt by using a liquid scooping spoon, stably pouring the aluminum alloy melt into a charging barrel of pressure casting equipment, and forming a product according to the pressure casting process requirements of cylinder liner products with different specifications to obtain a cylinder liner casting;
9) and (3) carrying out T6 treatment on the cylinder sleeve casting: the solid solution temperature is 540 ℃, the solid solution time is 4.5h, and water quenching is carried out in time after discharging, wherein the water quenching temperature is 50 ℃; the aging temperature is 230 ℃, the aging time is 4.5h, and the product is discharged from the furnace and cooled to room temperature.
Example 2
The aluminum-silicon alloy for the cylinder sleeve comprises the following components in percentage by mass: si: 13.5%, Cu: 5%, Ni: 1%, Mg: 1.5%, Sr: 0.1%, mixed rare earth element RE: 0.1%, impurity elements: less than 1 percent, and the balance of Al, wherein the sum of the total amount of all the components is 100 percent.
The preparation process of the aluminum-silicon alloy for the cylinder sleeve comprises the following steps:
1) the aluminum-silicon alloy target components are quantitatively proportioned by adopting the following raw materials: industrial pure aluminum (the purity is more than or equal to 99.0 percent), industrial pure silicon (the purity is more than or equal to 98.0 percent), Al-50Cu, Al-10Ni, industrial pure magnesium (the purity is more than or equal to 99.8 percent), Al-10Sr and Al-10RE, wherein RE in the Al-10RE is mixed rare earth, and the percentage of (La + Ce) in the mixed rare earth is more than or equal to 99.6 percent;
the quantitative batching is calculated according to the target components of the aluminum-silicon alloy and the element burning loss rate, wherein the element burning loss rate is as follows: si: 2%, Cu: 0.5%, Ni: 0.5%, Mg: 5 percent;
removing flux (prepared from NaCl, KCl, NaF, Na)3AlF6Composition), the total addition amount is 0.25 percent of the total amount of the fusant;
2) preheating raw materials and tools: in order to ensure that the silicon is fully melted into the aluminum, the industrial pure silicon needs to be crushed into blocks, and the weight of the melted alloy needs to be considered comprehensively in specific size, so that the addition is facilitated; the ingot casting or block raw materials need to be dried for 1h at 200 ℃, and in order to prevent the effective components from volatilizing and losing efficacy, the powdered flux is not recommended to be dried and should be dried and stored; in the preparation process, all smelting tools and moulds which are in direct contact with the aluminum liquid are dried for 1h at 300 ℃, then zinc oxide coating is uniformly coated on the surface of the moulds, and the moulds are dried for 1h at 200 ℃;
3) setting the temperature of a smelting furnace to be 760 ℃, preheating to 220 ℃, adding industrial pure aluminum accounting for 35 percent of the total amount of the required industrial pure aluminum, and heating to be molten;
4) after the industrial pure aluminum is completely melted, adding an intermediate alloy Al-50Cu and Al-10Ni into the aluminum liquid, after the intermediate alloy is completely melted, adding industrial pure silicon and pressing the pure silicon by the residual industrial pure aluminum to ensure that the pure silicon is completely submerged into the melt, avoiding floating, uniformly spreading an impurity removal flux on the surface of the aluminum liquid, wherein the addition amount is 50 percent of the total amount of the impurity removal flux, and adjusting the furnace temperature to 785 ℃;
5) after the industrial pure silicon is completely melted, crushing massive scum on the surface of the melt by using a slag removing tool, which is beneficial to separating slag from aluminum, pressing industrial pure magnesium into molten aluminum by using a bell jar after the slag is completely removed, preventing burning loss, standing the molten aluminum for 5min, ensuring that alloy elements are uniformly diffused, and then uniformly spreading an impurity removal flux on the surface of the molten aluminum, wherein the addition amount is 25% of the total amount of the impurity removal flux;
6) controlling the temperature of an aluminum alloy melt to be 745 ℃, performing degassing refining on the melt by using an inert gas (Ar, the purity is more than 99.9%) rotary blowing device, firstly inserting a non-blocking rotary nozzle from the central axis of the crucible melt, placing the nozzle end part below the melt liquid level to 2/3, then introducing the dried inert gas into the melt through a pipeline, starting the nozzle rotary switch to ensure that the inert gas is dispersed and distributed in the aluminum alloy melt in fine bubbles, continuing the degassing process for 15min, then standing for 15min, and uniformly scattering the residual impurity-removing flux on the surface of the melt;
7) controlling the temperature of the aluminum alloy melt to be 725 ℃, adding Al-10Sr and Al-10RE for modification treatment, and horizontally stirring the melt after the melt is completely melted to ensure that alloy elements are uniformly diffused;
8) heating to 785 ℃, preserving heat for 10min, repeating the slag skimming operation, scooping a certain amount of aluminum alloy melt by using a liquid scooping spoon, stably pouring the aluminum alloy melt into a charging barrel of pressure casting equipment, and forming a product according to the pressure casting process requirements of cylinder liner products with different specifications to obtain a cylinder liner casting;
9) and (3) carrying out T6 treatment on the cylinder sleeve casting: the solid solution temperature is 550 ℃, the solid solution time is 4h, and water quenching is carried out in time after discharging, wherein the water quenching temperature is 80 ℃; the aging temperature is 240 ℃, the aging time is 4 hours, and the product is discharged from the furnace and cooled to room temperature.
Example 3
The aluminum-silicon alloy for the cylinder sleeve comprises the following components in percentage by mass: si: 15%, Cu: 1%, Ni: 2.5%, Mg: 2.5%, Sr: 0.01%, mixed rare earth element RE: 0.5%, impurity elements: less than 1 percent, and the balance of Al, wherein the sum of the total amount of all the components is 100 percent.
The preparation process of the aluminum-silicon alloy for the cylinder sleeve comprises the following steps:
1) the aluminum-silicon alloy target components are quantitatively proportioned by adopting the following raw materials: industrial pure aluminum (the purity is more than or equal to 99.0 percent), industrial pure silicon (the purity is more than or equal to 98.0 percent), Al-50Cu, Al-10Ni, industrial pure magnesium (the purity is more than or equal to 99.8 percent), Al-10Sr and Al-10RE, wherein RE in the Al-10RE is mixed rare earth, and the percentage of (La + Ce) in the mixed rare earth is more than or equal to 99.6 percent;
the quantitative batching is calculated according to the target components of the aluminum-silicon alloy and the element burning loss rate, wherein the element burning loss rate is as follows: si: 2%, Cu: 0.5%, Ni: 0.5%, Mg: 5 percent;
removing flux (prepared from NaCl, KCl, NaF, Na)3AlF6Composition), the total addition amount is 0.5 percent of the total amount of the fusant;
2) preheating raw materials and tools: in order to ensure that the silicon is fully melted into the aluminum, the industrial pure silicon needs to be crushed into blocks, and the weight of the melted alloy needs to be considered comprehensively in specific size, so that the addition is facilitated; the ingot casting or block raw materials need to be dried for 1h at 180 ℃, and in order to prevent the effective components from volatilizing and losing efficacy, the powdered flux is not recommended to be dried and should be dried and stored; in the preparation process, all smelting tools and moulds which are in direct contact with the aluminum liquid are dried for 1.5h at 280 ℃, then zinc oxide coating is uniformly coated on the surface of the moulds, and the moulds are dried for 0.5h at 200 ℃;
3) setting the temperature of a smelting furnace to 760 ℃, preheating to 200 ℃, adding industrial pure aluminum accounting for 30 percent of the total amount of the required industrial pure aluminum, and heating to be molten;
4) after the industrial pure aluminum is completely melted, adding an intermediate alloy Al-50Cu and Al-10Ni into the aluminum liquid, after the intermediate alloy is completely melted, adding industrial pure silicon and pressing the pure silicon by the residual industrial pure aluminum to ensure that the pure silicon is completely submerged into the melt, avoiding floating, uniformly spreading an impurity removal flux on the surface of the aluminum liquid, wherein the addition amount is 50% of the total amount of the impurity removal flux, and adjusting the furnace temperature to 780-785 ℃;
5) after the industrial pure silicon is completely melted, crushing massive scum on the surface of the melt by using a slag removing tool, which is beneficial to separating slag from aluminum, pressing industrial pure magnesium into aluminum liquid by using a bell jar after the slag is completely removed, preventing burning loss, standing the aluminum liquid for 10min, ensuring that alloy elements are uniformly diffused, and then uniformly spreading an impurity removal flux on the surface of the aluminum liquid, wherein the addition amount is 20% of the total amount of the impurity removal flux;
6) controlling the temperature of the aluminum alloy melt to 740 ℃, and using inert gas (N)2And the purity is more than 99.9 percent), inserting a non-blocking rotary spray head from the central axis of the crucible melt, placing the end part of the spray head at 2/3 below the melt liquid level, then introducing dried inert gas into the melt through a pipeline, starting a rotary switch of the spray head to disperse the inert gas in the aluminum alloy melt in a fine bubble mode, continuing the degassing process for 10min, then standing for 10min, and uniformly scattering the residual impurity removal flux on the surface of the melt;
7) controlling the temperature of the aluminum alloy melt to be 720 ℃, adding Al-10Sr and Al-10RE for modification treatment, and horizontally stirring the melt after the melt is completely melted to ensure that alloy elements are uniformly diffused;
8) heating to 780 ℃ and preserving heat for 10min, repeating the slag skimming operation, scooping a certain amount of aluminum alloy melt by using a liquid scooping spoon, stably pouring the aluminum alloy melt into a charging barrel of pressure casting equipment, and forming a product according to the pressure casting process requirements of cylinder liner products with different specifications to obtain a cylinder liner casting;
9) and (3) carrying out T6 treatment on the cylinder sleeve casting: the solid solution temperature is 540 ℃, the solid solution time is 4h, and water quenching is carried out in time after discharging, wherein the water quenching temperature is 65 ℃; the aging temperature is 230 ℃, the aging time is 4 hours, and the product is discharged from the furnace and cooled to room temperature.
Fig. 1 shows the metallographic structure of the aluminum-silicon alloy cylinder liner in the as-pressure cast + T6 state obtained in example 3. Visible under a metallographic microscope (OM): fine granular silicon phase (mainly eutectic silicon) and a plurality of alloy phases are dispersed on the Al matrix to play a full dispersion strengthening effect; coarse primary crystal silicon under the condition of the same silicon content is not seen in the structure (compared with the balance structure corresponding to the silicon content in the Al-Si binary alloy equilibrium phase diagram), which shows that under the condition of the technical scheme of the invention, more silicon elements are dissolved in the matrix in a solid manner due to the double effects of the forming pressure and the heat treatment, so that a better solid solution strengthening effect can be achieved. The area ratio of the solid-solution alpha-Al to the eutectic-like clusters composed of the precipitated phases is 1.27 to 1.41, and the dual strengthening effect is further exhibited.
For different contrast precipitation in tissueThe phases were observed by Scanning Electron Microscopy (SEM) and energy spectral analysis (EDS), see FIG. 2. By combining the element structure and the phase possibly existing in the alloy, the following can be judged: the gray spherical particle phase is a silicon phase, under the treatment process condition, eutectic silicon is subjected to fusing separation and spheroidization and is dispersedly distributed on the substrate in a spherical particle shape, and the dispersed silicon phase can play a role in pinning dislocation in the deformation process, so that the mechanical property of the alloy is improved; the larger white flaky phase is Al3Ni, and the white spherical phase is Al3CuNi, the existence of the nickel-rich phases can improve the volume and dimensional stability of the alloy and improve the high-temperature strength and heat resistance; the individual white needle-shaped phase consists of a nickel-rich phase and an iron-rich phase AlSiFe, and is in a short and thin needle shape, so that the matrix is not cracked; the light gray block phase is an AlSiMgCu multi-element composite phase.
The results of the performance test of the alloy (T6 state) and a cylinder liner of a certain foreign brand under the same conditions are compared with the performance of a cylinder liner product material of a better technical scheme (CN101709414A) in a published patent application, and the results are shown in a table 1.
TABLE 1 comparison of the Material Properties of aluminum-silicon alloy Cylinder liner products
Experimental conditions were inconsistent and could not be directly compared.
Comparing the data in table 1, it can be seen that: the comprehensive performance of the cylinder liner product material produced by the invention is superior to that of foreign similar products; due to the difference of alloy components (especially aluminum-silicon alloy matrix), the hardness level of the cylinder liner product produced by the invention is slightly lower than the index disclosed in the patent CN101709414A, but the strength level is equivalent, the linear thermal expansion coefficient is obviously superior, and the application requirement can be met.

Claims (9)

1. A preparation process of aluminum-silicon alloy for cylinder sleeves is characterized by comprising the following steps: the aluminum-silicon alloy comprises the following components in percentage by mass: si: 12-15%, Cu: 1-5%, Ni: 1-4%, Mg: 0.5 to 2.5%, Sr: 0.01-0.1%, mixed rare earth element RE: 0.1-1%, impurity elements: less than 1 percent, the balance being Al, and the sum of the total amount of all the components being 100 percent;
the preparation process of the aluminum-silicon alloy comprises the following steps:
1) the aluminum-silicon alloy comprises the following raw materials by weight: the alloy is prepared from industrial pure aluminum, industrial pure silicon, industrial pure magnesium, Al-50Cu, Al-10Ni, Al-10Sr and Al-10RE, wherein in the Al-10RE, RE is mixed rare earth, and the percentage of (La + Ce) in the mixed rare earth is more than or equal to 99.6 percent;
2) setting the temperature of a smelting furnace to be 750-760 ℃, preheating to 200-220 ℃, adding industrial pure aluminum accounting for 30-35% of the total amount of the required industrial pure aluminum, and heating to be molten;
3) after the industrial pure aluminum is completely melted, adding an intermediate alloy Al-50Cu and Al-10Ni into the aluminum liquid, after the intermediate alloy is completely melted, adding industrial pure silicon and pressing the pure silicon by the residual industrial pure aluminum to ensure that the pure silicon is completely immersed into the melt, uniformly spreading an impurity removal flux on the surface of the aluminum liquid, and adjusting the furnace temperature to 780-785 ℃;
4) after the industrial pure silicon is completely melted, crushing massive scum on the surface of the melt by using a slag removing tool, pressing industrial pure magnesium into aluminum liquid by using a bell jar, standing the aluminum liquid for 10-15 min, and then uniformly scattering impurity removing flux on the surface of the aluminum liquid;
5) controlling the temperature of the aluminum alloy melt to be 735-745 ℃, performing melt degassing refining by using an inert gas rotary blowing device, inserting a rotary spray head from the central axis of the crucible melt, then feeding the dried inert gas into the melt through a pipeline, starting a spray head rotary switch to disperse the inert gas in the aluminum alloy melt in the form of bubbles, continuing the degassing process for 10-15 min, then standing for 10-15 min, and uniformly spreading an impurity removal flux on the surface of the melt;
6) controlling the temperature of the aluminum alloy melt to be 715-725 ℃, adding Al-10Sr and Al-10RE for modification treatment, and horizontally stirring the melt after the melt is completely melted;
7) heating to 780-785 ℃, preserving heat for 10-15 min, repeating slag skimming operation, pouring a certain amount of aluminum alloy melt into a charging barrel of pressure casting equipment, and molding products according to the pressure casting process requirements of cylinder liner products with different specifications to obtain cylinder liner castings;
8) the liner casting was subjected to a T6 treatment.
2. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the quantitative batching is calculated according to the target components of the aluminum-silicon alloy and the element burning loss rate, and the element burning loss rate is as follows: si: 2%, Cu: 0.5%, Ni: 0.5%, Mg: 5 percent.
3. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the impurity removal flux consists of salt compounds, wherein the salt compounds are NaCl, KCl, NaF and Na3AlF6A mixture of two or more of (1).
4. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the total addition amount of the impurity removal flux is 0.1-0.5% of the total amount of the melt.
5. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 4, wherein the process comprises the following steps: in the steps 3), 4) and 5), the addition ratio of the impurity removal flux is 2:1: 1.
6. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the inert gas is N2Or Ar, the purity of the inert gas is more than 99.9 percent.
7. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the specific process for treating T6 comprises the following steps: the solid solution temperature is 540-550 ℃, the solid solution time is 4-4.5 h, and water quenching is carried out in time after discharging, wherein the water quenching temperature is 50-80 ℃; the aging temperature is 230-240 ℃, the aging time is 4-4.5 h, and the product is discharged from the furnace and cooled to room temperature by air.
8. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: all smelting tools and moulds in direct contact with the molten aluminum are treated as follows: drying for 1-2 h at 250-300 ℃, then uniformly brushing zinc oxide coating on the surface of the zinc oxide coating, and drying for 0.5-1 h at 180-200 ℃.
9. The process for preparing the aluminum-silicon alloy for the cylinder sleeve according to claim 1, which is characterized in that: the purity of the industrial pure aluminum is more than or equal to 99.0 percent, the purity of the industrial pure silicon is more than or equal to 98.0 percent, and the purity of the industrial pure magnesium is more than or equal to 99.8 percent.
CN201910222860.2A 2019-03-22 2019-03-22 Aluminum-silicon alloy for cylinder sleeve and preparation process Active CN109957686B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910222860.2A CN109957686B (en) 2019-03-22 2019-03-22 Aluminum-silicon alloy for cylinder sleeve and preparation process

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910222860.2A CN109957686B (en) 2019-03-22 2019-03-22 Aluminum-silicon alloy for cylinder sleeve and preparation process

Publications (2)

Publication Number Publication Date
CN109957686A CN109957686A (en) 2019-07-02
CN109957686B true CN109957686B (en) 2020-08-18

Family

ID=67024683

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910222860.2A Active CN109957686B (en) 2019-03-22 2019-03-22 Aluminum-silicon alloy for cylinder sleeve and preparation process

Country Status (1)

Country Link
CN (1) CN109957686B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110453117B (en) * 2019-07-26 2021-02-12 柳州职业技术学院 High-performance A356 aluminum alloy refining and strengthening and toughening heat treatment process
CN110387478B (en) * 2019-08-06 2020-09-08 银邦金属复合材料股份有限公司 Semi-continuous casting method of aluminum-silicon alloy cast ingot

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9517045D0 (en) * 1995-08-19 1995-10-25 Gkn Sankey Ltd Method of manufacturing a cylinder block
US6918970B2 (en) * 2002-04-10 2005-07-19 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration High strength aluminum alloy for high temperature applications
US6921512B2 (en) * 2003-06-24 2005-07-26 General Motors Corporation Aluminum alloy for engine blocks
CN1775979A (en) * 2005-12-02 2006-05-24 昆明贵金属研究所 Nouel high-strength wear-resisting and corrosion-resisting aluminium alloy
JP5157684B2 (en) * 2008-06-30 2013-03-06 日本軽金属株式会社 Hypereutectic Al-Si alloy casting method and ingot
CN101709414B (en) * 2009-11-10 2011-09-28 中国兵器工业第五二研究所 High silicon gradient composite aluminum alloy cylinder sleeve material and preparation method thereof
CN103160715B (en) * 2011-12-19 2016-08-03 中国兵器科学研究院宁波分院 A kind of Gradient Aluminium Alloy cylinder jacket material and preparation method thereof
US9834828B2 (en) * 2014-04-30 2017-12-05 GM Global Technology Operations LLC Cast aluminum alloy components
CN104846240B (en) * 2015-04-17 2017-11-21 中原内配集团安徽有限责任公司 A kind of transcocrystallized Al-Si alloy cylinder sleeve and preparation method thereof
CN105603266B (en) * 2015-12-22 2017-07-18 山东汇川汽车部件有限公司 It is a kind of for aluminum alloy cylinder sleeve of automobile engine and preparation method thereof
CN108690925A (en) * 2018-06-13 2018-10-23 中原内配集团安徽有限责任公司 A kind of aluminium silicon titanium alloy cylinder jacket and its processing technology

Also Published As

Publication number Publication date
CN109957686A (en) 2019-07-02

Similar Documents

Publication Publication Date Title
CN101503773B (en) Heat resisting low expansion silumin and preparation thereof
CN109957686B (en) Aluminum-silicon alloy for cylinder sleeve and preparation process
CN100338250C (en) High strength and high toughness cast magnesium alloy and preparing process thereof
Gauthier et al. Heat treatment of 319.2 aluminium automotive alloy Part 1, Solution heat treatment
CN100467644C (en) Composite aluminium alloy for piston and producing process
CN102851575B (en) Oxidation-resistant alloying grey cast iron and preparation method thereof
Tenekedjiev et al. Hypereutectic aluminium-silicon casting alloys—a review
CN102965551A (en) Hypereutectic aluminium-silicon alloy and preparation method thereof
CN104561688A (en) Heat-resistant cast aluminum alloy and gravity casting method thereof
CN100406159C (en) Method for casting Mg-Al-Zn based magnesium alloy with high strength and high tenacity
CN101220431A (en) Aluminum alloy for engine components
CN101215658A (en) High-silicon aluminum alloy and preparation method thereof
Kearney et al. Aluminum foundry products
CN108300884B (en) A kind of hypoeutectic Al-Mg2The rotten and thinning method of Si alloy
CN101775529A (en) High-strength cast aluminum-silicon alloy for engine body and preparation method thereof
CN101538667B (en) High-strength and wear-resistant cocrystallized Al-Si alloy forging stock material and preparation method thereof
CN110029255B (en) High-strength, high-toughness and high-modulus sand-type gravity casting magnesium alloy and preparation method thereof
CN110643862A (en) Aluminum alloy for new energy automobile battery shell and pressure casting preparation method thereof
CN111155007A (en) Preparation method of high-strength 2000 series aluminum alloy based on selective laser melting forming technology
CN1936052A (en) Aluminium-silicon alloy casting and its preparing method
CN1526843A (en) Austenic cast iron with low Al and Ni content and medium Mn content and its production process
CN101871068B (en) High-strength high-plasticity magnesium alloy comprising tin and aluminium and preparation method thereof
CN107267825B (en) Casting Al-Cu alloy material and its application
CN105950929B (en) Hypereutectic Al Si alloys and magnesium alloy hybrid engine cylinder body and its casting method
KR20080041364A (en) Development of casted aluminum liner for engine block by using p-sr- tib2 treatment

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant