JP2569418B2 - Manufacturing method of superplastic aluminum nitride particle reinforced aluminum alloy composite material by hot extrusion and hot rolling and its processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications] The present invention relates to aluminum nitride particles.
Aluminum alloy contained as reinforcement, yet superplastic
The present invention relates to a method for producing a composite metal material that causes deformation characteristics.

[0002]

[Prior art] Ceramic whisker or particle reinforced aluminum
Minium composite material has a specific elastic modulus of about 2 which is
Twice the specific strength, comparable to titanium alloy, and heat resistant
Excellent heat resistance, abrasion resistance, thermal dimensional stability, and thermal conductivity.
Aerospace as well as medium and high temperature mechanical parts such as
It is being applied to structures in the field. In recent years,
It is also expected to be applied to packages of electronic devices such as semiconductors
I have.

[0003] In particular, this composite material is used in the aerospace field, etc.
It has a complex shape, a large surface area, and a three-dimensional shape.
It is necessary to press-mold the structure. Because of this,
The composite material can be rolled into a thin plate shape.
The ability to press-mold composite materials, and the material after molding
It is necessary that the properties are not inferior to those before processing. Against this
One of the technological solutions to
Attempts have been made to develop plasticity.

Conventionally developed superplastic ceramic whis
Power or particle reinforced aluminum composites with reinforced materials
Is silicon carbide SiC or silicon nitride Si3 N4 Ceramic
Cuswhisker or particles are used, and aluminum
After mixing with the alloy powder, pressure sintering is performed.
(Integral treatment-aging treatment-warm rolling-recrystallization treatment)
The crystal grains of the matrix are refined and superplasticity is developed.
I have. For example, silicon carbide whisker reinforced 2124 al
The minium composite material is formed into a sheet shape by rolling after forging.
About 0^.2 About 350% superplastic elongation occurs every second
You. 7064 aluminum composite material reinforced with silicon carbide particles
The ingredients are manufactured in the same manner as^.0001 distortion per second
It produces about 500% superplastic elongation at speed. Again
Akira et al. Strengthened silicon nitride whiskers 2124, 606
1, 7064 Aluminum composite material extruded only, forged
Hot extrusion after fabrication or rolling after extrusion
Do about 0^.From 250% to 60 at the strain rate per second
A total elongation of 0% was achieved.

[0005] However, conventionally, SiC and Si3 N4 Enhanced with
Superplasticity has been discovered except for composite materials
did not exist. Therefore, superplastic ceramic whiskers or
Particle reinforced aluminum composites are less common
Therefore, superplastic working could not be applied.

[0006]

[Problems to be solved by the invention] Aluminum based composite
Silicon carbide SiC and silicon nitride Si
Three N4 In addition to whiskers and particles, titanium carbide TiC particles,
Lumina particles, aluminum nitride AlN particles, boride T
iB2 Particles and the like are used. Among them, AlN particles
Si3 N4 The same nitride as, very hard and smells hot
Stable, high electrical insulation and thermal expansion coefficient
Is the same as silicon and has high thermal conductivity.
The use of is also expected. AlN particle reinforced composite material
It is said to have a high modulus of elasticity and excellent high-temperature strength.
Or SiC or Si3 N4 Inferior to whisker and particle reinforced composites
It is expected that a high-strength composite material can be manufactured without any problem. Only
Of ceramic whiskers and particle-reinforced composite materials
The problem is that the fracture toughness is low and the workability is poor.
Therefore, a high-performance complex that expresses superplasticity and is easy to form.
It is necessary to make a composite material.

However, when these composite materials are subjected to superplastic deformation at the temperature at which superplasticity occurs, cracking occurs at the interface between the reinforcing material and the aluminum matrix unless sliding deformation occurs on the interface, and large elongation cannot be generated. Will be. Therefore, for superplasticity of the composite material, the crystal grains of the matrix are fine and the slip deformation at this interface is important.

[0008]

[Means for Solving the Problems] Therefore, in the present invention,
In order to solve the above problems, aluminum nitride particles
Extrusion and rolling
Adopt the superplasticity development process of engineering. AlN particles are nitrided
Since it has the same nitrogen element as silicon whiskers and particles, the interface
Aluminum solid with low solidus temperature that enables slip deformation
It is thought that it has chemical conditions that can form a solution
You. In addition, thermomechanical treatment combining extrusion and rolling
The method is an aluminum solid solution with a high concentration of magnesium Mg
Mechanical conditions to form a thin phase at the composite interface
It is thought that it is possible. The aluminum nitride particles are
Since there is no reaction product with the luminium matrix,
A clean interface.

At the superplastic temperature, the solid phase temperature of the solid solution is lower than that of the ground matrix, so that the matrix easily becomes a liquid phase even when the matrix is in a solid or semi-molten state. Slip deformation easily occurs during the heating. Further, at a high temperature of the AlN particles, the coarsening of the crystal grains is suppressed, and the crystal grains of the matrix are refined. Due to these two effects, superplasticity is developed in the composite material at a high speed.

In the present invention, aluminum nitride Al
N series and 2000 series and 5000 series with particle size of 44 μm or less,
Or 6000 series aluminum alloy powder and AlN particles
So that the volume content of
With plastic balls in an organic solvent such as Knoll
Mix uniformly for at least 24 hours, and then mix the powder.
5 minutes or more at 450 ° C to 600 ° C in air
After applying pressure of 50 MPa or more and sintering under pressure, temperature 4
Pressing at an extrusion ratio of 10 or more from 50 ° C to 600 ° C
The material is extruded, and the material is pressed at a predetermined temperature.
Superplastic composite material can be made
Manufactured. In this case, preferably, the material is heated to 300 ° C.
Rolling at a temperature of from 550 ° C to a strain of 1.0 to 4.0
To make a thin plate with a thickness of 0.1 mm or more
Is done. Further, in the present invention, the superplastic composite material
At a temperature of 450 ° C. to 600 ° C., from 0.01 to 10
Forming by tensile deformation at a strain rate of seconds, from 150%
By superplastic deformation processing showing a total elongation of 500%
The superplastic composite material is subjected to superplastic forming.

EXAMPLES Examples of the present invention will be described below.

[0011] Example 1  Rod-like aluminum nitride particle reinforcement 212 having a diameter of 40 mm
Extrusion processing at 500 ° C for 4 aluminum composite material
And process it into a 4 mm wire rod.
Wrapped in stainless steel plates and tubes, at temperatures between 500 ° C and 580 ° C
Heat in the range, strain about 0^.With a rolling reduction of 1 or less
To roll. Repeat until the thickness is about 1mm
Perform rolling.

[0012] FIG. 1 shows the results. Extrude from Figure 1
Rolled aluminum nitride particles reinforced after processing 21
The total elongation of the 24 aluminum composite has a strain rate of 0^.Every 3
It was 160% in seconds.

Embodiment 2  Aluminum nitride particle reinforced 6061 aluminum composite
Extrusion at 500 ° C and extrusion ratio of 44
Further, rolling was performed under the same conditions as in
^.A thin composite material having a thickness of 1 mm or more is manufactured.

FIG. 2 shows aluminum nitride particle reinforced 6061.
It is a relationship between the total elongation and the strain rate when the aluminum composite material is subjected to a tensile test at 600 ° C. Figure 2 shows ^0. 1 to ^1.0 to total elongation at a high strain rate of about 300% or more per second was obtained.

[0015]

【The invention's effect】 In the present invention described above, the sheet-like composite
The material was subjected to a tensile test at 545 ° C.^.3 or
1^.0 With a remarkably high strain rate per second, 160% to 30%
It is found that superplasticity of high total elongation of 0% or more is developed.
Was. Therefore, high thermal conductivity as well as high specific strength and high specific elastic modulus
Expected Aluminum Nitride Particle Reinforced Aluminum Alloy Duplex
Used for automotive radiators, semiconductors, etc. using composite materials
Parts of heat exchangers such as heat pumps
You. Also, this composite material develops superplasticity at high speed.
If it is possible to efficiently mold large structures in the aerospace field,
Conceivable.

[0016]

[Brief description of the drawings]

[ FIG. 1 shows a sheet-like aluminum nitride particle reinforced 2124
It is a graph showing the relationship between the total elongation and the strain rate when the aluminum composite material is subjected to a tensile test at a temperature of 545 ° C.

FIG. 2 is a graph showing the relationship between total elongation and strain rate when a tensile test is performed on a sheet-like aluminum nitride particle reinforced 6061 aluminum composite material at 600 ° C.

Claims (3)

(57) [Claims] 1. An aluminum nitride AlN particle having a particle size of 44.
2000 μm or 5000 μm or 6000 μm aluminum alloy powder having a particle size of μm or less is uniformly mixed with a plastic ball for at least 24 hours in an organic solvent such as ethanol so that the volume content of AlN particles becomes 0.05 to 0.25. After mixing and sintering the mixed powder by applying a pressure of 50 MPa or more in a vacuum at a temperature of 450 ° C. to 600 ° C. for 5 minutes or more at a temperature of 450 ° C. to 600 ° C., at an extrusion ratio of 10 or more, Add extrusion processing and update
Then, this material is rolled at a predetermined temperature to form a thin plate.
A method for producing a superplastic composite material, comprising: 2. A scissors material in steel materials such as stainless steel plate or tube, strain amount at a temperature of 550 ° C. from 300 ° C. 1.0
The method for producing a superplastic composite material according to claim 1 , wherein rolling is performed at a pressure of 4.0 to 4.0 to obtain a thin plate having a thickness of 0.1 mm or more. 3. The method of claim 1, wherein
The superplastic composite material at a temperature of 450 ° C to 600 ° C,
Superplastic deformation with tensile deformation at a strain rate of 0.01 to 10 per second and a total elongation of 150% to 500%
A superplastic forming method characterized by processing.