CN113857464A

CN113857464A - Preparation method of fiber reinforced aluminum matrix composite

Info

Publication number: CN113857464A
Application number: CN202111135526.7A
Authority: CN
Inventors: 刘静; 李峰; 高濂
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2021-12-31

Abstract

The invention provides a preparation method of a fiber reinforced aluminum-based composite material, which comprises the steps of preparing fibers into a porous prefabricated body with a certain shape in advance, heating the porous prefabricated body and aluminum alloy together in inert gas argon to a target temperature to liquefy the aluminum alloy, introducing magnesium nitride steam to enable the liquid aluminum alloy to infiltrate the whole ceramic prefabricated body through capillary action, vacuumizing, cooling and finally obtaining the composite material. The aluminum matrix can be effectively prevented from being oxidized by heating in inert gas; changing the reaction gas after reaching the target temperature, and improving the wettability of the fiber surface and the liquid aluminum alloy through magnesium nitride steam; and the gas in the structure is further discharged by vacuumizing, so that the density of the composite material is improved. The invention is beneficial to improving the interface bonding strength between the fiber and the aluminum alloy and exerting the composite effect and performance advantage of the composite material to the maximum extent; meanwhile, the molding of the component is realized through fiber preforming, and the method is particularly suitable for small-batch production of metal parts with complex structures and high requirements on mechanical properties.

Description

Preparation method of fiber reinforced aluminum matrix composite

Technical Field

The invention relates to the technical field of metal matrix composite materials, in particular to an infiltration preparation method of a fiber reinforced aluminum matrix composite material.

Background

Metal matrix composites have received much attention due to their excellent properties. The fiber reinforced aluminum matrix composite has high specific strength and high specific modulus, has good wear resistance, electrical conductivity, thermal conductivity, dimensional stability and high temperature resistance, and shows great application potential in the fields of aerospace, automobiles, electronics, machinery and the like. The preparation method of the fiber reinforced aluminum matrix composite material comprises a diffusion bonding method, a powder metallurgy method, an air pressure casting method and a melting infiltration method. The main problems of the methods are that the fiber damage is large, the distribution is uneven, the interface bonding force with metal is weak, and the like, and in order to obtain good interface bonding, the fiber needs to be pretreated or specific alloy elements are added, the process is complex and has more limitations, so that the fiber reinforced aluminum matrix composite material is not applied to large-scale industrialization at present.

Accordingly, those skilled in the art have been devoted to developing a method for preparing a fiber-reinforced aluminum-based composite material.

Disclosure of Invention

In view of the above defects in the prior art, the technical problems to be solved by the present invention are the problems of large fiber damage, uneven distribution, weak interfacial bonding force with metal, etc. in the preparation process of the fiber reinforced aluminum matrix composite.

In order to solve the above technical problems, an object of the present invention is to provide a method for preparing a fiber-reinforced aluminum-based composite material, which is simple and easy to perform, and the obtained composite material has good interface bonding and uniform fiber distribution between fibers and a matrix, and simultaneously minimizes damage to the fibers, and is suitable for fibers and aluminum alloys having various compositions.

In order to achieve the above object, the present invention provides a method for preparing a fiber-reinforced aluminum matrix composite, the method comprising preparing fibers into a porous preform having a specific shape in advance, changing wettability of the fibers in an atmosphere furnace by magnesium nitride vapor, and finally immersing molten aluminum alloy into the fiber preform by capillary action to obtain a high-performance fiber-reinforced aluminum matrix composite. The method mainly changes the wettability of the fiber, improves the capillary force, sucks the liquid aluminum alloy into the fiber preform, effectively avoids the damage of mechanical means to the fiber, simultaneously avoids the conditions of uniform fiber distribution such as powder metallurgy and casting method, and is suitable for preparing metal parts with complex structures and higher requirements on mechanical properties in batches.

In order to achieve the above object, the present invention provides 1 a method for preparing a fiber reinforced aluminum matrix composite, comprising the steps of:

A1. forming the fibers into a shaped porous preform;

A2. heating the porous preform and the aluminum-based material to a target temperature in an inert gas atmosphere;

A3. and introducing magnesium nitride steam at the target temperature, preserving the heat for a period of time, removing air bubbles in the alloy after the aluminum-based material is completely immersed in the porous prefabricated body formed by the fibers, and cooling to obtain the fiber reinforced aluminum-based composite material.

Further, in the step a1, the fiber is a pure phase fiber of any one of carbon fiber, alumina, silica, zirconia, spinel, mullite and silicon carbide base, or a composite phase fiber of any combination of several of them.

Further, the diameter of the fiber in step A1 is between 50nm and 20 μm.

Further, the porosity of the porous preform in step a1 is 50 to 99%.

Further, the aluminum-based material in step a2 is liquid aluminum or an aluminum alloy.

Further, the aluminum alloy is a magnesium aluminum alloy.

Further, the target temperature in step A2 is 700-950 ℃.

Further, in the step a3, the inert gas is one of argon, helium, neon, krypton, xenon, and radon.

Further, the method for removing the bubbles in the alloy in the step a3 is vacuum pumping or pressure treatment.

Further, the period of time in step a3 was 30 minutes.

The fiber preform is treated by the simple magnesium nitride steam, so that the wettability of aluminum and aluminum alloy on the fiber is changed, the aluminum alloy and the fiber can be simply compounded, and the problems of difficult and complicated manufacture of the fiber reinforced aluminum-based composite material are solved.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a schematic flow chart of a preferred embodiment of the present invention;

FIG. 2 is a scanning electron micrograph of a porous preform made of alumina fibers according to an embodiment of the present invention;

FIG. 3 is a scanning electron micrograph of an alumina fiber reinforced aluminum sample according to an embodiment of the present invention;

FIG. 4 is a graph showing the mechanical compression curves of the samples according to the example of the present invention.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Example 1

The implementation flow of the preparation method of the fiber reinforced aluminum matrix composite material is shown in figure 1. Alumina fiber with the diameter of about 200nm is made into a cuboid prefabricated body, and the porosity is about 90 percent. Placing 1g of the prefabricated body and 10g of the pure aluminum block in an atmosphere furnace in a laminated mode, introducing argon to protect, heating to 900 ℃, introducing steam generated after magnesium nitride is heated to 900 ℃ into the atmosphere furnace, preserving heat for 30 minutes, then vacuumizing for 5 minutes by using a mechanical pump, and naturally cooling to room temperature. The used alumina preform is shown in fig. 2, the scanning electron microscope of the obtained alumina fiber reinforced aluminum sample is shown in fig. 3, the mechanical property of the fiber reinforced aluminum sample 1 shown in fig. 4 is the compressive strength of 370MPa, which is much higher than 160MPa of pure aluminum, and the mechanical property is obviously enhanced.

Example 2

This comparative example is substantially the same as the method of example 1, except that: in this comparative example, magnesium nitride was directly produced at a high temperature by replacing magnesium nitride vapor with metal magnesium and nitrogen. The method comprises the following specific steps:

alumina fiber with the diameter of about 200nm is made into a cuboid prefabricated body, and the porosity is about 90 percent. Placing 1g of the prefabricated body and 10g of the pure aluminum block in an atmosphere furnace in a laminated mode, placing 1g of metal magnesium at a position 3cm away from the aluminum block, introducing argon for protection, heating to 900 ℃, introducing nitrogen, reacting the metal magnesium with the nitrogen to generate magnesium nitride, preserving heat for 30 minutes, vacuumizing for 5 minutes by using a mechanical pump, and naturally cooling to room temperature. The mechanical properties of the resulting sample are the fiber reinforced aluminum sample 2 of fig. 4, with a compressive strength of 375 MPa.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. The preparation method of the fiber reinforced aluminum matrix composite is characterized by comprising the following steps:

A1. forming the fibers into a shaped porous preform;

2. The method for preparing a fiber reinforced aluminum-based composite material according to claim 1, wherein the fiber in step a1 is a pure phase fiber of any one of carbon fiber, alumina, silica, zirconia, spinel, mullite and silicon carbide or a composite phase fiber of any combination thereof.

3. The method of preparing a fiber reinforced aluminum matrix composite according to claim 1, wherein the diameter of the fibers in step a1 is between 50nm and 20 μm.

4. The method of preparing a fiber-reinforced aluminum-based composite material according to claim 1, wherein the porosity of the porous preform in the step a1 is 50 to 99%.

5. The method of claim 1, wherein the aluminum-based material in step a2 is liquid aluminum or an aluminum alloy.

6. The method of claim 1, wherein the target temperature in step A2 is 700-950 ℃.

7. The method of claim 1, wherein the inert gas in step A3 is one of argon, helium, neon, krypton, xenon, and radon.

8. The method for preparing a fiber-reinforced aluminum-based composite material according to claim 1, wherein the method for removing bubbles from the alloy in step a3 is vacuum pumping or pressure treatment.

9. The method of making a fiber reinforced aluminum matrix composite as set forth in claim 5 wherein said aluminum alloy is a magnesium aluminum alloy.

10. The method of preparing a fiber reinforced aluminum matrix composite according to claim 1 wherein the period of time in step a3 is 30 minutes.