JPS60228645A - Aluminum alloy having high wear resistance and low thermal expansion and its production - Google Patents

Abstract

PURPOSE:To produce an aluminum alloy having high wear resistance and low thermal expansion by forming a thin strip obtd. by cooling quickly and solidifying the melt of a specifically composed alloy consisting of Si, Cu, Mg, Ni and Al to a billet then extruding the billet. CONSTITUTION:The melt 3 of the alloy contg. >=1 kind among 15-40wt% Si, 0.5-10% Cu, 0.5-5% Mg and 0.5-5% Ni and consisting of the balance Al and impurities is ejected from a nozzle 4 and is cooled quickly and is solidified by gaseous Ar, etc. to the contact point (o) of two rolls 1, 2 under rotation of a twin roll device to form the thin strip 5. The resulted strip 5 is formed into the billet by a press and after the billet is preheated to about 500 deg.C, the billet is put into a die and is extrusion-molded. The aluminum alloy which has excellent wear resistance and machineability and low thermal expandability and is suitable for a cylinder of an internal combustion engine, etc. is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION 5 The present invention provides a 1% aluminum alloy with excellent wear resistance and machinability and low thermal expansion, and an aluminum alloy with wear resistance and low thermal expansion that can be widely used as sliding parts such as cylinders. and its manufacturing method.

Aluminum alloys used in sliding parts such as internal combustion engine cylinders are required to have properties such as wear resistance and low thermal expansion.

Conventionally, hypereutectic aluminum-5 silicon alloys such as ACB A 390 have been used as aluminum alloys for internal combustion engine cylinders, but these alloys have high strength.

Elongation and machinability are insufficient, and primary silicon is coarse.

As a result, silicone loss occurs and specific wear increases.

There were drawbacks such as the occurrence of bulk and galling.

The present invention improves the above-mentioned drawbacks of the prior art and has a wear resistance of 6. .

Aluminum has excellent wear resistance and machinability, and low thermal expansion.

The purpose is to provide ram alloy and its manufacturing method.

do.

The alloy of the present invention contains 15 to 40 pieces of Si and CuQ in a weight ratio of 1.
5゜~10chi, MgO, 5~5chi, NiO,5
~5% of one kind.

Or it contains two or more kinds and the remainder consists of Al- and impurities.

Each component in the alloy of the present invention will be explained.

If the silicon content is less than 15 inches, the amount of primary silicon is small, the wear resistance is insufficient, and the coefficient of thermal expansion is large.

When it exceeds 40% and is rapidly cooled to form a thin ribbon, it is 3.15~ because it is difficult to refine primary silicon.

The range was set at 40 inches. Copper is used together with magnesium.

Provides hardening properties l21 mechanical strength, hardness, and wear resistance.

However, if the content is less than 0.5%, the above effects are not sufficient; if it exceeds 10%, the strength and elongation will decrease.

Therefore, it was set in the range of 05 to 10 inches. Magnesium is.

Together with copper, it imparts age hardening properties and improves mechanical strength, hardness, and wear resistance, but if it is less than 5%, the above effects are not sufficient, and if it exceeds 5%, thermal expansion will increase. 05
The range was 5 to 5. Nickel improves high temperature strength and thermal expansion, but if it is less than 0.5%, the above effect is not sufficient,
If it exceeds 5%, the strength and elongation will decrease, so 05 to 5%.
The range of

To produce the aluminum alloy of the present invention, first, the molten metal is rapidly solidified into a ribbon using a twin-roll device, and the resulting ribbon is formed into a billet by cold or warm pressing. It is hot extruded.

The present invention will be explained in detail below.

Example 1 200 t of alloy (2) having the composition shown in Table 1 was heated to a high temperature.

After the frequency melting, the molten Al metal 3 is applied to the contact point 0 of the two rolls of the rotating twin-roll device shown in FIG. 1 using Ar gas.

It was ejected from a nozzle 4 and rapidly solidified into a thin ribbon 5. The obtained ribbon 5 was wound and cold rolled at a pressure of 2 tons/di.

Pressed into a cylindrical billet with a diameter of 45mm and a height of 15III+.

It was molded into. The billet was heated to 500°C in an electric furnace in a nitrogen atmosphere.
After preheating at ℃ for 30 minutes, it was placed in an extrusion mold heated to 200 υ and extrusion molded. Obtained bar-shaped test snoring,.

For K, tensile strength, 0.2% proof stress, elongation ratio wear amount.

The coefficient of thermal expansion was calculated. Table 2 shows the results.

A comparative example of the present invention alloy (2) and the conventional cast material (1) is shown. As is clear from the table, the tensile strength 0.2 mm yield strength has increased significantly, and the specific wear coefficient of thermal expansion has conversely decreased.

Example 2 Alloy (3) 20Of as shown in Table 1 above was made into a bar-shaped sample by the same method as in Example 1, and the tensile strength and
The 0.2% proof stress, elongation, specific wear amount, and coefficient of thermal expansion are shown in Table 2 (3).

Examples 3 to 5 Alloys (4) (5) as shown in Table 1 as in Example 2
(Use 61 and process in the same way, (4) and (5) in Table 2.
The results of (6) and (6) were obtained.

The alloys (2) to (6) of the present invention are superior to the conventional alloy (1) in both tensile strength, yield strength elongation, and specific wear rate and coefficient of thermal expansion. In particular, the specific wear amount is lower than that of conventional alloy (1).

The coefficient of thermal expansion is also considerably small, making aluminum annulus particularly effective as a material for sliding parts.

Table-1 ・　4　・ Table-2 *100tj to 20.

As mentioned above, the present alloy is superior in terms of mechanical properties, wear amount, thermal expansion coefficient, etc., as shown in Table 2, compared to conventional wear-resistant alloys. In addition, since the molten metal is rapidly solidified, the primary crystal silicon is 2 μm or less, and the alloy has excellent machinability.

[Brief explanation of drawings]

FIG. 1 depicts a schematic diagram illustrating an overview of a twin roll device. 1.210-le. 3I molten metal, 5I thin strip. 0 5 ・　7　・ Figure 1 251-

Claims (2)

[Claims] (1) 5i15-40% and CuO, 5-10% by weight
%9ML05~5CH, NiO, 5~5% of one or more types. The remainder consists of Al and impurities. High wear resistance and low thermal expansion aluminum alloy. (2) 5i15-40% and CuO, 5-10% by weight
%, Mf. 05-5%, NiO, 5-5%, one or two or more kinds of alloy (with the balance consisting of Al- and impurities) is rapidly solidified into a molten ribbon, and the resulting ribbon is pressed into a billet. A method for producing a high wear-resistant, low thermal expansion aluminum alloy, which is characterized by forming and extruding it.