In-situ TiB2 particle near-equiaxed control technology and extrusion casting forming technology of aluminum-based composite material of in-situ TiB2 particle near-equiaxed control technology

Abstract

The invention relates to the technical field of aluminum alloy pressure casting composite materials, in particular to an in-situ TiB2 particle near-equiaxed control technology and an extrusion casting forming technology of an aluminum matrix composite material of the in-situ TiB2 particle near-equiaxed control technology. The method comprises the following steps: melting an Al-15Ti intermediate alloy, an Al-8B intermediate alloy and an industrial aluminum alloy together, and carrying out ultrasonic treatment after melting; al-10Sc intermediate alloy is added for continuous melting, and ultrasonic treatment is carried out after melting; argon is introduced to carry out rotary blowing treatment on the smelting liquid, then ultrasonic treatment is carried out, and aluminum alloy smelting liquid is obtained; and the aluminum alloy smelting solution is subjected to extrusion casting, and the TiB2 particle reinforced aluminum-based composite material is obtained. According to the method, collaborative optimization regulation and control of the size and morphology of the TiB2 particles are achieved by controlling the B / Ti ratio, reducing the reaction temperature and adding microalloy elements, the melt quality is ensured in cooperation with ultrasonic treatment and argon rotary injection, and finally production and manufacturing of the TiB2 particle reinforced aluminum matrix composite casting are achieved through the optimized extrusion casting technology.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy pressure casting composite material technology, and in particular to an in-situ TiB2 particle near-equiaxed control technology and its aluminum-based composite material extrusion casting forming process. Background Technology

[0002] Particle-reinforced aluminum matrix composites combine the high strength and hardness of the particle-reinforcing phase with the softness and toughness of the aluminum matrix, resulting in a lightweight, high-strength material with excellent comprehensive properties. They are currently widely used in aerospace, automotive manufacturing, and weaponry. Among commonly used ceramic particle-reinforcing phases, TiB2 particles possess outstanding advantages such as good wettability with the aluminum matrix, strong interfacial bonding, and no reaction with the molten aluminum, allowing them to exist stably within the molten aluminum. They hold broad research and application prospects. Compared to the additive method, TiB2 particle-reinforced aluminum matrix composites prepared by the in-situ self-generation method exhibit stronger interfacial bonding between the TiB2 particles and the aluminum alloy matrix, resulting in superior strengthening effects.

[0003] However, the preparation processes of commonly used in-situ reaction methods for TiB2 particle-reinforced aluminum matrix composites are limited by the reactant raw materials and reaction system. These methods often require relatively high temperatures to ensure proper reaction. For example, the most commonly used mixed fluoride salt reaction method typically requires an in-situ reaction within the temperature range of 800–900℃ (generally 850℃) to proceed normally. This results in excessively rapid diffusion of elements during the reaction, ultimately leading to larger in-situ TiB2 particles. According to relevant strengthening theories, smaller particle sizes result in more significant strengthening effects. For aluminum alloy matrices, the size of in-situ TiB2 particles often needs to reach the nanometer scale to fully exert their strengthening effect. Furthermore, due to the close-packed hexagonal crystal structure of TiB2, the typical morphology of TiB2 particles is hexagonal lamellar particles. This can lead to stress concentration at the sharp edges of the particles, eventually propagating into crack initiation sites, thus impairing the mechanical properties of the composite material. In summary, the size and morphology of in-situ TiB2 particles are two key factors that determine their strengthening effect. Therefore, adjusting the preparation process to achieve nano-sized in-situ TiB2 particles and equiaxed morphology is currently a key research focus.

[0004] Another major advantage of particle-reinforced aluminum matrix composites is that they can be combined with liquid casting to achieve high-efficiency, low-cost large-scale casting production. However, the addition of reinforcing particles reduces the material's flowability, which affects the molding quality of composite castings and thus impairs the composite's performance. Therefore, exploring liquid forming processes that match TiB2 particle-reinforced aluminum matrix composites is also a key issue in improving their mechanical properties. Summary of the Invention

[0005] The purpose of this invention is to provide an in-situ near-equiaxed TiB2 particle control technology and an extrusion casting process for its aluminum matrix composites, in order to solve the problems of high reaction temperature leading to large in-situ TiB2 particle size and the damage to the mechanical properties of composite materials caused by hexagonal lamellar TiB2 particles in the preparation of TiB2 particle-reinforced aluminum matrix composites by traditional in-situ reaction methods, such as the mixed fluoride salt reaction method.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing TiB2 particle-reinforced aluminum matrix composites, comprising the following steps: (1) The Al-15Ti master alloy, Al-8B master alloy and industrial aluminum alloy are melted together and ultrasonically treated after melting to obtain the first molten liquid; (2) The Al-10Sc master alloy is added to the first molten liquid for melting, and then ultrasonically treated to obtain the second molten liquid; (3) After the second molten liquid is subjected to rotary blowing treatment by argon gas, it is subjected to ultrasonic treatment to obtain aluminum alloy molten liquid; (4) The aluminum alloy melt was extruded and cast to obtain TiB2 particle-reinforced aluminum matrix composite material.

[0007] Optionally, the Al-15Ti master alloy and Al-8B master alloy are prepared according to the B / Ti molar ratio; the B / Ti molar ratio is 2.2~3; the mass fraction of TiB2 particles prepared from the Al-15Ti master alloy and Al-8B master alloy in the aluminum matrix composite material is 5~10%.

[0008] Optionally, the Al-10Sc master alloy is prepared according to the designed amount of Sc element added, wherein Sc accounts for 0.1~0.5% of the mass of TiB2 particle-reinforced aluminum matrix composite material.

[0009] Optionally, the industrial aluminum alloy includes an Al-Si alloy; based on the total mass of the final TiB2 particle-reinforced aluminum matrix composite material as 100%, the amount of industrial aluminum alloy fed is the balance excluding the Al-15Ti master alloy, Al-8B master alloy, and Al-10Sc master alloy.

[0010] Optionally, in step (1), the melting temperature is 750℃, the ultrasonic frequency is 20kHz, the power is 2kw, and the time is 10~15min.

[0011] Optionally, in step (2), the temperature of the first molten liquid is 680~690℃, the frequency of the ultrasound is 20kHz, the power is 2kw, and the time is 10~15min.

[0012] Optionally, in step (3), the argon gas is introduced at a rate of 5~10 L / min, the rotation speed of the rotary jet treatment is 150~160 r / min, the temperature is 680~690℃, the time is 20~25 min, the ultrasonic frequency is 20 kHz, the power is 2 kW, and the time is 3~5 min.

[0013] Optionally, in step (4), the temperature of the aluminum alloy molten liquid is 725-730℃, the pressure of extrusion casting is 120-140MPa, the mold temperature is 230-250℃, the injection speed is 4-5mm / s, and the injection time is 20-30s.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention is based on the in-situ reaction method of intermediate alloy to synthesize in-situ TiB2 particles. Compared with traditional methods such as mixed fluoride salt reaction, this invention can achieve normal in-situ reaction at a lower temperature (680-690℃). By reducing the reaction temperature, the diffusion rate of solute elements is reduced, and the growth rate of TiB2 particles is suppressed, thereby achieving micro-nanoization of the size of in-situ TiB2 particles.

[0015] 2. This invention prepares aluminum matrix composite melt through in-situ reaction of Al-15Ti and Al-8B master alloys in a furnace, and then directly performs subsequent extrusion casting liquid forming process without the need for remelting and dilution processes. Therefore, the designable range of TiB2 particle content is wider, and it can simultaneously achieve the preparation of low mass fraction and high mass fraction TiB2 particle-reinforced aluminum matrix composites.

[0016] 3. This invention combines extrusion casting technology to prepare composite material castings. The low-speed filling and high-pressure solidification characteristics of extrusion casting technology give it a significant advantage in the preparation of TiB2 particle-reinforced aluminum matrix composites. It solves the defect of poor flowability of particle-reinforced aluminum matrix composites, while also improving the interfacial bonding strength between TiB2 particles and the aluminum matrix, thereby further improving the mechanical properties of in-situ TiB2 particle-reinforced aluminum matrix composite castings. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0018] Figure 1 This is a typical microstructure diagram of TiB2 particles with equiaxed characteristics and their extruded cast aluminum matrix composite material prepared in Example 1 of the present invention.

[0019] Figure 2This is a typical microstructure diagram of TiB2 particles in Comparative Example 4, where the equiaxed morphology control could not be achieved without the use of this invention. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0021] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0022] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0023] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0024] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0025] All raw materials used in this invention can be obtained commercially or prepared using existing technologies.

[0026] This invention provides a method for preparing TiB2 particle-reinforced aluminum matrix composites, comprising the following steps: (1) The Al-15Ti master alloy, Al-8B master alloy and industrial aluminum alloy are melted together and ultrasonically treated after melting to obtain the first molten liquid; (2) The Al-10Sc master alloy is added to the first molten liquid for melting, and then ultrasonically treated to obtain the second molten liquid; (3) After the second molten liquid is subjected to rotary blowing treatment by argon gas, it is subjected to ultrasonic treatment to obtain aluminum alloy molten liquid; (4) The aluminum alloy melt was extruded and cast to obtain TiB2 particle-reinforced aluminum matrix composite material.

[0027] Step (1) of this invention involves weighing and balancing Al-15Ti and Al-8B master alloys according to the designed different TiB2 mass fractions and B / Ti molar ratios; placing the weighed master alloys and the remaining industrial aluminum alloys into a melting furnace, heating to 750°C and holding at that temperature until completely melted, then lowering the melt temperature to 680-690°C, applying ultrasonic vibration to stir the melt, promoting the reaction, and obtaining the first molten liquid.

[0028] In this invention, the Al-15Ti master alloy and Al-8B master alloy are prepared according to the B / Ti molar ratio; the B / Ti molar ratio is 2.2~3, for example, it can be 2.2, 2.4, 2.6, 2.8 or 3, etc., and the excess B element plays a role in controlling the particle morphology as a trace element.

[0029] This invention controls the B / Ti molar ratio of the main reacting elements (2.2-3.0) to make the B element in the melt excessive. The excessive B element will inhibit the growth rate of the high index crystal planes of TiB2 particles through adsorption, thereby achieving the equiaxed morphology of the lamellar TiB2 particles and reducing the aspect ratio of the particles. This weakens the damage to the mechanical properties of the composite material caused by stress concentration at the edges of TiB2 particles.

[0030] The TiB2 particles prepared from Al-15Ti master alloy and Al-8B master alloy have a mass fraction of 5-10% in the aluminum matrix composite material, for example, 5%, 6%, 7%, 8%, 9% or 10%.

[0031] In this invention, the melting temperature in step (1) is 750°C, the ultrasonic frequency is 20kHz, the power is 2kW, and the time is 10~15min, for example, 10min, 12min, 13min or 15min.

[0032] In this invention, the industrial aluminum alloy includes Al-Si alloy; based on the total mass of the final TiB2 particle-reinforced aluminum matrix composite material as 100%, the amount of industrial aluminum alloy fed is the balance excluding Al-15Ti master alloy, Al-8B master alloy, and Al-10Sc master alloy.

[0033] Step (2) of this invention is to add the Al-10Sc master alloy weighed according to the designed different Sc element addition amount into the first molten liquid, keep it at the temperature until it is completely melted, and then apply ultrasonic vibration treatment to the melt again. The melt temperature is 680-690℃, and the geometry of the in-situ reinforcing phase is further controlled. In this invention, the Al-10Sc master alloy is prepared according to the designed amount of Sc element added, and the Sc accounts for 0.1~0.5% of the mass of TiB2 particle-reinforced aluminum matrix composite material, for example, it can be 0.1%, 0.2%, 0.3%, 0.4% or 0.5%; the trace amount of Sc element and B element synergistically regulate the morphology of TiB2 particles.

[0034] This invention introduces trace amounts of Sc elements during the in-situ reaction process by adding Al-10Sc master alloy. The presence of these trace amounts of Sc elements in the melt will also adsorb onto the high-index crystal planes of TiB2 particles, thereby inhibiting their growth. This, in conjunction with the excess B elements in the melt, achieves equiaxed morphology and further refinement of the size of the TiB2 particles.

[0035] In this invention, the temperature of the first molten liquid in step (2) is 680~690℃, preferably 680℃, the frequency of the ultrasound is 20kHz, the power is 2kw, and the time is 10~15min, for example, it can be 10min, 12min, 13min or 15min, etc.

[0036] Step (3) of this invention involves introducing high-purity argon gas to perform rotary blowing treatment on the second molten liquid to minimize the content of gas and oxide inclusions in the melt, and then removing the slag on the surface of the melt; raising the furnace temperature to the casting temperature and holding it at that temperature; and applying ultrasonic vibration treatment to enhance the dispersion and homogenization of TiB2 particles in the melt.

[0037] In this invention, in step (3), the argon gas is introduced at a rate of 5-10 L / min, the rotation speed of the rotary jet treatment is 150-160 r / min, the temperature is 680-690℃, preferably 680℃, the time is 20-25 min, preferably 25 min, the ultrasonic frequency is 20 kHz, the power is 2 kW, and the time is 3-5 min, preferably 5 min.

[0038] In step (4) of this invention, aluminum alloy molten liquid is poured into a barrel and indirectly extruded and cast to obtain TiB2 particle-reinforced aluminum matrix composite material.

[0039] In this invention, the temperature of the aluminum alloy molten liquid in step (4) is 725-730℃, preferably 730℃, the pressure of extrusion casting is 120-140MPa, for example, 120MPa, 125MPa, 130MPa, 135MPa or 140MPa, etc.; the mold temperature is 230-250℃, for example, 230℃, 240℃ or 250℃, etc.; the low speed of injection is 4-5mm / s, preferably 4mm / s; and the injection time is 20-30s, preferably 30s.

[0040] This invention proposes an in-situ near-equiaxed TiB2 particle control technology and its extrusion forming process for aluminum matrix composites. This method is based on the intermediate alloy in-situ reaction method. By controlling the molar ratio of key reaction elements B / Ti, reducing the reaction temperature, and adding microalloying elements, the size and morphology of in-situ TiB2 particles are synergistically optimized. Furthermore, online ultrasonic treatment and argon rotary blowing are used to ensure ideal melt quality. At the same time, the application of extrusion casting technology can also solve the problem of reduced flowability of TiB2 particle-reinforced aluminum matrix composites, and can improve the interfacial bonding strength between TiB2 particles and aluminum matrix, eliminate interfacial defects, and thus realize the preparation of high-strength in-situ TiB2 particle-reinforced aluminum matrix composite castings.

[0041] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0042] In an embodiment of the present invention, the Al-Si alloy is designated as AlSi10MnMg.

[0043] Example 1 This embodiment provides an extrusion casting method for preparing an in-situ near-equiaxed TiB2 particle-reinforced aluminum matrix composite material with a TiB2 mass fraction of 6%, a B / Ti molar ratio of 2.2, and a Sc element content of 0.1%. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 45.64%.

[0044] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0045] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0046] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0047] Example 2 This embodiment provides an extrusion casting method for preparing an in-situ near-equiaxed TiB2 particle-reinforced aluminum matrix composite material with a TiB2 mass fraction of 6%, a B / Ti molar ratio of 2.5, and a Sc element content of 0.3%. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 29.46%; 3) The mass fraction of Al-10Sc master alloy is 3%; 4) The mass fraction of Al-Si alloy is 40.11%.

[0048] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0049] Step (3) Extrusion Casting The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0050] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0051] Example 3 This embodiment provides an extrusion casting method for preparing an in-situ near-equiaxed TiB2 particle-reinforced aluminum matrix composite material with a TiB2 mass fraction of 10%, a B / Ti molar ratio of 2.5, and a Sc element content of 0.3%. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 45.71%; 2) The mass fraction of Al-8B master alloy is 49.11%; 3) The mass fraction of Al-10Sc master alloy is 3%; 4) The mass fraction of Al-Si alloy is 2.18%.

[0052] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 10 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0053] Step (3) Extrusion Casting The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0054] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0055] Comparative Example 1 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6% and a Sc element content of 0.1%, using conventional commercial Al-5Ti-B as raw material. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-5Ti-B master alloy is 82.3%; 2) The mass fraction of Al-10Sc master alloy is 1%; 3) The mass fraction of Al-Si alloy is 17.7%.

[0056] Step (2) Smelting 1) Weigh the Al-5Ti-B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0057] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0058] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0059] Comparative Example 2 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6% and a Sc element content of 0.1%, under the condition of a B / Ti molar ratio of 1.2. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 45.71%; 2) The mass fraction of Al-8B master alloy is 23.57%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 29.72%.

[0060] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0061] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0062] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0063] Comparative Example 3 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6% and a Sc element content of 0.1%, under the condition of a B / Ti molar ratio of 4.5. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 53.04%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 18.53%.

[0064] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0065] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0066] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0067] Comparative Example 4 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6% and a B / Ti molar ratio of 2.2 without the addition of Sc. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-Si alloy is 46.64%.

[0068] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min and keep the melt temperature at 680℃. 2) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the slag on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 3) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy molten liquid.

[0069] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0070] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0071] Comparative Example 5 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6% and a B / Ti molar ratio of 2.2, under the condition of Sc addition of 1%. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-10Sc master alloy is 10%; 4) The mass fraction of Al-Si alloy is 36.64%.

[0072] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0073] Step (3) Shaping The molten aluminum alloy is poured into a barrel and indirectly extruded and cast. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0074] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0075] Comparative Example 6 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6%, a B / Ti molar ratio of 2.2, and a Sc element content of 0.1%, without ultrasonic treatment. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 45.64%.

[0076] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy, Al-10Sc master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. 2) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the slag on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 3) Raise the furnace temperature to the pouring temperature and maintain it at 730℃.

[0077] Step (3) Shaping Molten metal is poured into a barrel for indirect extrusion casting. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0078] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0079] Comparative Example 7 This comparative example provides an extrusion casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6%, a B / Ti molar ratio of 2.2, and a Sc element content of 0.1%, without the application of rotary blowing treatment. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 45.64%.

[0080] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy, and Al-Si alloy according to their mass fractions and place them together in a melting furnace. Heat the furnace to 750℃ and hold until completely melted. Then lower the melt temperature to 680℃. 2) Apply ultrasonic vibration treatment to the melt for 15 minutes. The melt temperature is 680℃. 3) Add the Al-10Sc master alloy to the melt and hold until completely melted. The melt temperature is 680℃. 4) Apply ultrasonic vibration treatment to the melt for 15 minutes. 5) Raise the furnace temperature to the casting temperature and hold. The casting temperature is 730℃.

[0081] Step (3) Shaping Molten metal is poured into a barrel for indirect extrusion casting. The casting pressure is 140 MPa, the mold temperature is 250℃, the injection speed is 4 mm / s, and the injection time is 30 s.

[0082] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0083] Comparative Example 8 This comparative example provides a casting method for preparing TiB2 particle-reinforced aluminum matrix composites with a TiB2 mass fraction of 6%, a B / Ti molar ratio of 2.2, and a Sc element content of 0.1%, without using extrusion casting. The specific steps are as follows: Step (1) Raw material preparation and proportioning 1) The mass fraction of Al-15Ti master alloy is 27.43%; 2) The mass fraction of Al-8B master alloy is 25.93%; 3) The mass fraction of Al-10Sc master alloy is 1%; 4) The mass fraction of Al-Si alloy is 45.64%.

[0084] Step (2) Smelting 1) Weigh the Al-15Ti master alloy, Al-8B master alloy and Al-Si alloy according to the mass fraction and put them into the melting furnace. Heat the furnace to 750℃ and hold it until completely melted. Then lower the melt temperature to 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. The melt temperature is 680℃. This is called the first melt. 2) Add the Al-10Sc master alloy to the first molten liquid and heat it until it is completely melted. The melt temperature is 680℃. Apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 15min. This is called the second molten liquid. 3) High-purity argon gas was introduced at a rate of 5 L / min to perform rotary blowing treatment on the melt, and then the scum on the surface of the melt was removed. The treatment time was 25 min and the rotation speed was 150 r / min. 4) Raise the furnace temperature to the pouring temperature and hold it at 730℃; apply ultrasonic vibration (frequency 20kHz, power 2kw) to the melt for 5 minutes, and record it as aluminum alloy melt.

[0085] Step (3) Shaping The molten aluminum alloy is poured into a mold and gravity-cast into shape.

[0086] The as-cast mechanical properties of the aluminum alloy components are shown in Table 1.

[0087] Table 1. Comparison of the as-cast mechanical properties of test bars prepared in the Examples and Comparative Examples

[0088] The advantages of this invention can be clearly seen through the comparison in Table 1.

[0089] The results of the embodiments show that, using the content of the present invention, in-situ controlled generation of TiB2 particles achieves an equiaxed state while exhibiting good dispersion uniformity. Further optimization of the composite material microstructure using extrusion casting technology results in a final material with excellent as-cast strength and toughness, as well as performance stability. Figure 1 Compared with the traditional method of directly introducing TiB2 particles using Al-5Ti-B master alloy (Comparative Example 1), the overall performance of the composite material is significantly improved, which clearly demonstrates the advanced nature of the technical method of this invention.

[0090] For conditions exceeding the scope of the claims of this invention, excessively low (Comparative Example 2) or excessively high (Comparative Example 3) B / Ti molar ratios will cause a significant reduction in the overall performance of the composite material, especially a substantial decrease in elongation. Furthermore, excessively low Sc content (Comparative Example 4) will have a slight impact on the tensile strength of the composite material. This is mainly because conditions exceeding the scope of the claims cannot effectively control the equiaxed geometry of the in-situ TiB2 particles and achieve optimal results. Figure 2 Excessive Sc content (Comparative Example 5) does not significantly improve or reduce the performance of composite materials, but it does increase material costs.

[0091] Comparative Example 6, due to the lack of ultrasonic dispersion treatment of the melt, will cause in-situ agglomeration of TiB2 particles. Comparative Example 7, due to the lack of rotary blowing treatment, will introduce a higher content of gas and oxide inclusions into the melt. These will seriously affect the melt quality and thus cause a significant reduction in the performance of the composite material.

[0092] For the in-situ equiaxed TiB2 particle-reinforced aluminum matrix composite material involved in this invention, its as-cast mechanical properties are significantly reduced under gravity casting conditions (Comparative Example 8), especially the elongation is greatly reduced. Due to the introduction of TiB2 particles, the melt fluidity is weakened, the casting performance is worsened, and it is easier to introduce structural defects under gravity casting conditions. In contrast, squeeze casting technology completes the solidification process under pressure, improves the feeding ability and eliminates defects, better adapts to the melt characteristics of the composite material, and refines the microstructure grains to ensure that the composite material obtains good strength and toughness mechanical properties.

[0093] In summary, based on the in-situ reaction method of intermediate alloys, by precisely controlling the molar ratio of key reactant element B / Ti and using an appropriate amount of microalloying element Sc, the near-equiaxed geometry of in-situ TiB2 particles in the melt can be effectively controlled. This is further combined with online ultrasonic treatment to ensure the effective dispersion and uniform distribution of reinforcing phase particles, and argon rotary blowing to reduce gas content and oxide inclusions, resulting in an ideal melt. Finally, the extrusion casting process is used to ensure that the ideal as-cast structure is obtained through pressure-assisted solidification. In the product, this results in excellent comprehensive strength and toughness with significantly improved tensile strength and elongation.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a TiB2 particle-reinforced aluminum matrix composite material, characterized by, The method comprises the following steps: (1) melting Al-15Ti intermediate alloy, Al-8B intermediate alloy and industrial aluminum alloy together, and performing ultrasonic treatment after melting to obtain a first melting liquid; (2) adding Al-10Sc intermediate alloy into the first melting liquid for melting, and performing ultrasonic treatment after melting to obtain a second melting liquid; (3) performing rotary blowing treatment on the second melting liquid by blowing argon, and then performing ultrasonic treatment to obtain an aluminum alloy melting liquid; (4) performing extrusion casting on the aluminum alloy melting liquid to obtain a TiB2 particle reinforced aluminum matrix composite material.

2. The production method according to claim 1, characterized by, The Al-15Ti intermediate alloy and the Al-8B intermediate alloy are prepared according to a B / Ti molar ratio; the B / Ti molar ratio is 2.2-3; and the TiB2 particles prepared from the Al-15Ti intermediate alloy and the Al-8B intermediate alloy have a mass fraction of 5-10% in the aluminum matrix composite material.

3. The preparation method according to claim 1, characterized in that, The Al-10Sc intermediate alloy is prepared according to a designed Sc element addition amount; the Sc accounts for 0.1-0.5% of the mass of the TiB2 particle reinforced aluminum matrix composite material.

4. The method of claim 1, wherein, The industrial aluminum alloy comprises an Al-Si alloy; and the feeding amount of the industrial aluminum alloy accounts for the remaining amount except the Al-15Ti intermediate alloy, the Al-8B intermediate alloy and the Al-10Sc intermediate alloy in the total mass of the final TiB2 particle reinforced aluminum matrix composite material.

5. The preparation method according to claim 1, characterized in that, In step (1), the melting temperature is 750 DEG C, the ultrasonic frequency is 20 kHz, the power is 2 kw, and the time is 10-15 min.

6. The method of claim 1, wherein, In step (2), the temperature of the first melting liquid is 680-690 DEG C, the ultrasonic frequency is 20 kHz, the power is 2 kw, and the time is 10-15 min.

7. The preparation method according to claim 1, characterized in that, In step (3), the argon blowing speed is 5-10 L / min, the rotary blowing treatment rotating speed is 150-160 r / min, the temperature is 680-690 DEG C, the time is 20-25 min, the ultrasonic frequency is 20 kHz, the power is 2 kw, and the time is 3-5 min.

8. The method of claim 1, wherein, In step (4), the temperature of the aluminum alloy melting liquid is 725-730 DEG C, the extrusion casting pressure is 120-140 MPa, the mold temperature is 230-250 DEG C, the injection low speed is 4-5 mm / s, and the injection time is 20-30 s.

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