JPS6244547A - Composite aluminum alloy material - Google Patents

Abstract

PURPOSE:To provide superior heat resistance and workability to a composite Al material contg. short fibers as a reinforcing material by using an Al-Fe alloy as the Al alloy and adding an element for improving the heat resistance to the alloy. CONSTITUTION:One or more kinds of reinforcing materials selected among granules, whiskers and short fibers are dispersed in an Al alloy as a matrix to obtain a composite Al alloy material. At this time, the composition of the Al alloy is composed of 3-12wt% Fe, <10wt% one or more among Co, Cr, Ni, Mn, La Zr, V, Ce, Cu, Si, Mo and Ti and the balance Al.

Description

[Detailed Description of the Invention] [Technical Field] In recent years, aluminum and aluminum alloys are used as a matrix, and reinforcing materials such as silicon carbide fibers,
Aluminum composite materials with dispersed whiskers and particles are used in various fields, such as internal combustion engine parts.
It is attracting attention as an aluminum-based composite material with high specific strength and rigidity that can replace steel products.

The present invention relates to an aluminum alloy composite material which has high heat resistance and good workability among the aluminum-based composite materials.

[Conventional technology and its problems]

IJ-luxed fiber-reinforced composite materials include those that use long copper fibers as reinforcing materials, and long * H, il,
It can be divided into short fiber types (hereinafter referred to as short fibers) such as chopped fibers, whiskers, and particles made by cutting the fibers into small pieces. The former uses continuous fibers such as silicon carbide fibers, carbon fibers, alumina fibers, and boron fibers, and is produced by infiltration, high-pressure casting, and prepreg in which the reinforcing fibers are covered with a matrix alloy (formed by rehot pressing). It can be made by a method such as stacking fibers and matrix metal plates alternately and heating and pressing them in a vacuum.

However, although the Nagamui fiber-reinforced composite material made in this way has excellent specific strength, specific stiffness, and heat resistance, it can be used not only for forming processes such as forging, extrusion, and rolling to make products, but also for bending processes. It is difficult because it causes breakage. In other words, workability is poor. Therefore, the production cost is high because it has to be made to fit the shape of the product.Also, reinforcing fibers have high strength in the direction of the reinforcing fibers, but are not reinforced in the transverse direction at 90 degrees to the fiber direction. It has the disadvantage of having a directionality.

On the other hand, the latter short fiber-reinforced composite material is slightly inferior to the former in terms of strength, but it does not have the disadvantage of the directionality of the reinforcing fibers.
It has superior strength, rigidity, and wear resistance compared to matrix alloys alone. Moreover, it can be formed by forging, extrusion, etc.

As mentioned above, short fiber reinforced composite materials have some advantages over long fiber reinforced composite materials, but their strength decreases significantly at high temperatures. That is, heat resistance is poor.

This is because the short fiber reinforced type is more easily affected by the matrix metal than the long fiber reinforced type. That is, the strength of aluminum alloys decreases around 200°C, and the strength of the composite material decreases accordingly. Even fiber-reinforced composite materials with a matrix of silicon-based aluminum alloy, which is said to have good heat resistance, have a short fiber type with a strength of about 45 kVmm20 at room temperature but about 20 kg/mm at high temperatures.
It drops to 2. This improvement in heat resistance is a problem that needs to be solved in the development of short fiber reinforced composite materials.

[Structure of the invention and its operation]

In order to maintain high strength at high temperatures, which is a problem with short fiber-reinforced aluminum composite materials, in other words to increase heat resistance, Al-Fe is a matrix in which Fe is forcibly dissolved.
Uses a series alloy. Because the amount of Fe in this alloy exceeds the solid solubility limit, it cannot be made into a matrix by the commonly used casting or infiltration methods, so it can be made into a matrix by powder metallurgy using alloy powder made by rapid solidification. Ta. Regarding the alloy components, the amount of Fe is set at 5% or more because it is necessary to provide heat resistance to the alloy, and the amount of Fe is set at less than 12% because if the amount of Fe is increased too much, primary crystal compounds will occur in the alloy powder. This is because the specific gravity of the matrix alloy increases and the specific strength of the composite material decreases. Co, Cr, Ni, Mn
, La, Zr.

V, Ce, Cu, Si, Mo, Ti (The addition of D further improves the heat resistance, and the reason why the amount of these additions was set to less than 10% in total was because it was feared that the specific strength would decrease for the same reason as the restriction on the amount of Fe. It is.

As reinforcing materials, short fibers such as silicon carbide fiber, carbon fiber, alumina fiber, and boron fiber, as well as silicon carbide, silicon nitride,
Whiskers such as alumina, and one or more types of particles such as silicon carbide, silicon nitride, alumina, etc. are added depending on desired performance such as strength and wear resistance, and also considering economic aspects.
These contents can be determined.

〔Example〕

Ten types of samples according to the present invention, numbered 1 to 10 in the table, were prepared. That is, as a matrix: Fe and Ce
, Cr, Mo, Co, Ni, La
, S'i, Mn, etc. are within the limits of the present invention, and are rapidly solidified by gas atomization (alloy powder with a grain size of 105μη or less is used, and the reinforcing material is made of various short metals shown in the table). Using fibers, whiskers, and particles, after mixing with matrix alloy powder, the process of cold forming, degassing, and hot forming is performed to form a 80mm0,10mm
A composite material of 0nml of this layer was prepared according to the *ioo time retention example.

In addition, as a comparative example, as shown in the table, the matrix alloy was not according to the present invention, that is, 11° and 14. late 1
6. In addition to the four types mentioned above, the matrix alloy is one according to the present invention that does not use reinforcing material, that is, NQ 12 + N[l
Two types of No. 15, one type of simple aluminum alloy that does not use a matrix alloy according to the present invention and no reinforcing material, that is, No. 11, and these seven types of comparative example alloy materials were prepared according to the composite material of the above example. I made it.

Next, after extruding the 10 types of composite materials according to the embodiments of the present invention and the 7 types of comparative alloy materials, the
After holding at the test temperature of 'C for 100 hours, a tensile test was conducted at that temperature. The heating temperature during production was set not to exceed 400°C so that Fe dissolved in solid solution would not form coarse precipitates. These results are also listed in the table.

According to the table, 1 to 10 of the examples according to the present invention are 11. Comparing the high temperature tensile strength after 100 hours at 00°C with 142Nn16r described in 17, the example of the present invention has a tensile strength of 2'', 5 kgf/
Although it shows more than mm2, the comparative example is 13.5 kgf
/mm2 or less. In addition, a simple heat-resistant aluminum alloy N[112, which uses the aluminum alloy according to the present invention in the matrix but does not use a reinforcing material, and a composite material Nn1. Comparing the high temperature tensile strength with Nch2, the example of the present invention shows a higher value. Comparing slow 7 and slow 15, the same can be said for 1ζ. Among the examples of the present invention, Kan6 and Sho69M7 have slightly lower high temperature strength than other examples 1flj. and \(L7 is Fefr of the present invention)
This is because it is close to the lower limit of the amount. To comparative example 1 to 1
6 is a mere 6061 aluminum alloy that is neither a matrix alloy nor an alloy of the present invention, and does not use any reinforcing material,
It shows the lowest test result in this test. On the other hand, this seems to clearly represent the effects of the present invention.

〔Effect of the invention〕

As mentioned above, in the fiber-reinforced aluminum composite material, which has excellent performance in specific strength and specific stiffness, short fiber type is selected as the reinforcing material, and a heat-resistant Al-Fe alloy is selected as the matrix aluminum alloy. By adding an additive element that improves heat resistance, it is possible to improve the disadvantages of poor workability and heat resistance as a fiber-reinforced aluminum composite material, which greatly contributes to expanding the range of uses.

Claims (1)

[Claims] One or two of particles, whiskers, and short fibers as reinforcing materials
In a composite material in which at least one species is dispersed in an aluminum alloy as a matrix, the aluminum alloy comprises:
Contains 3 to 12 wt% of Fe, Co, Cr, Ni, Mn,
An aluminum alloy composite material comprising less than 10 wt% of one or more of La, Zr, V, Ce, Cu, Si, Mo, and Ti, with the remainder consisting of Al and impurities.