JPS5953338B2 - Method for manufacturing aluminum matrix composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aluminum composite material, and is intended to obtain an aluminum matrix composite material that is particularly light and has excellent shock absorption properties.

In the present invention, aluminum is not limited to pure aluminum (e.g. 99.9% AI) but also AI-4,5Cu (A
CIA), Al-4,5Si-4Cu (AC2A)
, Al-6,3Si-3,8Cu (AC2B),
Al-6Si-3Cu (AC2C), Al-125
i (AC3A), Al-93i-0,5Mg-0,
5Mn (AC4A), Al-95i-3Cu (AC
4B), Al-75i-0,3Mg (AC4C), etc.

Also, pumice refers to a natural or artificially obtained foam stone that has minute air holes.

In recent years, aluminum foam has attracted attention as a lightweight material with high shock absorption properties.

Foamed aluminum is produced by, for example, adding Ti to molten aluminum, then adding Mg to melt it, then adding Si when the molten alloy solidifies, and then stirring it thoroughly when the molten alloy has cooled down to an appropriate temperature by natural cooling. It is manufactured by casting in a heated mold.

Although this foamed aluminum has the above-mentioned excellent properties, it has drawbacks such as a complicated manufacturing process and high manufacturing cost.

The present invention takes the above-mentioned points into account, and aims to provide a product that has a simple manufacturing process and low manufacturing cost, and which has properties comparable to those of foamed aluminum.

The present invention will be explained below.

The aluminum matrix composite material according to the present invention has a large number of pumice stones 2 dispersed in aluminum 1, as shown in FIG.

A suitable pumice stone 2 has an average diameter of 1 to 10 mm.

If this is too fine, the matrix of aluminum 1
This is because it is difficult to combine with pumice, and if it is too large, it becomes difficult to increase the mixing ratio of pumice.

Further, it is preferable that the proportion of the pumice stone 2 in the whole is 50 to 70 parts by volume, and that the specific gravity of this composite material is 1.8 to 2.1.

This is because if the amount of pumice 2 is too large, the strength of the composite material will be significantly reduced, and if it is too small, the lightness and impact absorption properties will be impaired.

This aluminum matrix composite material is manufactured as follows.

First, as shown in Fig. 2, the mold 3 is filled with pumice 2 in advance and the mold 3 is preheated.
A temperature of 0 to 320°C is suitable.

Next, molten aluminum 4 was infiltrated into the mold 3 under pressure and solidified.

This pressing force is preferably 50 to 100 g/cHf.

If it is less than this, aluminum will not penetrate sufficiently,
Moreover, if it is too large, there will be problems with the strength and operability of the mold 3.

The aluminum matrix composite material thus obtained has a structure in which pumice 2 with a light specific gravity is filled in place of the foamed aluminum cavity, so that the specific gravity and shock absorption properties are comparable to those of the foamed aluminum.

Moreover, the manufacturing method for this aluminum matrix composite material is extremely simple compared to foamed aluminum, and has advantages such as lower cost.

Next, an experimental example of the present invention will be explained.

Experimental example 1 A mold was filled with pumice in advance, and molten aluminum was infiltrated into the gap under pressure to form a mold of 130 mm x 60 mm.
A square piece of 100 mm in diameter was manufactured.

The manufacturing conditions are shown in Table 1.

Note that 99.9% Al was used for the matrix, the preheating temperature of the mold was 280 to 320°C, the casting temperature was 820°C, and the pressurization holding time was 120 seconds.

A1-3 in the above table. With A5.16.6, the aluminum matrix composite material according to the present invention could be obtained, but with A5.16.6, the aluminum matrix composite material according to the present invention could be obtained.
In sample No. 4, the gaps between the pumice stones were narrow, and the molten metal did not completely infiltrate, making it impossible to obtain the desired sample.

In addition, in the case of A7, the pumice was microscopic and spherical, so it could not be combined with the matrix.

Experimental Example 2 Next, using the sample (A3) obtained in Experimental Example 1, a compression test, a dynamic compression test, and an impact test were conducted to examine its strength and impact absorption properties.

Compression test was performed using JS type autograph (2Qt, Shimadzu Corporation)
This was done using

The test conditions were: crosshead speed 20mm/min;
Chart speed 5mm/min, test piece 20mm
It was a rectangular test piece measuring 20 mm x 30 mm, and vaseline was used as a lubricant on both the upper and lower surfaces of the pressurized surface.

The load-displacement diagram is shown in FIG. 3 by curve a1.

The dynamic compression test was conducted using a PK-VK-160 type nutkl joint press (155 t, AIDA).

As the test conditions, a slide speed of 30 mm/sec was selected.

The stress-strain diagram is shown in FIG. 4 by curve a2.

The impact test was performed using a Charpy type impact tester (capacity.

30 kg-m).

The test conditions were that the total weight of the pendulum system was 26.150 kg and the lifting angle of the mallet was 138.0°.

The test piece used was a No. 5 test piece for a Charpy impact tester (10 mm x 10 mm x 55 mm) specified by JIS.

However, it was made without Notsuchi.

The result of measuring the absorbed energy was 1 to 3 kg-m.
It was within the range of

Comparative Example In contrast, foamed aluminum having a specific gravity of 0.16 to 0.41 was prepared, and an impact test was conducted in the same manner as in Experimental Example 2.

As a result, the amount of impact energy absorbed is 2.56~4.3
It was in the range of 2 kg-m.

In this case, the weight specific absorption capacity is 46.0×1 at 50% strain.
It was 03 to 117.3 kg-cm/kg.

From the results shown in Figures 3 and 4 and the results of the impact test,
It is recognized that the composite material according to the present invention is comparable to foamed aluminum in terms of strength and impact energy absorption, considering ease of manufacture.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the composite material according to the present invention, Fig. 2 is an explanatory diagram showing the manufacturing method of the composite material, Fig. 3 is a load-displacement diagram regarding compressive strength, and Fig. 4 is a dynamic diagram. FIG. 1... Aluminum, 2... Pumice, 3
······Mold.

Claims (1)

[Claims] 1 After filling a preheated mold with pumice stones with an average diameter of 1 to 10 mm, apply molten aluminum to the gaps between the pumice stones with a pressure of 50 to
A method for producing an aluminum matrix composite material, which comprises solidifying it by infiltrating it under pressure at 100 kg/cm2.