JPS6316459B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aluminum alloy material, particularly an aluminum alloy material excellent in wear resistance, low thermal expansion, high temperature strength, and heat resistance. Cylinder blocks, cylinder liners and pistons for internal combustion engines, as well as vane materials for compressors, etc., require properties such as excellent wear resistance, low thermal expansion characteristics, high-temperature strength, and heat resistance. Moreover, if these materials are made of aluminum alloy, important advantages such as weight reduction and speed increase will occur. However, there are still no sufficient aluminum alloys that have the above-mentioned required properties, and there are problems such as the inability to use aluminum alloy materials for the above-mentioned purposes and the addition of restrictions to the conditions for their use. is inherent. For example, as an alloy material with excellent wear resistance and low thermal expansion, the applicant of the present application previously published Si
Al-14~30%Si-0.5~5 with finely dispersed particles
%Cu-0.3~3%Mg alloy was proposed, but this alloy does not have sufficient heat resistance and high temperature strength. In addition, A4032 alloy (Al-12%
Si-0.9%Cu-1.1%Mg-0.9%Ni), for cast materials
A390 alloy (Al-17%Si-4.5%Cu-0.6%Mg) is known, but even with these alloys, 200
It does not have sufficient strength at high temperatures exceeding .degree. C., and its use is subject to significant restrictions on usage conditions, such as the number of rotations. The present invention has been made against this background, and its object is to provide an aluminum alloy having excellent wear resistance properties, low thermal expansion properties, high temperature strength properties, and heat resistance properties. The aim is to provide materials. In order to achieve the above object, the present invention uses Si: 15 to 35% on a weight basis,
Cu: 0.5-10%, Mg: 0.3-6% and Mn: 0.3
The aluminum alloy material was constructed so that the average grain size of Si particles was 5 μm or less, and the average interparticle distance was 10 μm or less. It is. In addition, in the present invention, Si: 15 on a weight basis
~35%, Cu: 0.5~10%, Mg: 0.3~6% and
Contains Mn: 0.3 to 4%, and further contains at least one of Fe: 0.3 to 9% and Ni: 0.3 to 9% (Fe
+Ni) in an amount of 1.0 to 10%, and has an alloy composition in which the balance is Al and unavoidable impurities, and the average grain size of Si particles is 5 μm or less and the average interparticle distance is 10 μm or less. Furthermore, the gist of the invention is to construct the aluminum alloy material. By adopting the configuration of the aluminum alloy material according to the present invention, an aluminum alloy material having excellent wear resistance, low thermal expansion, high temperature strength, and heat resistance could be manufactured for the first time. It also has excellent seizure resistance, and for this reason it is used in cylinder blocks of internal combustion engines,
The aluminum alloy material of the present invention can be suitably used in cylinder liners, pistons, compressor vane materials, etc., where conventional aluminum alloys cannot be used or where usage conditions are restricted. It contributes to weight reduction and speed increase, increases its technical value, and can also have a large economic effect. By the way, in the alloy components of the aluminum alloy material in the present invention, Si (silicon) is
By adding it, the wear resistance and seizure resistance of the target alloy material are significantly improved, and the coefficient of thermal expansion is reduced. In order to fully exhibit the effect of adding Si, the amount added must be at least 15%.
(on a weight basis, the same applies hereafter). However, adding too much Si will reduce machinability, have a negative effect on the life of the cutting tool, and will also reduce the surface roughness of the surface to be cut. The upper limit of its addition amount is 35% because it causes problems such as graininess. Further, Cu (copper) in the aluminum alloy material according to the present invention coexists with Mg, imparts age hardenability to the alloy, and improves room temperature strength and wear resistance. It also has the feature of improving high-temperature strength through solid solution hardening. These effects are not sufficient when the amount of Cu added is less than 0.5%, and when the amount of Cu added exceeds 10%, these effects become saturated and the corrosion resistance of the material is impaired. This may cause problems such as being damaged. Furthermore, Mg (magnesium), which is one of the main alloy components in the present invention, together with Cu, imparts age hardenability and improves room temperature strength and wear resistance.
Solid solution hardening also improves the high temperature strength of the material. This effect is not sufficient when the amount of Mg added is less than 0.3%, and when the amount added exceeds 6%, the effect becomes saturated and causes problems such as a decrease in ductility. . Furthermore, Mn (manganese), which is another main alloy component in the present invention, improves the heat resistance and high temperature strength of the material. If the amount added is small, the effect will not be sufficient, whereas if it is added in a large amount, not only will the effect become saturated, but the ductility will drop significantly. The amount of Mn added to obtain these effects is 0.3 to 4%, preferably 0.3 to 3%. The four main elements (Si, Cu, Mg,
In addition to the alloying components consisting of
may be added singly or in combination. These Fe and Ni improve the heat resistance of the material, each singly or in cooperation with each other,
It also has the effect of increasing high temperature strength.
Furthermore, if these elements are added in too small a quantity, they will not be able to fully exhibit their effects, and even if they are added in large quantities, the effect will be saturated and the ductility will be significantly reduced. As it turns out,
0.3-9% for Fe, 0.3-9% for Ni
Furthermore, these elements should have a total content (total amount of Fe and Ni) of 1.0 to 10%, preferably
Must be between 2.0 and 5.0. In addition, in the present invention, the aluminum alloy material that is present in the aluminum alloy material containing a predetermined amount of the above-mentioned alloy components
Regarding the Si particles, it is necessary to make the average particle diameter 5 μm or less and the average interparticle distance 10 μm or less, thereby achieving the object of the present invention well. However, if the average particle size of the Si particles exceeds 5 μm or the average distance between particles exceeds 10 μm, the cut surface will become uneven and the surface roughness will become rough. This is because if it exceeds the limit, problems such as increased tool wear during cutting will occur. Further, the aluminum alloy material according to the present invention can be manufactured according to various manufacturing methods so as to give the Si particle size and interparticle distance specified above in the alloy composition as described above. However, it is generally desirable to manufacture it by the following method. That is, first, an aluminum alloy having the alloy composition as described above is melted, and then the obtained molten alloy is rapidly solidified. The faster the cooling rate at this time, the more desirable it is since it is possible to obtain a high-performance material, and usually a condition of cooling at a cooling rate of 100° C./second or more is adopted. The faster the cooling rate from the molten alloy, the finer the size of the Si particles in the final product, which improves machinability and wear resistance. Specifically, the atomization method and the rapid solidification method (splat cooling, etc.) are applied, and especially in the former, aluminum powder with an average particle size of 200 μm or less is obtained by atomizing the molten alloy. Become. The aluminum alloy powder or flakes thus obtained are then molded into a predetermined shape. Specifically, (a) Pre-compression - Container filling -
High temperature vacuum degassing - extrusion, (b) pre-compression - sintering, (c)
Molding is performed through processes such as pre-compression, packaging, high-temperature vacuum degassing, and high-temperature, high-pressure compression processing (HIP processing). More specifically, in the step (a) above, the aluminum powder has a true density of 70
After pre-compression molding to about 80%, it is sealed in a predetermined container, heated to a high temperature of 350 to 500°C, evacuated, and degassed. Note that if this degassing treatment is insufficient, the final product may bulge or defects caused by the gas may remain, causing problems. Next, the pre-compression molded product (billet) of the degassed aluminum powder is
The material is heated to a temperature of 350 to 500°C and hot extruded at an extrusion ratio of 4 or higher to obtain an aluminum alloy material in the desired shape. At this time, if the extrusion ratio is small, the pressure bonding will be insufficient and defects will remain in the extruded material, causing a problem. Moreover, according to the method (c), instead of the extrusion process as described above, the aluminum powder obtained by the rapid solidification is molded by a well-known high temperature and high pressure compression process (HIP process). , it is used as the material for the purpose. Examples of the present invention will be shown below in order to clarify the present invention more specifically, but it goes without saying that the present invention shall not be construed in any way limited by the description of such examples. be. Note that the content ratios of alloy components in the examples are all expressed in weight %. Example After melting alloys of various compositions No. 1 to 14 shown in Table 1 below, 200
Aluminum alloy powder with an average particle size of 120 μm was produced at a cooling rate of ℃/second or higher. This powder was compression-molded to 75% of its true density by preliminary compression, then sealed in an aluminum alloy container, heated to 450°C, and degassed by evacuation. The various billets with a diameter of 152 mm thus obtained were heated to 450°C and then extruded to produce bars with a diameter of 40 mm. On the other hand, for alloy compositions No. 15 to 17 in Table 1, after melting, the diameter is
A 152 mm ingot was produced and then extruded at 450°C to produce a rod-shaped body with a diameter of 40 mm. Then, the various rods obtained were subjected to solution treatment at 500°C for 1 hour, and then
Water quenching was performed, followed by aging treatment at 175°C for 8 hours. For the materials (rods) obtained in this way, we measured the Si particle diameter and interparticle distance, and
A wear test, a tensile test, and a Bitkers hardness measurement were conducted to evaluate each performance. The results are shown in Tables 2 and 3 below. The wear test used in this performance evaluation was the Okoshi type wear test (load: 3.2Kg, running speed: 1m/
The tensile test was carried out at room temperature, 250℃, and 350℃ for a holding time of 100hr, and the Bitkers hardness was measured as it was (at room temperature). ) and 300
The test was carried out after heating at °C for 100 hours.

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【table】

[Table] As is obvious from the comparison of Tables 1 to 3, aluminum alloy materials according to the present invention: No. 1 to
The specific wear amount in No. 10 is as follows: Comparative alloys: No. 11 to 14, No.
15 (A4032) and No. 16 (A390), are sufficiently small, and have high temperature tensile strength and
The hardness after heating to 300℃ is greater than that of comparative alloys.
It is recognized that it has excellent high temperature strength and heat resistance.

Claims (1)

[Claims] 1. On a weight basis, Si: 15-35%, Cu: 0.5-10%,
It has an alloy composition containing Mg: 0.3 to 6% and Mn: 0.3 to 4%, with the balance consisting of Al and unavoidable impurities, and the average grain size of Si particles is 5 μm or less and the average interparticle distance is 10 μm or less. An aluminum alloy material with excellent wear resistance, low thermal expansion, high temperature strength, and heat resistance. 2 Based on weight, Si: 15-35%, Cu: 0.5-10%,
Contains Mg: 0.3 to 6% and Mn: 0.3 to 4%, and further includes at least one of Fe: 0.3 to 9% and Ni: 0.3 to 9% so that the amount of (Fe + Ni) is 1.0 to 10%. , the balance is Al and unavoidable impurities, and the average grain size of the Si particles is
An aluminum alloy material with excellent wear resistance, low thermal expansion, high-temperature strength, and heat resistance, with an average interparticle distance of 5 μm or less and an average interparticle distance of 10 μm or less.