阅读说明：本技术 一种铝合金汽车排气管材及其制备方法 (Aluminum alloy automobile exhaust pipe and preparation method thereof ) 是由 王思记 丁恒 陈静莹 江辉宏 于 2020-07-01 设计创作，主要内容包括：本发明涉及一种铝合金汽车排气管材及其制备方法,属于金属管材制备技术领域。本发明首先以稻壳为原料,将其预处理并碳化,制备得到碳化硅纤维,将碳化硅纤维和硅酸钠溶液混合,并加入盐酸反应生成原硅酸沉淀附着在碳化硅纤维表面,之后再在高温条件下,使得原硅酸沉淀水解产生二氧化氧化硅附着在碳化硅纤维表面,最终制得改性碳化硅纤维,最后将改性碳化硅纤维和铝合金溶体共混压制得到铝合金汽车排气管材,得到本发明使用了改性碳化硅纤维,本发明制得的铝合金汽车排气管材的抗弯折强度高,具有广阔的应用前景。(The invention relates to an aluminum alloy automobile exhaust pipe and a preparation method thereof, and belongs to the technical field of metal pipe preparation. The method comprises the steps of firstly pretreating and carbonizing rice hulls serving as raw materials to prepare silicon carbide fibers, mixing the silicon carbide fibers with a sodium silicate solution, adding hydrochloric acid to react to generate orthosilicic acid precipitates to be attached to the surfaces of the silicon carbide fibers, then hydrolyzing the orthosilicic acid precipitates to generate silicon dioxide to be attached to the surfaces of the silicon carbide fibers at high temperature, finally preparing modified silicon carbide fibers, and finally blending and pressing the modified silicon carbide fibers and an aluminum alloy solution to obtain the aluminum alloy automobile exhaust pipe.)

1. The utility model provides an aluminum alloy automobile exhaust tubular product, includes modified silicon carbide fibre and aluminum alloy fuse-element, its characterized in that:

the modified silicon carbide fiber is prepared by reacting rice hull-based silicon carbide, a sodium silicate solution and hydrochloric acid;

the rice hull-based silicon carbide is prepared from rice hulls;

the aluminum alloy melt is made of aluminum chloride, aluminum ingots, titanium dioxide and nickel.

2. The preparation method of the aluminum alloy automobile exhaust pipe is characterized by comprising the following specific preparation steps:

(1) mixing rice hulls with deionized water, ultrasonically cleaning and drying to obtain pretreated rice hulls;

(2) carbonizing the pretreated rice hulls to obtain rice hull-based silicon carbide fibers;

(3) mixing the rice hull-based silicon carbide and the sodium silicate solution, adjusting the pH value with hydrochloric acid, filtering to obtain filter residue, reacting, and filtering to obtain reaction filter residue, namely modified silicon carbide fiber;

(4) heating the resistance furnace, adding aluminum chloride, continuously adding aluminum ingots, adding titanium dioxide and nickel after the aluminum ingots are melted into molten aluminum, and performing heat preservation melting to obtain an aluminum alloy melt;

(5) vertically inserting the modified silicon carbide fiber into an exhaust pipe mold, pouring an aluminum alloy melt into the exhaust pipe mold under the protection of argon, die-casting, annealing, and demolding to obtain the aluminum alloy automobile exhaust pipe.

3. The preparation method of the aluminum alloy automobile exhaust pipe material according to claim 2, which is characterized by comprising the following specific preparation steps:

(1) mixing rice hulls and deionized water, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning, putting the mixture into an oven after cleaning, and drying to obtain pretreated rice hulls;

(2) putting the pretreated rice hulls into a carbonization furnace, heating and heating for heat treatment under the protection of carbon dioxide, heating again, preserving heat and carbonizing, and discharging after carbonization to obtain rice hull-based silicon carbide fibers;

(3) mixing the obtained rice hull-based silicon carbide and sodium silicate solution, adjusting the pH value with hydrochloric acid, continuously stirring, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting, and filtering to obtain reaction filter residue, thus obtaining the modified silicon carbide fiber;

(4) heating the resistance furnace, adding aluminum chloride into the resistance furnace, preserving heat, continuously adding an aluminum ingot, heating, preserving heat, adding titanium dioxide and nickel into the aluminum liquid after the aluminum ingot is melted into aluminum liquid, preserving heat and melting to obtain an aluminum alloy melt;

(5) according to parts by weight, vertically inserting modified silicon carbide fibers into a semi-open type exhaust pipe mold, putting the exhaust pipe mold into a drying oven for heating, preheating, taking out the exhaust pipe mold, pouring an aluminum alloy melt into the exhaust pipe mold under the protection of argon, covering a pressure head of the mold, putting the mold into a press for die casting, controlling the die casting pressure, after die casting, putting the mold into water for annealing until the mold is cooled to normal temperature, and demolding to obtain the aluminum alloy automobile exhaust pipe.

4. The preparation method of the aluminum alloy automobile exhaust pipe material according to the claim 2 or 3, which is characterized by comprising the following specific preparation steps:

(1) mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 1-3 times at a power of 300-400W, putting the mixture into an oven after cleaning, and drying at 105-110 ℃ to obtain pretreated rice hulls;

(2) putting the pretreated rice hulls into a carbonization furnace, heating to 300-350 ℃ under the protection of carbon dioxide, carrying out heat treatment for 10-20 min, heating to 1900-2000 ℃, carrying out heat preservation carbonization for 9-10 h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers;

(3) mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 5-6 by using hydrochloric acid, continuously stirring for 1-2 h, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 150-200 ℃ for 30-40 min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber;

(4) heating a resistance furnace to 500-520 ℃ according to parts by weight, adding 4-5 parts of aluminum chloride into the resistance furnace, preserving heat for 10-12 min, continuously adding 80-90 parts of aluminum ingots, heating to 770-800 ℃, preserving heat for 3-4 h, adding 10-15 parts of titanium dioxide and 5-10 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, preserving heat and melting to obtain an aluminum alloy melt;

(5) according to the weight parts, 20-30 parts of modified silicon carbide fiber are vertically inserted into a semi-open type exhaust pipe mold, the exhaust pipe mold is placed into an oven to be heated to 120-150 ℃, preheated for 30-35 min, the exhaust pipe mold is taken out, an aluminum alloy melt with the temperature of 700-720 ℃ is poured into the exhaust pipe mold under the protection of argon, a pressure head of the mold is covered, the mold is placed into a press machine to be subjected to pressure casting, the pressure casting pressure is controlled to be 0.3-0.4 MPa, after 20-25 min of pressure casting, the mold is placed into water with the temperature of 20-25 ℃ to be annealed until the mold is cooled to the normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after demolding.

Technical Field

The invention relates to an aluminum alloy automobile exhaust pipe and a preparation method thereof, and belongs to the technical field of metal pipe preparation.

Background

At present, the exhaust pipe is installed between the exhaust manifold of the engine and the muffler to make the whole exhaust system in flexible connection for the purpose of damping vibration and reducing noise, facilitating installation and prolonging the service life of the exhaust muffler system. The exhaust pipe is mainly used for light vehicles, mini vehicles and passenger vehicles, and motorcycles, and is structurally characterized in that a double-layer corrugated pipe is externally coated with a steel wire mesh sleeve, and clamping rings are externally coated on straight side sections at two ends of the double-layer corrugated pipe, so that the exhaust pipe has a better noise elimination effect, and an expansion joint or a mesh sleeve can be matched in the corrugated pipe. The main material of the exhaust pipe is stainless steel, and the cutting ferrule and the connecting pipe can be made of stainless steel or aluminized steel.

With the continuous and rapid increase of the economy of China, the living standard of people is higher and higher, and particularly automobiles become a new consumption hotspot for residents in the current society. At present, energy conservation and emission reduction become competitive edge tools in the automobile industry, so that an exhaust system of an automobile is more important, and a small amount of Mn, Nb and other elements are added into the iron alloy, so that the iron alloy has good deep drawability, and other properties of the exhaust system can be improved. The automobile material has wide development space today in the direction of light weight, energy conservation and environmental protection; the exhaust pipe of an automobile is located at the rear end of the automobile, and is subjected to a high working environment temperature, and has high requirements for heat resistance, impact resistance, and corrosion resistance, and these members are manufactured from a steel sheet by means of press working, and therefore, a base steel sheet is required to have press formability. On the other hand, the ambient temperature for use is also increasing year by year, and it is necessary to increase the amount of alloy elements such as Cr, Mo, and Nb to improve the high-temperature strength, oxidation resistance, thermal fatigue characteristics, and the like. The aluminum alloy material for the automobile exhaust pipe has the defect of poor bending resistance at present, so that the invention of the automobile exhaust pipe made of the aluminum alloy with good bending resistance has positive significance in the technical field of aluminum alloy preparation.

In view of the above-mentioned drawbacks, the present designer is actively making research and innovation to create an aluminum alloy automobile exhaust pipe and a manufacturing method thereof, so that the aluminum alloy automobile exhaust pipe has industrial utility value.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide an aluminum alloy automobile exhaust pipe and a preparation method thereof. The invention relates to an aluminum alloy automobile exhaust pipe, which comprises modified silicon carbide fiber and an aluminum alloy melt,

the modified silicon carbide fiber is prepared by reacting rice hull-based silicon carbide, a sodium silicate solution and hydrochloric acid;

the rice hull-based silicon carbide is prepared from rice hulls;

the aluminum alloy melt is made of aluminum chloride, aluminum ingots, titanium dioxide and nickel.

A preparation method of an aluminum alloy automobile exhaust pipe comprises the following specific preparation steps:

(1) mixing rice hulls with deionized water, ultrasonically cleaning and drying to obtain pretreated rice hulls;

(2) carbonizing the pretreated rice hulls to obtain rice hull-based silicon carbide fibers;

(3) mixing the rice hull-based silicon carbide and the sodium silicate solution, adjusting the pH value with hydrochloric acid, filtering to obtain filter residue, reacting, and filtering to obtain reaction filter residue, namely modified silicon carbide fiber;

(4) heating the resistance furnace, adding aluminum chloride, continuously adding aluminum ingots, adding titanium dioxide and nickel after the aluminum ingots are melted into molten aluminum, and performing heat preservation melting to obtain an aluminum alloy melt;

(5) vertically inserting the modified silicon carbide fiber into an exhaust pipe mold, pouring an aluminum alloy melt into the exhaust pipe mold under the protection of argon, die-casting, annealing, and demolding to obtain the aluminum alloy automobile exhaust pipe.

Further, the preparation method comprises the following specific steps:

(1) mixing rice hulls and deionized water, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning, putting the mixture into an oven after cleaning, and drying to obtain pretreated rice hulls;

(2) putting the pretreated rice hulls into a carbonization furnace, heating and heating for heat treatment under the protection of carbon dioxide, heating again, preserving heat and carbonizing, and discharging after carbonization to obtain rice hull-based silicon carbide fibers;

(3) mixing the obtained rice hull-based silicon carbide and sodium silicate solution, adjusting the pH value with hydrochloric acid, continuously stirring, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting, and filtering to obtain reaction filter residue, thus obtaining the modified silicon carbide fiber;

(4) heating the resistance furnace, adding aluminum chloride into the resistance furnace, preserving heat, continuously adding an aluminum ingot, heating, preserving heat, adding titanium dioxide and nickel into the aluminum liquid after the aluminum ingot is melted into aluminum liquid, preserving heat and melting to obtain an aluminum alloy melt;

(5) according to parts by weight, vertically inserting modified silicon carbide fibers into a semi-open type exhaust pipe mold, putting the exhaust pipe mold into a drying oven for heating, preheating, taking out the exhaust pipe mold, pouring an aluminum alloy melt into the exhaust pipe mold under the protection of argon, covering a pressure head of the mold, putting the mold into a press for die casting, controlling the die casting pressure, after die casting, putting the mold into water for annealing until the mold is cooled to normal temperature, and demolding to obtain the aluminum alloy automobile exhaust pipe.

Further, the preparation method comprises the following specific steps:

(1) mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 1-3 times at a power of 300-400W, putting the mixture into an oven after cleaning, and drying at 105-110 ℃ to obtain pretreated rice hulls;

(2) putting the pretreated rice hulls into a carbonization furnace, heating to 300-350 ℃ under the protection of carbon dioxide, carrying out heat treatment for 10-20 min, heating to 1900-2000 ℃, carrying out heat preservation carbonization for 9-10 h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers;

(3) mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 5-6 by using hydrochloric acid, continuously stirring for 1-2 h, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 150-200 ℃ for 30-40 min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber;

(4) heating a resistance furnace to 500-520 ℃ according to parts by weight, adding 4-5 parts of aluminum chloride into the resistance furnace, preserving heat for 10-12 min, continuously adding 80-90 parts of aluminum ingots, heating to 770-800 ℃, preserving heat for 3-4 h, adding 10-15 parts of titanium dioxide and 5-10 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, preserving heat and melting to obtain an aluminum alloy melt;

(5) according to the weight parts, 20-30 parts of modified silicon carbide fiber are vertically inserted into a semi-open type exhaust pipe mold, the exhaust pipe mold is placed into an oven to be heated to 120-150 ℃, preheated for 30-35 min, the exhaust pipe mold is taken out, an aluminum alloy melt with the temperature of 700-720 ℃ is poured into the exhaust pipe mold under the protection of argon, a pressure head of the mold is covered, the mold is placed into a press machine to be subjected to pressure casting, the pressure casting pressure is controlled to be 0.3-0.4 MPa, after 20-25 min of pressure casting, the mold is placed into water with the temperature of 20-25 ℃ to be annealed until the mold is cooled to the normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after demolding.

By the scheme, the invention at least has the following advantages:

the invention firstly takes rice hulls as raw materials, the rice hulls are pretreated and carbonized to prepare silicon carbide fiber, the silicon carbide fiber and a sodium silicate solution are mixed, hydrochloric acid is added to react to generate orthosilicic acid precipitate which is attached to the surface of the silicon carbide fiber, then under the high temperature condition, the orthosilicic acid precipitate is hydrolyzed to generate silicon dioxide which is attached to the surface of the silicon carbide fiber, modified silicon carbide fiber is finally prepared, and finally the modified silicon carbide fiber and an aluminum alloy solution are mixed and pressed to obtain the aluminum alloy automobile exhaust pipe, the modified silicon carbide fiber is used, after the modified silicon carbide fiber is poured by aluminum liquid, the silicon dioxide and the aluminum on the surface of the modified silicon carbide fiber react at high temperature, the reaction product is aluminum oxide, the continuous generation of the aluminum oxide and the continuous reaction of other elements in the form of simple substance and the aluminum liquid enter the melt or exist in the form of solid solution in the aluminum oxide in the interfacial reaction process, the alumina phase and the aluminum matrix are well combined to form a strong physical combination or coherent interface, the interface reaction product alumina exists on the surface layer of the fiber in a thin layer form and is directly contacted with the matrix metal aluminum, the interface is smooth and straight, so that the load can be smoothly transferred to the fiber when the aluminum alloy material is bent, and in addition, a silicon dioxide coating is introduced on the surface of the basalt fiber, so that on one hand, the silicon dioxide coating on the surface can be sacrificed to achieve the purpose of protecting the fiber, and the fiber performance damage caused by a large amount of participation of the silicon dioxide coating in the interface reaction is avoided; on the other hand, the interface reaction system can be simplified, and the generation of uncontrollable and non-uniformly distributed brittle phases generated by the reaction of the aluminum matrix and other fiber components is reduced, so that the bending resistance of the aluminum alloy is improved.

The foregoing is a summary of the present invention, and in order to provide a clear understanding of the technical means of the present invention and to be implemented in accordance with the present specification, the following is a detailed description of the preferred embodiments of the present invention.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 1-3 times at a power of 300-400W, putting the mixture into an oven after cleaning, and drying at 105-110 ℃ to obtain pretreated rice hulls; putting the pretreated rice hulls into a carbonization furnace, heating to 300-350 ℃ under the protection of carbon dioxide, carrying out heat treatment for 10-20 min, heating to 1900-2000 ℃, carrying out heat preservation carbonization for 9-10 h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers; mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 5-6 by using hydrochloric acid, continuously stirring for 1-2 h, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 150-200 ℃ for 30-40 min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber; heating a resistance furnace to 500-520 ℃ according to parts by weight, adding 4-5 parts of aluminum chloride into the resistance furnace, preserving heat for 10-12 min, continuously adding 80-90 parts of aluminum ingots, heating to 770-800 ℃, preserving heat for 3-4 h, adding 10-15 parts of titanium dioxide and 5-10 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, preserving heat and melting to obtain an aluminum alloy melt; according to the weight parts, 20-30 parts of modified silicon carbide fiber are vertically inserted into a semi-open type exhaust pipe mold, the exhaust pipe mold is placed into an oven to be heated to 120-150 ℃, preheated for 30-35 min, the exhaust pipe mold is taken out, an aluminum alloy melt with the temperature of 700-720 ℃ is poured into the exhaust pipe mold under the protection of argon, a pressure head of the mold is covered, the mold is placed into a press machine to be subjected to pressure casting, the pressure casting pressure is controlled to be 0.3-0.4 MPa, after 20-25 min of pressure casting, the mold is placed into water with the temperature of 20-25 ℃ to be annealed until the mold is cooled to the normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after demolding.

Example 1

Mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 1 time at a power of 300W, putting the mixture into an oven after cleaning, and drying at 105 ℃ to obtain pretreated rice hulls; putting the pretreated rice hulls into a carbonization furnace, heating to 300 ℃ under the protection of carbon dioxide for heat treatment for 10min, heating to 1900 ℃, preserving heat for carbonization for 9h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers; mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 5 by using hydrochloric acid, continuously stirring for 1h, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 150 ℃ for 30min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber; heating a resistance furnace to 500 ℃ according to parts by weight, adding 4 parts of aluminum chloride into the resistance furnace, preserving heat for 10min, continuously adding 80 parts of aluminum ingots, heating to 770 ℃, preserving heat for 3h, adding 10 parts of titanium dioxide and 5 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, and preserving heat for melting to obtain an aluminum alloy melt; according to the weight parts, 20 parts of modified silicon carbide fiber are vertically inserted into a semi-open type exhaust pipe mold, the exhaust pipe mold is placed into an oven to be heated to 120 ℃, the exhaust pipe mold is preheated for 30min, the exhaust pipe mold is taken out, aluminum alloy melt with the temperature of 700 ℃ is poured into the exhaust pipe mold under the protection of argon, a pressure head of the mold is covered, the mold is placed into a press machine to be subjected to die casting, the die casting pressure is controlled to be 0.3MPa, after 20min of die casting, the mold is placed into water with the temperature of 20 ℃ to be annealed until the mold is cooled to normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after demolding.

Example 2

Mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 2 times at a power of 350W, putting the mixture into an oven after cleaning, and drying at 108 ℃ to obtain pretreated rice hulls; putting the pretreated rice hulls into a carbonization furnace, heating to 330 ℃ under the protection of carbon dioxide, carrying out heat treatment for 15min, heating to 1950 ℃, carrying out heat preservation carbonization treatment for 9h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers; mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 6 by using hydrochloric acid, continuously stirring for 2 hours, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 180 ℃ for 35min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber; heating a resistance furnace to 510 ℃ according to parts by weight, adding 4 parts of aluminum chloride into the resistance furnace, preserving heat for 11min, continuously adding 85 parts of aluminum ingots, heating to 785 ℃, preserving heat for 4h, adding 13 parts of titanium dioxide and 8 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, and preserving heat for melting to obtain an aluminum alloy melt; according to the weight parts, 25 parts of modified silicon carbide fiber is vertically inserted into a semi-open type exhaust pipe mold, the exhaust pipe mold is placed into an oven to be heated to 140 ℃, the preheating is carried out for 33min, the exhaust pipe mold is taken out, an aluminum alloy melt with the temperature of 710 ℃ is poured into the exhaust pipe mold under the protection of argon, a pressure head of the mold is covered, the mold is placed into a press machine to be subjected to die casting, the die casting pressure is controlled to be 0.4MPa, after the die casting is carried out for 23min, the mold is placed into water with the temperature of 23 ℃ to be annealed until the mold is cooled to normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after the.

Example 3

Mixing rice hulls and deionized water according to a mass ratio of 1:7, pouring the mixture into an ultrasonic cleaning instrument, ultrasonically cleaning for 3 times at a power of 400W, putting the mixture into an oven after cleaning, and drying at 110 ℃ to obtain pretreated rice hulls; putting the pretreated rice hulls into a carbonization furnace, heating to 350 ℃ under the protection of carbon dioxide for heat treatment for 20min, heating to 2000 ℃, preserving heat for carbonization for 10h, and discharging after carbonization to obtain rice hull-based silicon carbide fibers; mixing the obtained rice hull-based silicon carbide and a sodium silicate solution with the mass fraction of 30% according to the mass ratio of 1:10, adjusting the pH to 6 by using hydrochloric acid, continuously stirring for 2 hours, filtering to obtain filter residue, putting the filter residue into a high-temperature reaction kettle, reacting at 200 ℃ for 40min, and filtering to obtain reaction filter residue, namely obtaining modified silicon carbide fiber; heating a resistance furnace to 520 ℃ according to parts by weight, adding 5 parts of aluminum chloride into the resistance furnace, preserving heat for 12min, continuously adding 90 parts of aluminum ingots, heating to 800 ℃, preserving heat for 4h, adding 15 parts of titanium dioxide and 10 parts of nickel into the aluminum liquid after the aluminum ingots are melted into aluminum liquid, and preserving heat for melting to obtain an aluminum alloy melt; according to the weight parts, 30 parts of modified silicon carbide fiber is vertically inserted into a semi-open type exhaust pipe die, the exhaust pipe die is placed into an oven to be heated to 150 ℃, the exhaust pipe die is preheated for 35min, the exhaust pipe die is taken out, an aluminum alloy melt with the temperature of 720 ℃ is poured into the exhaust pipe die under the protection of argon, a pressure head of the die is covered, the die is placed into a press machine to be die-cast, the die-casting pressure is controlled to be 0.4MPa, after 25min of die-casting, the die is placed into 25 ℃ water to be annealed until the die is cooled to normal temperature, and the aluminum alloy automobile exhaust pipe is obtained after die-casting.

Comparative example

The aluminum alloy automobile exhaust pipe material prepared by the invention and the aluminum alloy automobile exhaust pipe material in the comparative example are subjected to performance detection by taking the aluminum alloy material for the automobile exhaust pipe produced by Guangdong company as the comparative example, and the detection results are shown in Table 1:

1. the test method comprises the following steps:

the bending strength test adopts an aluminum alloy tensile and bending resistance testing machine for detection.

Remarking: a three-point bending fixture is adopted, and the actual test speed is 1mm/mim with a pressure head of R5.

TABLE 1

According to the data, the aluminum alloy automobile exhaust pipe prepared by the method is high in bending strength and has a wide application prospect.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.