JPH02209438A - Manufacture of aluminum alloy material - Google Patents

Abstract

PURPOSE:To obtain the Al-Si-Fe series alloy material having excellent ductility by subjecting shaped goods formed with Al-Si-Fe series alloy powder as raw material to solution treatment, quenching and artificial aging treatment. CONSTITUTION:The molten metal of an Al-Si-Fe series alloy contg., by weight, 15 to 35% Si and 0.3 to 9% Fe is rapidly cooled and is pulverized by an atomizing method, etc., and the powder is packed into an Al can or the like. The inside of the Al can is subjected to vacuum deaerating treatment and is thereafter forming by an extrusion or hot pressing method into the desired shape. The shaped goods are successively subjected to solution treatment at 460 to 500 deg.C, are thereafter to quenching treatment by using water or hot water and are successively to natural aging treatment or artificial aging treatment for the time shorter than that required for obtaining the maximum hardness at <=185 deg.C. The Al-Si-Fe alloy material having good tensile strength, elongation and fatigue resistance and having excellent workability can be obtd.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to an improvement in the manufacturing method of an aluminum alloy material,
In particular, it relates to a method for improving the ductility of materials obtained from Af-3i-Fe powder alloys.

(Background Art) Cylinder blocks, cylinder liners and pistons of internal combustion engines, as well as compressor vane materials, etc., require characteristics such as excellent wear resistance, low thermal expansion characteristics, high-temperature strength, and heat resistance. Therefore, in recent years, in order to manufacture these materials from lightweight aluminum (A2) alloys, materials containing a large amount of silicon (St) as an alloy component have been developed.
1-3i powder alloy has been proposed, and the applicant has previously developed an Af-3t-Fe powder alloy (
(See Japanese Patent Publication No. 63-16459).

By the way, in such aluminum alloys containing a large amount of St, since St precipitates during solidification,
Since it is difficult to cast, the molten alloy is usually rapidly cooled and solidified by a spraying method to obtain powder or flake alloy powder, and then the alloy material in the desired shape is formed from this alloy powder. things are being done. More specifically, since it is difficult to perform a molding operation directly from the obtained powder, the alloy powder is first classified, pre-compressed if necessary, and sealed in a designated can. The contents of the can are subjected to vacuum deaeration treatment, and then the can contents subjected to such deaeration treatment are subjected to a forming operation such as extrusion molding or hot pressing, and further molding processing such as forging. The alloy material is then processed to form the desired shape.

However, the Aj2-3t-Fe alloy material obtained by molding according to the above-mentioned normal molding operation has a 0.
There was no elongation rate of about 3 to 0.7%, and there was a problem that the material would crack during cutting or machining, or the edges of the material would be chipped.

(Solution Division B) The present invention was made against the background of the above circumstances, and the problem to be solved is that AffiSi-Fe
The objective is to improve the ductility of alloy materials.

(Solution Means) Therefore, in the present invention, in order to solve the above problems,
A molded product obtained from Aluminum 1 alloy powder containing 15 to 35% by weight of Si and 0.3 to 9% by weight of Fe as main alloy components was solution-treated at 460'C to 500°C, and then treated with water. Alternatively, hot water quenching and natural aging were performed;
After solution treatment at 00°C, water or hot water quenching is performed, followed by artificial aging treatment at a temperature of 185°C or less for a time shorter than that required to obtain maximum hardness.

(Function/Effect) In short, by applying heat treatment under specific conditions to a molded product obtained from alloy powder according to the method for producing an aluminum alloy material according to the present invention as described above, for the first time,
We were able to advantageously improve the ductility of the A/2-3i-Fe alloy material, which makes it easier to manufacture various parts and members such as connecting rods by cutting or machining the alloy material. In addition, it has become possible to effectively prevent the occurrence of cracks and chips in the material, and as a result, a significant improvement in workability has been achieved.

On the other hand, the properties such as good wear resistance, low thermal expansion, high temperature strength, and heat resistance obtained from the alloy composition containing St and Fe as the main alloy components are not impaired in any way by the manufacturing method according to the present invention. Therefore, the aluminum alloy material of the present invention can be used in various parts that require each of these performances, and these parts, as well as the machines and engines in which they are used, can be made lighter and faster. can be advantageously achieved.

Furthermore, the manufacturing method according to the present invention has the advantage that the above effects can be obtained without adding any new steps, in other words, without any new equipment investment.

(Specific structure) By the way, the aluminum alloy material in the present invention has silicon (St) and iron (Fe) as main alloy components, and St is 15 to 35% by weight and Fe is 0.3 to 9% by weight. It is contained in a proportion of % by weight.

Among these main alloy components, the addition of St significantly improves the wear resistance and seizure resistance of the target alloy material, and also lowers the coefficient of thermal expansion, and the addition amount is 15%. If it is less than 35%, no sufficient effect will be obtained, whereas if it exceeds 35%, the cutting performance will decrease, the life of the cutting tool will be adversely affected, and the surface roughness of the surface to be cut will become rough. It becomes like this. Furthermore, F
e has the effect of improving the heat resistance and high-temperature strength of the alloy material, and when added in an amount of less than 0.3%, a sufficient effect can be achieved, but when added in an amount exceeding 9%. Then, the effect becomes saturated and the ductility decreases significantly.

In addition to these side alloy components, depending on the performance required for the target alloy material, copper (Cu), magnesium (Mg), manganese (Mn), nickel (Ni), etc.
It goes without saying that it can be contained as appropriate. In addition, Cu coexists with Mg and has the effect of imparting age hardenability to the alloy material, improving room temperature strength and wear resistance, and further improves the high temperature strength of the alloy material by solid solution hardening. 0.5-10%
In addition, along with Cu, Mg imparts age hardenability to the alloy material and improves room temperature strength and wear resistance. It has the effect of improving strength, and is contained in a proportion of 0.3 to 6%. Furthermore, Mn improves the heat resistance of the alloy material and increases its high temperature strength, and is contained in a proportion of 0.3 to 4%. Furthermore, Ni works with Fe, the main alloy component, to improve the heat resistance of the alloy material and to increase the high-temperature strength.
It is contained in a proportion of .

When forming aluminum alloy powder from molten aluminum alloy containing such alloy components,
It is desirable to rapidly solidify the molten alloy as in the past. This is because the faster the cooling rate, the more the precipitation of St can be suppressed, the size of the Si particles in the final product becomes finer, and the machinability and wear resistance can be improved.

As for the angle and the cooling rate, a cooling rate of 100"C/sec or more is preferably adopted, and specifically, an atomization method, a rapid solidification method (splat cooling), etc. are applied. In particular, the former In this method, aluminum alloy powder having an average particle size of 200 μm or less can be obtained by atomizing the molten alloy.

In the method for producing an aluminum alloy material according to the present invention, the aluminum alloy powder thus obtained (including those in flake form) is first classified, sealed, or sealed in a conventional manner. After classification, pre-compression and can sealing, a series of vacuum degassing treatment and molding operations are performed to form the aluminum alloy material into the desired shape. In addition,
The purpose of the vacuum degassing treatment performed prior to the molding operation is to prevent defects such as blisters from occurring in the final molded product.

Further, various subsequent molding operations such as extrusion molding and hot pressing are performed on the deaerated aluminum alloy powder filled and sealed can in the conventional manner.

For example, in the case of extrusion molding, the degassing can is heated to a temperature of 400 to 480°C and hot extrusion is performed at an extrusion ratio of 4 or more to obtain an aluminum alloy material in the desired shape. The extrudate can be further processed, such as forging, if necessary.

In this way, it is possible to obtain an alloy material (material) in the desired shape.According to the present invention, the alloy material is subjected to solution treatment under specific conditions as described below. Treatment - A series of heat treatment operations such as quenching and temporary hardening treatment are performed continuously. and,
By performing a series of heat treatments under this specific condition,
This makes it possible to significantly improve the ductility of the target alloy material.

That is, in this specific series of heat treatments, first, the alloy material that has been subjected to extrusion molding, hot pressing, etc. as described above is held at a temperature of 460°C to 500°C, and the alloy material is solutionized. to be processed. The holding time is determined to be enough time for the alloy components to be sufficiently dissolved in the solid solution, and is generally selected within the range of 30 minutes to 24 hours, but the more specific solution treatment temperature and holding time may vary. , depending on the alloy composition, the shape of the alloy material, the size of the cross-sectional area, etc.
A decision will be made as appropriate. Note that if the solution treatment temperature is less than 460°C, the alloy material cannot have sufficient strength, while if it exceeds 500°C, the elongation of the alloy material will decrease.

Next, after solution treatment, quenching is performed using water or hot water as a medium. At this time, in order to give the alloy material sufficient strength, it is best to cool it as quickly as possible, but if the alloy material has a complex cross-sectional shape, hot water It is also effective to use

Further, as a hardening method, it goes without saying that any known method can be used, such as adding an alloy material into a medium or spraying a medium onto a residual material. In short, the quenching rate is appropriately determined depending on the alloy composition, shape, etc. of the alloy material, and the medium temperature and quenching method may be determined as necessary.

Furthermore, the alloy material subjected to such solution treatment and quenching is subsequently subjected to natural aging treatment or 185"
The series of heat treatments is completed by performing artificial aging treatment (hereinafter referred to as sub-aging treatment) at a temperature of C or less for a time shorter than the time required to obtain the maximum hardness. Furthermore, if the sub-aging treatment temperature exceeds 185°C, the alloy material will reach its maximum hardness during the temperature rise or in a very short time after the temperature rise, and then it will begin to soften, which will affect the strength of the alloy material, especially fatigue. In addition to reducing the strength, such softening does not improve the elongation of the alloy material, resulting in a lower elongation rate than that of the naturally aged alloy material and the sub-aged alloy material.

In addition, the more specific treatment temperature in sub-aging treatment is appropriately determined depending on the alloy composition and material shape of the alloy material, and similarly, the treatment time in natural aging treatment and sub-aging treatment also depends on the alloy composition and material shape of the alloy material. It will be determined appropriately depending on the shape and the aging treatment temperature.

The alloy material that has gone through all the steps described above will be used as a material for connecting rods, etc. The aluminum alloy material obtained by the present invention has a significantly improved elongation rate, so it cannot be cut or processed. This means that the material no longer cracks or the edges of the material are chipped during the cutting process.

(Examples) Below, some examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited in any way by the description of such examples. Needless to say, it is not something that can be accepted.

In addition to the following examples and the above-mentioned specific description, the present invention includes various changes, modifications, and changes based on the knowledge of those skilled in the art, as long as they do not depart from the spirit of the present invention. It should be understood that improvements and the like may be made.

First, Si: 17% by weight, Fe: 6% by weight, Cu: 4.
5% by weight, Mg: 0.5% by weight, Mn: 0.4% by weight, and the remainder is A! An Affi-3t-Fe-based alloy consisting of and unavoidable impurities was melted and an aluminum alloy powder was produced by an atomization method. Next, using the obtained alloy powder, after filling an A1 can with the alloy powder and sealing the can, a deaeration treatment was performed at a deaeration temperature of 480°C for 2 hours, and then a molding temperature of 450°C and an extrusion ratio of 1. Extrusion molding was carried out at No. 15, and a rod having a diameter of φ was molded for one day.

The bars thus obtained were subjected to various heat treatments shown in Table 1, and then their tensile properties and fatigue strength were examined. The test results are summarized in Table 1 below, along with the heat treatment conditions for each test material. Note that the solution treatment on each side was performed for 2 hours.

Table 1 As is clear from the results in Table 1, alloy materials whose solution treatment temperature is lower than 460'C (Comparative example: No. 1)
．． 3.5.10), none of them have sufficient tensile strength, and the alloy material whose solution treatment temperature is higher than 500°C (comparative example: No, 2.4.9.14) has low elongation. It is recognized that

In addition, from the perspective of aging treatment, alloy materials No. 5 to 9 were aged to obtain the highest hardness, so although the tensile strength was sufficient, the elongation was low.
For alloy materials No. 10 to 14, since over-aging treatment was applied,
Tensile strength has decreased, and fatigue strength has also decreased. Furthermore, it can be seen that the elongation rate was not sufficiently obtained.

On the other hand, in accordance with the present invention, the alloy materials (No. 15 to 20) in which the solution treatment temperature was maintained well and the aging treatment was performed by natural aging treatment or sub-aging treatment It can be seen that all of them have a good tensile strength of 55 Kgf/s" or more, an elongation of 1.2% or more, and sufficient fatigue strength.

In addition, from the same alloy used in the above test, the same bar material of <18 mmφ was extruded through the same process,
Furthermore, after forging these bars into connecting rod shapes, each bar was subjected to the same heat treatment as shown in Table 1 above. After machining the various alloy materials obtained in this way, such as machining bottle holes at the large end and small end, and machining bolt holes at the large end connection, the results were as follows. No. 15 ~ subjected to heat treatment according to the invention
Each of the alloy materials No. 20 was found to have good machinability without any cracks or chips.

Applicant: Sumitomo Light Metal Industries, Ltd.

Claims (2)

[Claims] (1) A molded product obtained from an aluminum alloy powder containing 15 to 35% by weight of Si and 0.3 to 9% by weight of Fe as main alloy components is solution-treated at a temperature of 460°C to 500°C. A method for producing an aluminum alloy material, characterized by performing water or hot water quenching, and natural aging. (2) After solution-treating a molded article obtained from aluminum alloy powder containing 15 to 35% by weight of Si and 0.3 to 9% by weight of Fe as main alloy components at a temperature of 460°C to 500°C. , water or hot water quenching, and further 185
A method for producing an aluminum alloy material, characterized by performing an artificial aging treatment at a temperature below ℃ for a time shorter than that required to obtain maximum hardness.