High-silicon wear-resistant aluminum alloy, preparation method thereof and application thereof

Abstract

The application provides a high-silicon wear-resistant aluminum alloy, which comprises the following components: Si 25-35wt%, Cu 4-6.5wt%, Mg 1-5wt%, V 0.5-1.0wt%, Sn 0.1-0.5wt%, Zr 0.15-0.35wt%, Mo 0.05-0.15wt%, and Al as the balance. The application further provides a preparation method and application of the high-silicon wear-resistant aluminum alloy. The aluminum alloy has excellent strength, hardness, corrosion resistance and wear resistance by adding the above alloy elements and adjusting the content of the alloy elements.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and in particular to a high-silicon wear-resistant aluminum alloy, its preparation method, and its application. Background Technology

[0002] Currently, cylinder liners are generally made of cast iron. However, due to the weight of cast iron, it doesn't contribute to weight reduction, energy conservation, or emission reduction. Furthermore, the significant difference in thermal expansion coefficient between cast iron cylinder liners and aluminum alloy pistons can lead to inconsistent expansion during heating, resulting in air leakage due to misalignment. The main methods for producing aluminum alloy cylinder liners include powder metallurgy and spray deposition, with some centrifugal casting methods, but these typically employ electromagnetic treatment to homogenize the molten aluminum.

[0003] Patent CN101709414B discloses a high-silicon gradient composite aluminum alloy cylinder liner material and its preparation method. The weight percentage composition of this cylinder liner material is: Si 13.0%-27%, Fe 0.3%-2.0%, Ni 1.5%-5%, Cu 1.5%-4.0%, Mg 0.3%-0.8%, Mn 0.3%-0.8%, V 0.1%-0.5%, Sr 0.05%-0.1%, RE 0.04%-0.1%, P 0.01-0.1%, with the balance being Al. The formulation of this aluminum alloy cylinder liner is complex, and the amount of the precious element Ni is relatively large, resulting in high production costs. Furthermore, the tensile strength and other mechanical properties of the prepared cylinder liner need further improvement. Patent CN107779696A discloses a multi-element alloyed aluminum alloy material, a cylinder liner, and its preparation method. The weight percentage composition of the cylinder liner material is: silicon 20% to 30%, magnesium 3.5% to 10%, titanium 0.1% to 1%, zirconium 0.1% to 1.5%, with the balance being aluminum. It is produced by casting under the action of a magnetic field. Due to the presence of a strong magnetic field, it seriously affects the environment. At the same time, the aluminum alloy itself has poor wear resistance. Patent CN105603266A discloses an aluminum alloy cylinder liner for automobile engines and its manufacturing method. The liner is composed of an aluminum alloy matrix made of aluminum alloy comprising the following components by weight percentage: Si: 13%–15%; Cu: 1%–2%; Mg: 0.2%–0.5%; Mn: 0.1%–0.3%; Cr: 0.1%–0.3%; C: 0.1%–0.3%; Zn: 0–0.5%; Ti: 0–0.15%; RE: 0.1%–0.3%; with the remainder being Al. The surface is chrome-plated to increase wear resistance. It is produced using a die-casting method, but the pressing process is difficult to operate and has low efficiency.

[0004] Therefore, it is of great significance to provide a lightweight cylinder liner made of high wear-resistant aluminum alloy to achieve the weight reduction of the cylinder liner and thus improve the overall material performance. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a high-silicon wear-resistant aluminum alloy with excellent strength, hardness and wear resistance.

[0006] In view of this, this application provides a high-silicon wear-resistant aluminum alloy comprising: Si 25-35 wt%, Cu 4-6.5 wt%, Mg 1-5 wt%, V 0.5-1.0 wt%, Sn 0.1-0.5 wt%, Zr 0.15-0.35 wt%, Mo 0.05-0.15 wt%, and Al balance.

[0007] Preferably, the Si content is 26wt% to 32wt%.

[0008] Preferably, the content of Cu is 4.5–6.0 wt%, the content of Mg is 1.5–4.0 wt%, the content of V is 0.6–0.9 wt%, the content of Sn is 0.2–0.4 wt%, and the content of Zr is 0.2–0.3 wt%.

[0009] This application also provides a method for preparing the aforementioned high-silicon wear-resistant aluminum alloy, comprising the following steps:

[0010] A) Mix the raw materials according to the composition ratio of high-silicon wear-resistant aluminum alloy, melt them, and then add refining agent to obtain molten aluminum;

[0011] B) The molten aluminum is transferred to a heat preservation furnace for heat preservation, and after the modification treatment, it is stirred by ultrasonic waves and then cast to obtain a casting;

[0012] C) The casting is air-cooled and then aged to obtain a high-silicon wear-resistant aluminum alloy.

[0013] Preferably, the melting step specifically includes:

[0014] Aluminum ingots and aluminum-tin master alloys are melted at 700–730°C, and then heated to 750–800°C to add aluminum-silicon master alloys, aluminum-vanadium master alloys, aluminum-zirconium master alloys, aluminum-magnesium master alloys, and aluminum-molybdenum master alloys until they are melted again.

[0015] Preferably, the refining agent is C6Cl6, and its addition amount is 0.2 to 0.8 wt% of the mass of the molten aluminum obtained by remelting.

[0016] Preferably, the heat preservation temperature is 800-850℃, the modifier for the modification treatment is cerium, and its addition amount is 0.5-1.0 wt% of the mass of molten aluminum; the frequency of the ultrasonic wave is 20-25 kHz, and the duration is 10-20 min.

[0017] Preferably, the casting is carried out in a fully automatic multi-station casting machine, the casting temperature is 700-800℃, the casting machine speed is 2000-4000 r / min, and the outlet temperature is 300-400℃.

[0018] Preferably, the air cooling temperature is 200-250℃, and the aging temperature is 100-180℃; the aging treatment involves pushing the air-cooled casting into a tunnel furnace for heat preservation along with a conveyor belt, wherein the length of the tunnel furnace is L (m), the moving speed is V (m / min), and L / V≥180.

[0019] This application also provides a high-silicon wear-resistant aluminum alloy cylinder liner, comprising the composition of the high-silicon wear-resistant aluminum alloy or the high-silicon wear-resistant aluminum alloy prepared by the preparation method described above.

[0020] This application provides a high-silicon wear-resistant aluminum alloy comprising specific components of aluminum, silicon, copper, molybdenum, magnesium, vanadium, tin, and zirconium. The high silicon content, occurring in a eutectic state, is beneficial for improving the hardness, corrosion resistance, and wear resistance of the aluminum alloy. The addition of copper further enhances the strength and corrosion resistance of the aluminum alloy. Magnesium improves the alloy's corrosion resistance while refining the grain size and increasing strength. Molybdenum reduces the harmful effects of acicular iron phases. Vanadium refines the recrystallized grains and increases strength, thereby improving the wear and corrosion resistance of the aluminum alloy. The addition of zirconium refines the recrystallized grains. Therefore, by adding the above alloying elements and adjusting their content, this application obtains an aluminum alloy with excellent strength, hardness, corrosion resistance, and wear resistance.

[0021] This application also provides a method for preparing a high-silicon wear-resistant aluminum alloy, which improves the performance of the aluminum alloy by smelting the aluminum alloy and adding different alloying elements. The molten aluminum in the holding furnace is purified, and ultrasonic treatment is introduced, which can achieve the effects of grain refinement, microstructure homogenization and purification of molten aluminum. Finally, air cooling and aging are used to ensure the uniformity and refinement of the aluminum alloy microstructure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process for preparing high-silicon wear-resistant aluminum alloy according to the present invention;

[0023] Figure 2 A schematic diagram of the ultrasonic equipment used in this invention to prepare high-silicon wear-resistant aluminum alloy;

[0024] Figure 3A photograph (100×) of the microstructure of the high-silicon wear-resistant aluminum alloy matrix prepared in Example 1 of the present invention. Detailed Implementation

[0025] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.

[0026] To better conserve resources, engines are increasingly moving towards lightweight designs, leading to the concept of lightweight cylinder liners. To achieve this, the material of the cylinder liner needs improvement. Replacing iron alloy with aluminum alloy to reduce weight is a good approach. However, ensuring that the strength, hardness, and wear resistance are not compromised while reducing weight is fundamental to maintaining performance. This application provides a high-silicon wear-resistant aluminum alloy with strength, hardness, wear resistance, and corrosion resistance comparable to cast iron alloys. Furthermore, some properties, such as thermal conductivity and expansion properties, are superior to cast iron cylinder liners (the thermal conductivity of alloy cast iron is 35-45 W / (m·K) at 25℃; the coefficient of thermal expansion of alloy cast iron is 11-13 μm / (m·℃) at 25℃). Being an aluminum alloy, it also provides better fit with the piston. Specifically, this invention discloses a high-silicon wear-resistant aluminum alloy comprising: Si 25-35 wt%, Cu 4-6.5 wt%, Mg 1-5 wt%, V 0.5-1.0 wt%, Sn... 0.1-0.5 wt%, Zr 0.15-0.35 wt%, Mo 0.05-0.15 wt%, Al balance.

[0027] In high-silicon wear-resistant aluminum alloys, the silicon content is relatively high and it is in a eutectic state. Its distribution directly determines the strength and hardness of the aluminum-silicon alloy, as well as its casting performance and wear resistance. The silicon content is 25-35 wt%, specifically 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, or 35 wt%.

[0028] The addition of copper can improve the strength and corrosion resistance of aluminum alloys, thereby enhancing their solid solution strengthening and failure strengthening properties. The copper content is 4–6.5 wt%, specifically, the copper content is 4 wt%, 4.1 wt%, 4.2 wt%, 4.3 wt%, 4.4 wt%, 4.5 wt%, 4.6 wt%, 4.7 wt%, 4.8 wt%, 4.9 wt%, 5.0 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6.0 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, or 6.5 wt%.

[0029] Adding a certain amount of magnesium can improve the corrosion resistance of aluminum alloys, while refining the grains and increasing strength. The magnesium content is 1-5 wt%, specifically 1.1 wt%, 1.5 wt%, 1.7 wt%, 1.8 wt%, 2.0 wt%, 2.1 wt%, 2.3 wt%, 2.4 wt%, 2.6 wt%, 2.7 wt%, 2.9 wt%, 3.2 wt%, 3.3 wt%, 3.5 wt%, 3.7 wt%, 3.8 wt%, 4.0 wt%, 4.2 wt%, 4.3 wt%, 4.5 wt%, 4.7 wt%, 4.9 wt%, or 5.0 wt%.

[0030] To prevent the harmful effects of the ferrous phase, a certain amount of molybdenum is added, which can transform the acicular ferrous phase into a spherical one, thereby reducing the harmful effects of the acicular ferrous phase. The molybdenum content is 0.05–0.15 wt%, specifically 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, 0.13 wt%, 0.14 wt%, or 0.15 wt%.

[0031] Vanadium can refine recrystallized grains and increase strength, thereby improving the wear resistance and corrosion resistance of aluminum alloys. The vanadium content is 0.5 to 1.0 wt%, specifically, the vanadium content is 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1.0 wt%.

[0032] To improve the machinability of high-silicon aluminum alloys, a certain amount of tin was added, which greatly improved the machinability of the aluminum-silicon alloys. The tin content was 0.1–0.5 wt%, specifically 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, or 0.5 wt%.

[0033] To prevent recrystallization and refine the recrystallized grains, this application incorporates zirconium at a content of 0.15–0.35 wt%, specifically, the zirconium content is 0.15 wt%, 0.16 wt%, 0.17 wt%, 0.18 wt%, 0.19 wt%, 0.20 wt%, 0.21 wt%, 0.22 wt%, 0.23 wt%, 0.24 wt%, 0.25 wt%, 0.26 wt%, 0.27 wt%, 0.28 wt%, 0.30 wt%, 0.31 wt%, 0.32 wt%, 0.33 wt%, 0.34 wt%, or 0.35 wt%.

[0034] Furthermore, this application also provides a method for preparing high-silicon wear-resistant aluminum alloy, which includes sequentially performing aluminum molten metal smelting, refining treatment, transfer to a holding furnace, modification treatment, ultrasonic treatment, casting, forming, air cooling, and aging treatment, as detailed in the following process: Figure 1 As shown, it specifically includes the following steps:

[0035] A) Mix the raw materials according to the composition ratio of high-silicon wear-resistant aluminum alloy, melt them, and then add refining agent to obtain molten aluminum;

[0036] B) The molten aluminum is transferred to a heat preservation furnace for heat preservation, a modifier is added, and then ultrasonic stirring is used. Finally, it is cast to obtain a casting.

[0037] C) The casting is air-cooled and then aged to obtain a high-silicon wear-resistant aluminum alloy.

[0038] In the aluminum alloy preparation process, this application first mixes and melts the raw materials according to the composition ratio of high-silicon wear-resistant aluminum alloy, and then adds a refining agent to obtain molten aluminum; in this process, in order to avoid premature addition and burn-off of some metal elements, the specific mixing and melting process is as follows:

[0039] Aluminum ingots and aluminum-tin master alloys are first melted, then heated and aluminum-silicon, aluminum-vanadium, aluminum-zirconium, aluminum-magnesium and aluminum-molybdenum are added and melted again. Then, refining agents are added for refining, and the mixture is kept at a constant temperature to obtain molten aluminum.

[0040] In the above process, the initial melting temperature is 700-730℃, the reheating temperature is 750-800℃, the refining agent is C6Cl6, and its addition amount is 0.3-0.6wt% of the remelted aluminum molten material. The holding time is 10-20min.

[0041] This application preferably involves removing slag from the molten aluminum to ensure it is free of impurities such as aluminum slag. The molten aluminum is then transferred to a holding furnace using a transfer container, held at a certain temperature, and then subjected to a modification treatment followed by ultrasonic stirring. In this process, the holding temperature is 800–850°C, the modification agent for the modification treatment is rare earth cerium, added at 0.5–0.8 wt% of the molten aluminum; the ultrasonic frequency is 20–25 kHz, and the stirring time is 10–20 min. Specifically, the holding temperature is 810–840°C, the modification agent for the modification treatment is rare earth cerium, added at 0.6–0.7 wt% of the molten aluminum; the ultrasonic frequency is 21–23 kHz, and the stirring time is 12–18 min. In this application, the ultrasonic device used for ultrasonic stirring is specifically as follows: Figure 2 As shown, 1 is the ultrasonic transmitter, 2 is the amplitude transformer, 3 is the transducer, 4 is the ultrasonic power source, 5 is the movable support, 6 is the front-to-back moving track, 7 is the up-and-down moving piston, 8 is molten aluminum, and 9 is the heat preservation furnace. The working principle of the ultrasonic device is as follows: After the molten aluminum is completely dissolved, the ultrasonic device is moved along the front-to-back moving track 6 to the heat preservation furnace 9. By controlling the liftable support 5, the ultrasonic transmitter 1 of the ultrasonic device is inserted into the molten aluminum 8 within a range of 10-15 cm below the surface. At this time, the ultrasonic power source 4 is turned on and the required frequency is adjusted. The ultrasonic waves pass through the transducer 3 (with circulating water for cooling flowing through it), and the amplitude transformer 2 drives the ultrasonic transmitter 1 to generate ultrasonic vibration, thereby making the molten aluminum uniform and cavitating the air bubbles in it, thus achieving the purpose of purifying the molten aluminum.

[0042] Therefore, after the aluminum molten metal undergoes thermal insulation and modification treatment, ultrasonic treatment improves the alloy's properties due to the cavitation and acoustic flow effects of ultrasound. Ultrasound mainly affects the alloy's microstructure and properties through the following aspects: 1) Grain refinement: Ultrasound has two effects on the crystallization process: one is the effect on the growth of crystals in supersaturated solutions, and the other is the effect on the crystal structure during metal solidification. Due to the action of ultrasound, the formation of crystal nuclei in the solution is accelerated and the growth of crystals is inhibited, resulting in finer and more uniform grains. This is because the cavitation effect breaks down and disperses the crystal clusters and dendritic grains into more new crystal nuclei, thereby significantly improving the properties; 2) Microstructure homogenization: Due to the action of ultrasound, the elements in the solution can be evenly distributed, reducing element and microstructure segregation, thereby significantly improving tensile strength, yield strength, and corrosion resistance; 3) Ultrasonic degassing and slag removal: Gases dissolved in the liquid grow and aggregate into large bubbles under the vibration of ultrasound, rising to the liquid surface and escaping.

[0043] According to the present invention, a protective atmosphere is required in all of the above-mentioned melting, purification, transfer and heat preservation processes, specifically under argon protection.

[0044] This application then pours the purified molten aluminum to obtain castings. During the pouring process, an automatic multi-station casting machine is used. The casting machine employs a conventional centrifugal casting process with wet coating in a metal mold to produce cylinder liner castings. The multi-station casting machine includes steps such as automatic spraying, upper baffle, pouring, water quenching, cooling, and automatic cylinder discharge. The pouring temperature is 700–800℃, specifically 720–780℃; the casting machine speed is 2000–4000 r / min, specifically 2400–3500 r / min; the water quenching time is 8–18 s, specifically 10–15 s; the mold is preheated and maintained at 150–250℃; the cylinder discharge temperature is 300–380℃, specifically 320–350℃.

[0045] This application then air-cools the obtained castings and performs aging treatment to obtain a high-silicon wear-resistant aluminum alloy. The air-cooling of the castings is carried out on a conveyor belt, with the air cooling temperature reduced to 200–250°C, specifically 210–240°C. After air cooling, the castings are advanced by the conveyor belt into a tunnel furnace for heat preservation. The tunnel furnace temperature is 100–180°C, the length of the tunnel furnace is L (m), and the moving speed is V (m / min), ensuring that L / V ≥ 180.

[0046] This application also provides a high-silicon wear-resistant aluminum alloy cylinder liner, the composition of which is as described above for the high-silicon wear-resistant aluminum alloy or prepared according to the above method.

[0047] To further understand the present invention, the preparation method of the high-silicon aluminum alloy cylinder liner provided by the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0048] Example 1

[0049] A manufacturing process for a high-strength and high-wear-resistant lightweight aluminum alloy cylinder liner includes the following steps:

[0050] 1. Cylinder liner blank production

[0051] ① Aluminum molten metal smelting: Aluminum ingots and aluminum-tin master alloys are melted at 720℃, and then the temperature is raised to 780℃. Aluminum-silicon, aluminum-vanadium, aluminum-zirconium, aluminum-magnesium, and aluminum-molybdenum master alloys are added and the process continues until melting. Then, refining agent C6Cl6 is added at a rate of 0.5% of the mass of the aluminum molten metal, and the temperature is maintained for 10 minutes. The composition of the aluminum molten metal is shown in Table 1.

[0052] Table 1. Aluminum molten metal composition data.

[0053]

[0054] ② Aluminum molten metal transfer and holding furnace: The molten aluminum is slag removed to ensure that there are no slag or other impurities in the aluminum molten metal. The aluminum molten metal is transferred to the holding furnace using a transfer bag. The temperature of the holding furnace is controlled at 820℃. Rare earth cerium modifier is added at a rate of 0.65% of the mass of aluminum molten metal.

[0055] ③ Argon gas protection is required during the smelting, purification, transfer and heat preservation processes;

[0056] ④ Casting: Production is carried out using a fully automatic multi-station casting machine. The casting machine adopts the conventional process of centrifugal casting with wet coating in metal mold to produce cylinder liner castings. The multi-station casting machine includes steps such as automatic spraying, upper baffle, pouring, water quenching, cooling and automatic cylinder discharge. The pouring temperature is controlled at 760℃, the casting machine speed is 2600r / min, the water quenching time is 15S, the mold is preheated and maintained at 210℃, and the cylinder discharge temperature is 350℃.

[0057] ⑤ Air cooling: The cylinder liners coming out of the automatic casting machine are automatically placed on the conveyor belt and cooled down to 224℃ by blowing air through a fan;

[0058] ⑥ Aging treatment: After being cooled by air cooling, the cylinder liner is pushed into the tunnel furnace for heat preservation as the conveyor belt advances. The temperature of the tunnel furnace is controlled at 160℃ and the heat preservation in the tunnel furnace is 180 minutes.

[0059] Paint cleaning: The cylinder liner coming out of the tunnel furnace is cleaned by an automatic paint cleaning device;

[0060] ⑦ Framing: The cleaned cylinder liners are automatically framed by robots;

[0061] 2. Machining: Processing the blank into a finished product.

[0062] Figure 3 This is a micrograph of the aluminum alloy cylinder liner substrate prepared in this embodiment. Figure 3 It can be seen that the silicon phase is uniformly distributed in the aluminum phase, and the structure is relatively uniform.

[0063] Example 2

[0064] A manufacturing process for a high-strength and high-wear-resistant lightweight aluminum alloy cylinder liner includes the following steps:

[0065] The preparation process is the same as in Example 1, except that: after adding the modifier rare earth cerium during the heat preservation process, ultrasonic treatment is added. The specific method is as follows: move the ultrasonic treatment device above the heat preservation furnace, open the furnace cover, insert the ultrasonic frequency conversion rod into the solution within a range of 10-15cm, and turn on ultrasonic stirring for 10min. At this time, the ultrasonic frequency is set to 23KHz.

[0066] Example 3

[0067] 1. Cylinder liner production:

[0068] ① Aluminum molten metal smelting: Aluminum ingots and aluminum-tin master alloys are melted at 708℃, and then aluminum-silicon, aluminum-vanadium, aluminum-zirconium, aluminum-magnesium, and aluminum-molybdenum master alloys are pressed into the mixture at 790℃ until it melts. Then, refining agent C6Cl6 is added at a rate of 0.35% of the mass of the aluminum molten metal, and the mixture is held at this temperature for 10 minutes. The composition of the aluminum molten metal is shown in Table 2.

[0069] Table 2. Aluminum molten metal composition data.

[0070]

[0071] ② Aluminum molten metal transfer and holding furnace: The molten aluminum is slag-removed to ensure that there are no aluminum slag or other impurities in the aluminum molten metal. The aluminum molten metal is transferred to the holding furnace using a transfer bag. The temperature of the holding furnace is controlled within the range of 838℃. Rare earth cerium modifier is added at a rate of 0.70% of the mass of aluminum molten metal. The ultrasonic treatment device is moved above the holding furnace, the furnace cover is opened, and the ultrasonic frequency conversion rod is inserted into the solution within a range of 10-15cm. The ultrasonic stirring is turned on for 10 minutes. At this time, the frequency of the ultrasonic wave is set to 21KHz.

[0072] ③ Argon gas protection is required during the smelting, purification, transfer and heat preservation processes;

[0073] ④ Casting: Production is carried out using a fully automatic multi-station casting machine. The casting machine adopts the conventional process of centrifugal casting with wet coating in metal mold to produce cylinder liner castings. The multi-station casting machine includes steps such as automatic spraying, upper baffle, pouring, water quenching, cooling and automatic cylinder discharge. The pouring temperature is controlled at 736℃, the casting machine speed is 2860r / min, the water quenching time is 10s, the mold is preheated and maintained at 185℃, and the cylinder discharge temperature is 370℃.

[0074] ⑤ Air cooling: The cylinder liners coming out of the automatic casting machine are automatically placed on the conveyor belt and cooled down to 240℃ by blowing air through a fan;

[0075] ⑥ Aging treatment: After the cylinder liner has been cooled by air cooling, it is pushed into the tunnel furnace for heat preservation as the conveyor belt advances. The temperature of the tunnel furnace is controlled at 130℃ and the heat preservation treatment in the tunnel furnace is 210 minutes.

[0076] Paint cleaning: The cylinder liner coming out of the tunnel furnace is cleaned by an automatic paint cleaning device;

[0077] ⑦ Framing: The cleaned cylinder liners are automatically framed by robots;

[0078] 2. Machining: Processing the blank into a finished product.

[0079] Example 4

[0080] 1. Cylinder liner production:

[0081] ① Aluminum molten metal smelting: Aluminum ingots and aluminum-tin master alloys are melted at 729℃, and then the temperature is raised to 755℃ and aluminum-silicon, aluminum-vanadium, aluminum-zirconium, aluminum-magnesium, and aluminum-molybdenum master alloys are pressed in until melted. Then, refining agent C6Cl6 is added at a rate of 0.58% of the mass of aluminum molten metal, and the temperature is maintained for 10 minutes. The composition of aluminum molten metal is shown in Table 3.

[0082] Table 3. Aluminum molten metal composition data.

[0083]

[0084] ② Aluminum molten metal transfer and holding furnace: The molten aluminum is slag-removed to ensure that there are no aluminum slag or other impurities in the aluminum molten metal. The aluminum molten metal is transferred to the holding furnace using a transfer bag. The temperature of the holding furnace is controlled within the range of 808℃. Rare earth cerium modifier is added at a rate of 0.55% of the mass of aluminum molten metal. The ultrasonic treatment device is moved above the holding furnace, the furnace cover is opened, and the ultrasonic frequency converter is inserted into the solution within a range of 10-15cm. The ultrasonic stirring is turned on for 10 minutes. At this time, the frequency of the ultrasonic wave is set to 25KHz.

[0085] ③ Argon gas protection is required during the smelting, purification, transfer and heat preservation processes;

[0086] ④ Casting: Production is carried out using a fully automatic multi-station casting machine. The casting machine adopts the conventional process of centrifugal casting with wet coating in metal mold to produce cylinder liner castings. The multi-station casting machine includes steps such as automatic spraying, upper baffle, pouring, water quenching, cooling and automatic cylinder discharge. The casting temperature is controlled at 790℃, the casting machine speed is 2350r / min, the water quenching time is 16s, the mold is preheated and maintained at 176℃, and the cylinder discharge temperature is 320℃.

[0087] ⑤ Air cooling: The cylinder liners coming out of the automatic casting machine are automatically placed on the conveyor belt and cooled down to 215℃ by blowing air through a fan.

[0088] ⑥ Aging treatment: After the cylinder liner has been cooled by air, it is pushed into the tunnel furnace for heat preservation as the conveyor belt advances. The temperature of the tunnel furnace is controlled at 150℃ and the heat preservation in the tunnel furnace is 240 minutes.

[0089] Paint cleaning: The cylinder liner coming out of the tunnel furnace is cleaned by an automatic paint cleaning device;

[0090] ⑦ Framing: The cleaned cylinder liners are automatically framed by robots;

[0091] 3. Machining: Processing the blank into a finished product.

[0092] Example 5

[0093] 1. Cylinder liner production:

[0094] ① Aluminum molten metal smelting: Aluminum ingots and aluminum-tin master alloys are melted at 720℃, and then the temperature is raised to 780℃ and aluminum-silicon, aluminum-vanadium, aluminum-zirconium, aluminum-magnesium, and aluminum-molybdenum master alloys are pressed in until melted; then refining agent C6Cl6 is added at 0.50% of the mass of aluminum molten metal, and the temperature is held for 10 minutes; the composition of aluminum molten metal is shown in Table 4.

[0095] Table 4. Aluminum molten metal composition data.

[0096]

[0097] ② Aluminum molten metal transfer and holding furnace: The molten aluminum is slag removed to ensure that there are no aluminum slag or other impurities in the aluminum molten metal. The aluminum molten metal is transferred to the holding furnace using a transfer bag. The temperature of the holding furnace is controlled within the range of 830℃. Rare earth cerium modifier is added at a rate of 0.65% of the mass of aluminum molten metal. At this time, it is stirred with an ultrasonic stirrer for 10 minutes at a frequency of 22KHz.

[0098] ③ Argon gas protection is required during the smelting, purification, transfer and heat preservation processes;

[0099] ④ Casting: Production is carried out using a fully automatic multi-station casting machine. The casting machine adopts the conventional process of centrifugal casting with wet coating in metal mold to produce cylinder liner castings. The multi-station casting machine includes steps such as automatic spraying, upper baffle, pouring, water quenching, cooling and automatic cylinder discharge. The pouring temperature is controlled at 780℃, the casting machine speed is 2500r / min, the water quenching time is 12s, the mold is preheated and maintained at 200℃, and the cylinder discharge temperature is 350℃.

[0100] ⑤ Air cooling: The cylinder liners coming out of the automatic casting machine are automatically placed on the conveyor belt and cooled down to 230℃ by blowing air through a fan;

[0101] ⑥ Aging treatment: After the cylinder liner has been cooled by air, it is pushed into the tunnel furnace by the conveyor belt and then kept warm. The temperature of the tunnel furnace is controlled at 150℃ and kept warm in the tunnel furnace for 200 minutes.

[0102] Paint cleaning: The cylinder liner coming out of the tunnel furnace is cleaned by an automatic paint cleaning device;

[0103] ⑦ Framing: The cleaned cylinder liners are automatically framed by robots;

[0104] 4. Machining: Processing the blank into finished products.

[0105] Comparative Example 1

[0106] Except for the following contents, the rest is the same as in Example 5; the composition of molten aluminum is shown in Table 5;

[0107] Table 5. Aluminum molten metal composition data.

[0108] Item Si Cu Mg V Sn Zr Require 30％ 4.8％ 3.8％ 0.72％ 0.35％ 0.22％

[0109] Comparative Example 2

[0110] Except for the following contents, the rest is the same as in Example 5; the composition of molten aluminum is shown in Table 6;

[0111] Table 6. Aluminum molten metal composition data.

[0112] Item Si Cu Mg V Zr Mo Require 30％ 4.8％ 3.8％ 0.72％ 0.22％ 0.105％

[0113] The performance of the aluminum alloy cylinder liners prepared in the examples and comparative examples was tested.

[0114] The hardness test method adopted is GB / T230.1-2018 Rockwell hardness test method for metallic materials;

[0115] The tensile strength test method is GB / T228.1 Metallic materials, tensile test method at room temperature; the wear resistance test is conducted using a reciprocating friction tester with the following parameters: stroke 10mm, frequency 10Hz, load 5Kg, temperature room temperature, test time 1 hour, and alloy steel balls as the grinding material.

[0116] Thermal conductivity was determined using the standard test method of ASTM E1461-01 laser method for determining thermal diffusivity, and thermal expansion coefficient was determined using GB / T4339-2008 Test method for thermal expansion characteristics of metallic materials.

[0117] The cutting performance was determined by fixing machine tool parameters (machine speed, feed rate), turning length, and the wear of the tool after machining 24 cylinder liners.

[0118] The performance test results of the examples and comparative examples are shown in Tables 7, 8 and 9;

[0119] Table 7 shows the test results of various performance parameters for aluminum alloy cylinder liners in Examples 1-5.

[0120] serial number Tensile strength (MPa) Hardness (HBW) Total wear and tear (mg) Average coefficient of friction Example 1 285 187 0.01212 1.03 Example 2 420 215 0.01031 1.07 Example 3 408 210 0.01028 1.12 Example 4 436 235 0.01002 1.05 Example 5 425 230 0.01035 1.06

[0121] Example 1 was not subjected to ultrasonic treatment, and its strength was significantly lower than that of Examples 2-5. Furthermore, the wear of the cylinder liners prepared in Examples 2-4 was significantly less than that in Example 1.

[0122] Table 8. Data on the iron phase structure and machinability of cylinder liners in Example 5 and Comparative Examples 1-2.

[0123] serial number iron phase Wear amount (μm) of 24 cutting tool tips Comparative Example 1 Needle-like iron phase structures were present in some fields of view. 100 Comparative Example 2 No needle-like or strip-like iron phase structures were found. 170 Example 5 No needle-like or strip-like iron phase structures were found. 95

[0124] Comparative Example 1 did not add molybdenum. Since molybdenum can suppress the formation of impurity iron phase, a trace amount of iron phase was present. However, in Example 5 and Comparative Example 2, molybdenum was added, and no needle-like or strip-like iron phase structure was found. Comparative Example 2 did not add tin, which made it more difficult to process and caused faster tool wear.

[0125] Table 9. Test results of thermal properties of aluminum alloy cylinder liners in Examples 1-5

[0126] serial number Thermal conductivity (w / (k*m)) Coefficient of thermal expansion (μm / (m·℃)) Example 1 16.2 160 Example 2 16.0 158 Example 3 15.8 167 Example 4 15.8 162 Example 5 15.9 159

[0127] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0128] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-silicon wear-resistant aluminum alloy, comprising: Si 28~35wt%, Cu 4~6.5wt%, Mg 1.55~5wt%, V 0.5~1.0wt%, Sn 0.1~0.5wt%, Zr 0.15~0.35wt%, Mo 0.05~0.15wt%, Al balance; The preparation method of the high-silicon wear-resistant aluminum alloy includes the following steps: A) Mix the raw materials according to the composition ratio of high silicon wear-resistant aluminum alloy, melt them, and then add refining agent C6Cl6 to obtain molten aluminum; B) The molten aluminum is transferred to a heat-holding furnace for heat treatment, and after modification treatment, it is stirred with ultrasonic waves and then cast to obtain a casting; the modifier for modification treatment is cerium; the heat treatment temperature is 800~850℃; the casting is carried out in a fully automatic multi-station casting machine, the casting temperature is 700~800℃, the casting machine speed is 2000~4000r / min, and the outlet temperature is 300~400℃; C) The casting is air-cooled and then aged to obtain a high-silicon wear-resistant aluminum alloy.

2. The high-silicon wear-resistant aluminum alloy according to claim 1, characterized in that, The content of Cu is 4.5~6.0 wt%, the content of Mg is 1.55~4.0 wt%, the content of V is 0.6~0.9 wt%, the content of Sn is 0.2~0.4 wt%, and the content of Zr is 0.2~0.3 wt%.

3. The method for preparing the high-silicon wear-resistant aluminum alloy according to claim 1, comprising the following steps: A) Mix the raw materials according to the composition ratio of high silicon wear-resistant aluminum alloy, melt them, and then add refining agent C6Cl6 to obtain molten aluminum; B) The molten aluminum is transferred to a heat-holding furnace for heat treatment, and after modification treatment, it is stirred with ultrasonic waves and then cast to obtain a casting; the modifier for modification treatment is cerium; the heat treatment temperature is 800~850℃; the casting is carried out in a fully automatic multi-station casting machine, the casting temperature is 700~800℃, the casting machine speed is 2000~4000r / min, and the outlet temperature is 300~400℃; C) The casting is air-cooled and then aged to obtain a high-silicon wear-resistant aluminum alloy.

4. The preparation method according to claim 3, characterized in that, The melting step specifically involves: Aluminum ingots and aluminum-tin master alloys are melted at 700~730℃, and then heated to 750~800℃ to add aluminum-silicon master alloys, aluminum-vanadium master alloys, aluminum-zirconium master alloys, aluminum-magnesium master alloys, and aluminum-molybdenum master alloys until they are melted again.

5. The preparation method according to claim 4, characterized in that, The amount of the refining agent added is 0.2 to 0.8 wt% of the mass of the molten aluminum obtained by remelting.

6. The preparation method according to claim 3, characterized in that, The amount of cerium added is 0.5~1.0 wt% of the mass of the molten aluminum; the frequency of the ultrasound is 20~25 kHz, and the duration is 10~20 min.

7. The preparation method according to claim 3, characterized in that, The air cooling temperature is 200~250℃, and the aging temperature is 100~180℃. The aging treatment involves pushing the air-cooled casting into a tunnel furnace for heat preservation along with a conveyor belt. The length of the tunnel furnace is L (m), the moving speed is V (m / min), and L / V≥180.

8. A high-silicon wear-resistant aluminum alloy cylinder liner, comprising the composition of the high-silicon wear-resistant aluminum alloy as described in any one of claims 1 to 2 or the high-silicon wear-resistant aluminum alloy prepared by the preparation method as described in any one of claims 3 to 7.

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