CN102912264A - Preparation method for coating ceramic phase reinforcement/aluminum-based composite material through nanometer bismuth oxide - Google Patents

Abstract

The invention discloses a preparation method of nano bismuth oxide coated ceramic phase reinforcement/aluminum matrix composite material, which relates to a preparation method of aluminum matrix composite material. It aims to solve the problems of poor wettability between the ceramic phase reinforcement and the aluminum matrix, poor room temperature damping performance and high molding temperature of the material. Method: The ceramic reinforcement is mixed with distilled water to obtain a mixture; solution A and ammonia solution are added to the mixture; the reinforcement is kept warm in a hydrothermal kettle, and after cooling, a preform is prepared and sintered; the preform is heated, and then poured into molten aluminum or Aluminum alloy, demoulding is completed after pressurization. The present invention uses the method of hydrothermal synthesis to coat the surface of the ceramic reinforcement, which not only can obtain a nano-sized coating, but also greatly improves the uniformity of the coating distribution, and the introduction of the coating not only effectively prevents the Wettability, and can improve the damping performance of the composite material and reduce the molding temperature, improve the interface bonding strength, and the inorganic salt raw materials for preparing the coating are cheap, and the coating process is simple.

Description

Preparation method of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite

technical field

The invention relates to a preparation method of an aluminum-based composite material.

Background technique

Metal matrix composites not only have high strength and modulus, but also have good mechanical damping properties, and are currently one of the most promising structural-functional damping materials. If damping is the goal, metal matrix composites may not be the best choice, but its combination of high modulus and high damping is unmatched by other materials. In particular, the high degree of designability of the performance of composite materials makes people expect to use this feature to make composite materials with excellent mechanical properties and damping properties be used in aerospace, precision instruments and other fields. In the study of metal matrix composites, the reinforcement/matrix interface has always been the focus of attention, because the state of the interface region not only strongly affects the mechanical properties of the composite material but also has a significant effect on its damping properties; The poor wettability between the phase reinforcement and the aluminum matrix leads to a decrease in the mechanical properties of the material, poor room temperature damping performance and high molding temperature of the material, which has become a "bottleneck" restricting its production and application.

Contents of the invention

The purpose of the present invention is to provide nano-bismuth oxide coated ceramic phase reinforcement/aluminum substrate in order to solve the problems of poor wettability between the existing ceramic phase reinforcement and the aluminum matrix, poor room temperature damping performance and high molding temperature of the material. Methods of preparation of composite materials.

The preparation method of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite material is realized according to the following steps:

1. Mix the ceramic reinforcement with distilled water according to the mass ratio of 1:40-80, and ultrasonically disperse after stirring to obtain a mixture;

2. Add solution A and ammonia solution to the mixture obtained in step 1 at the same time in the form of atomization and stir. During the addition process, the pH value of the system is controlled at 6-12;

3. After the addition, let it stand for 1-5 hours, pour out the clarified water in the container, pour the reinforcement into a hydrothermal kettle, keep it warm at 100-300°C for 1-24 hours, and pour the reinforcement into the mold after natural cooling Intermediate pressing to obtain a prefabricated part of the reinforcement and demoulding;

4. Heat the prefabricated part of the reinforcement at 400-1100°C for 30-120 minutes, then put it into the mold and heat it to 450-550°C, then pour molten aluminum or aluminum alloy into the mold and pressurize it to 80-200MPa , demoulding after holding the pressure for 15-30 minutes, that is, the preparation of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite material is completed;

Wherein in step 2, solution A is the nitric acid solution of bismuth nitrate or the hydrochloric acid solution of bismuth chloride; The concentration of bismuth chloride in the hydrochloric acid solution of bismuth is 0.00001～0.2mol/L, the concentration of hydrochloric acid is 0.00001～1mol/L; the concentration of ammonia solution is 0.001～1mol/L;

In the second step, the mass ratio of the Bi element to the ceramic reinforcement is 1:5-80.

The present invention uses the method of hydrothermal synthesis to coat the surface of the ceramic reinforcement, which not only can obtain a nano-sized coating, but also greatly improves the uniformity of the coating distribution, and the introduction of the coating not only effectively prevents the Wettability, and can improve the damping performance of the composite material and reduce the molding temperature, improve the interfacial bonding strength, and the inorganic salt raw material for preparing the coating is cheap, and the coating process is simple; the reinforcement (Bi element and ceramic reinforcement prepared by the present invention The tensile strength of the composite material with a mass ratio of 1:40) and a volume fraction of 20% can reach 350MPa, which is more than 15% higher than the existing composite material tensile strength (250-300MPa), and the room temperature damping performance is more than doubled , High temperature molding temperature can be reduced by nearly 200 ℃.

Description of drawings

Fig. 1 is a scanning electron microscope image of the surface of the sintered reinforcement in step 4 of the embodiment of the present invention.

Detailed ways

The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

Specific embodiment 1: The preparation method of the nano-bismuth oxide-coated ceramic phase reinforcement/aluminum-based composite material in this embodiment is realized according to the following steps:

1. Mix the ceramic reinforcement with distilled water according to the mass ratio of 1:40-80, and ultrasonically disperse after stirring to obtain a mixture;

2. Add solution A and ammonia solution to the mixture obtained in step 1 at the same time in the form of atomization and stir. During the addition process, the pH value of the system is controlled at 6-12;

3. After the addition, let it stand for 1-5 hours, pour out the clarified water in the container, pour the reinforcement into a hydrothermal kettle, keep it warm at 100-300°C for 1-24 hours, and pour the reinforcement into the mold after natural cooling Intermediate pressing to obtain a prefabricated part of the reinforcement and demoulding;

4. Heat the prefabricated part of the reinforcement at 400-1100°C for 30-120 minutes, then put it into the mold and heat it to 450-550°C, then pour molten aluminum or aluminum alloy into the mold and pressurize it to 80-200MPa , demoulding after holding the pressure for 15-30 minutes, that is, the preparation of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite material is completed;

Wherein in step 2, solution A is the nitric acid solution of bismuth nitrate or the hydrochloric acid solution of bismuth chloride; The concentration of bismuth chloride in the hydrochloric acid solution of bismuth is 0.00001～0.2mol/L, the concentration of hydrochloric acid is 0.00001～1mol/L; the concentration of ammonia solution is 0.001～1mol/L;

In the second step, the mass ratio of the Bi element to the ceramic reinforcement is 1:5-80.

In step 2 of the present embodiment, the ammonia solution is just to adjust the pH value, which is sufficient.

Embodiment 2: This embodiment differs from Embodiment 1 in that in Step 1, the ceramic reinforcement is mixed with distilled water at a mass ratio of 1:40. Other steps and parameters are the same as those in Embodiment 1.

Embodiment 3: The difference between this embodiment and Embodiment 1 is that in Step 1, the ceramic reinforcement is mixed with distilled water at a mass ratio of 1:80. Other steps and parameters are the same as those in Embodiment 1.

Embodiment 4: This embodiment differs from Embodiment 1 in that in Step 1, the ceramic reinforcement is mixed with distilled water at a mass ratio of 1:60. Other steps and parameters are the same as those in Embodiment 1.

Embodiment 5: The difference between this embodiment and one of Embodiments 1 to 4 is that the pH value of the system is controlled at 8 during the addition process in step 2. Other steps and parameters are the same as in one of the specific embodiments 1 to 4.

Specific embodiment six: the difference between this embodiment and one of the specific embodiments one to five is that in step 3, after the addition is completed, let it stand for 3 hours, and after pouring out the clarified water in the container, pour the reinforcing body into the hydrothermal kettle, and set the temperature at 200 Incubate at ℃ for 12h. Other steps and parameters are the same as one of the specific embodiments 1 to 5.

Embodiment 7: The difference between this embodiment and one of Embodiments 1 to 6 is that in step 4, the prefabricated part of the reinforcing body is kept at 500°C for 60 minutes, then put into a mold and heated to 520°C, and then the molten aluminum Or pour aluminum alloy into the mold and pressurize to 100MPa, keep the pressure for 20min and then demould. Other steps and parameters are the same as one of the specific embodiments 1 to 6.

Example

The preparation method of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite material is realized according to the following steps:

1. Mix the ceramic reinforcement with distilled water according to the mass ratio of 1:40, and ultrasonically disperse after stirring to obtain a mixture;

2. Add the nitric acid solution and the ammonia solution of bismuth nitrate to the mixture obtained in step 1 simultaneously in the form of atomization and stir, and the pH value of the system is controlled at 8 during the addition process;

3. After the addition, let it stand for 4 hours. After pouring out the clarified water in the container, pour the reinforcement into a hydrothermal kettle and keep it warm at 140°C for 4 hours. After natural cooling, pour the reinforcement into a mold and press it to obtain the reinforcement. prefabricated parts, demoulding;

4. Heat the prefabricated reinforcement at 500°C for 60 minutes, then put it into the mold and heat it to 520°C, then pour molten aluminum or aluminum alloy into the mold and pressurize to 100MPa, hold the pressure for 20 minutes and then release the mold. That is, the preparation of nano-bismuth oxide-coated ceramic phase reinforcement/aluminum matrix composite material is completed;

Wherein in the nitric acid solution of bismuth nitrate in step 2, the concentration of bismuth nitrate is 0.005mol/L, and the concentration of nitric acid is 0.05mol/L; The concentration of ammoniacal solution is 0.05mol/L;

In step 2, the mass ratio of Bi element to ceramic reinforcement is 1:40.

The scanning electron microscope image of the surface of the reinforcing body after natural cooling in Step 3 in this embodiment is shown in Figure 1: it can be seen that the coating is fine and evenly distributed.

The obtained nano-bismuth oxide coated ceramic phase reinforcement/aluminum-based composite material prepared in this example has a tensile strength of up to 350 MPa after testing, which is more than 15% higher than that of the existing composite material tensile strength (250-300 MPa). The damping performance at room temperature is more than doubled, and the high-temperature molding temperature can be reduced by nearly 200°C.

Claims (5)

1. the nano bismuth oxide coated ceramic strengthens the preparation method of body/aluminum matrix composite mutually, it is characterized in that the preparation method that the nano bismuth oxide coated ceramic strengthens body/aluminum matrix composite mutually realizes according to the following steps:

One, be 1: 40～80 pottery is strengthened body to mix with distilled water according to mass ratio, ultra-sonic dispersion after stirring gets mixture;

Two, all add to simultaneously in the step 1 gained mixture and stirring in the mode of atomizing solution A and ammonia soln, the pH value of system is controlled at 6～12 in the adding procedure;

Three, leave standstill 1～5h after add finishing, outwell the water of clarifying in the container after, will strengthen body and pour in the water heating kettle, at 100～300 ℃ of lower insulation 1～24h, will strengthen body behind the naturally cooling and pour into and suppress the prefabricated component of acquisition enhancing body, the demoulding in the mould;

Four, will strengthen the prefabricated component of body at 400～1100 ℃ of lower insulation 30～120min, then put into mould and be heated to 450～550 ℃, pour into the aluminum or aluminum alloy of melting in the mould again and be forced into 80～200MPa, the preparation that the nano bismuth oxide coated ceramic strengthens body/aluminum matrix composite is mutually namely finished in the demoulding behind pressurize 15～30min;

Wherein solution A is the salpeter solution of Bismuth trinitrate or the hydrochloric acid soln of bismuth chloride in the step 2; The concentration of Bismuth trinitrate is 0.00001～0.2mol/L in the salpeter solution of Bismuth trinitrate, and the concentration of nitric acid is 0.00001～1mol/L; The concentration of bismuth chloride is 0.00001～0.2mol/L in the hydrochloric acid soln of bismuth chloride, and the concentration of hydrochloric acid is 0.00001～1mol/L; The concentration of ammonia soln is 0.001～1mol/L;

The Bi element is 1: 5～80 with the mass ratio that pottery strengthens body in the step 2.

2. nano bismuth oxide coated ceramic according to claim 1 strengthens the preparation method of body/aluminum matrix composite mutually, it is characterized in that in the step 1 according to mass ratio being pottery to be strengthened body in 1: 60 to mix with distilled water.

3. nano bismuth oxide coated ceramic according to claim 1 and 2 strengthens the preparation method of body/aluminum matrix composite mutually, it is characterized in that in the step 2 that the pH value of system is controlled at 8 in the adding procedure.

4. nano bismuth oxide coated ceramic according to claim 3 strengthens the preparation method of body/aluminum matrix composite mutually, leave standstill 3h after it is characterized in that adding end in the step 3, after outwelling the water of clarifying in the container, will strengthen body and pour in the water heating kettle, at 140 ℃ of lower insulation 4h.

5. nano bismuth oxide coated ceramic according to claim 4 strengthens the preparation method of body/aluminum matrix composite mutually, it is characterized in that to strengthen in the step 4 prefabricated component of body at 500 ℃ of lower insulation 60min, then put into mould and be heated to 520 ℃, pour into the aluminum or aluminum alloy of melting in the mould again and be forced into 100MPa, the demoulding behind the pressurize 20min.

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