JPH1096039A - Wear resistant aluminum alloy material excellent in cutting workability and corrosion resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an Al-alloy material for cutting having good corrosion resistance and excellent in wear resistance, by incorporating specified amounts of Si, Fe, Mg and Sn into the Al-alloy material and furthermore adding specified amounts of one or two kinds of Mn and Ti thereto. SOLUTION: The compsn. of an Al alloy material excellent in corrosion resistance, machinability and wear resistance is composed of the one contg., by weight, 3 to 9% Si, 0.02 to 0.5% Fe, 0.5 to 1.5% Mg and 0.1 to 2.0% Sn, furthermore contg. one or two kinds of 0.1 to 1.0% Mn and 0.01 to 1.3% Ti, and the balance Al with inevitable impurities, Si coexists with Mg to precipitate Mg Is grains and to improve its strength. Furthermore, by the eutectic Is phase distribution, its machinability and a wear resistance are improvied. This Al alloy material is obtd., e.g. by subjecting an Al alloy to semi-continuous casting, subjecting the obtd. ingot to homogenizing treatment, thereafter executing extrusion and next subjecting it to aging treatment to form into a T6 refined state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy material which is excellent in machinability and corrosion resistance, does not contain Pb which poses a problem of pollution, and has good wear resistance.

[0002]

2. Description of the Related Art Conventionally, as an aluminum alloy for cutting,
Al-Cu based 2011 alloy, Al-Mg-Si based 6262 alloy and the like are known. However, Pb which is a low melting point metal is added to these alloys in order to improve machinability. In recent years, aluminum alloys containing Pb, which is a toxic substance, have been taken up as a material causing pollution problems and are not suitable for recycling. In particular, in the case of 2011 alloys with poor corrosion resistance, they have been used for a long time in a bad environment. In such a case, there is a possibility that Pb will melt into the outside world and cause a problem.

[0003] Also, 4032 alloy, which is known as a wear-resistant alloy, contains Si, Cu, Ni, etc., and therefore has relatively good machinability.
%, The life of the tool is shortened due to the crystallization of primary Si. For automotive parts, 6061, 6262
In order to obtain the wear resistance of an alloy or the like, it is necessary to take measures such as applying alumite treatment to the surface or protecting the aluminum base with a steel liner. In addition, when cutting is performed on these members, in the case of 6061 alloy, in the case of deep drilling or the like, cutting chips are not discharged well, and the productivity often decreases.

As an aluminum alloy material containing no Pb, having excellent corrosion resistance, relatively low Si content and good wear resistance, Si: 2 to 12%, Fe: 0.1 to 1.0%, Mg: 0.2 to 0% .
8%, Cu: 1-5%, Ti: 0.005-0.2%, Sn: 0.5-
An aluminum alloy material containing 2% or further Mn: 0.2-1.2% and the balance of Al and impurities has been proposed (JP-A-60-190542). When applied, there is a problem that sufficient corrosion resistance cannot be obtained depending on the corrosive environment.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in conventional machinable aluminum alloys and to obtain a cutting aluminum alloy material having good corrosion resistance and excellent wear resistance. The relationship between the alloy composition and the above-mentioned properties was made as a result of experiments and studies from various angles, and the purpose was to maintain corrosion resistance equal to or higher than that of the conventional alloy, and at the same time, after T6 treatment. An object of the present invention is to provide an aluminum alloy material having excellent machinability and wear resistance.

[0006]

The abrasion-resistant aluminum alloy material having excellent machinability and corrosion resistance according to the present invention, which achieves the above objects, has a content of Si: 3 to 9% and Fe: 0.02 to 0.2%.
5%, Mg: 0.5-1.5%, Sn: 0.1-2.0%,
Further, the first feature of the structure is that it contains one or two kinds of Mn: 0.1 to 1.0% and Ti: 0.01 to 0.3%, and the balance is Al and inevitable impurities.

A second feature of the above composition is that it further contains 0.1 to 0.9% of Cu. One or two types of these alloys containing 0.1 to 1.5% Bi and 0.1 to 2.0% Bi are contained in these aluminum alloy materials. , Cr: 0.01-0.3%, Zr: 0.0
1-0.3%, V: 0.01-0.1%, B: 0.08% or less, Sr: 0.005-0.
1%, Sb: 0.01-0.3%, Na: 0.001-0.01%, C
The third, fourth, fifth, and sixth characteristics of a: containing one or more of 0.01 to 0.05% and Ni: containing 0.3 to 0.9%, respectively.

[0008] The significance of the alloy components in the present invention and the reasons for limitation will be described.
₂ Precipitates Si particles and improves strength. Also, eutectic Si
Machinability and wear resistance are improved by the distribution of phases. The preferred content is in the range of 3 to 9%. If the content is less than the lower limit, the effect is small. If the content exceeds the upper limit, coarse primary crystal Si is crystallized and the cutting property, especially the life of the cutting tool is reduced. The more preferable content range of Si is 4.0 to 8.0%.

[0009] Fe is formed of Al-Mn-
Fe (-Si) -based particles are precipitated, and the recrystallized grains are refined to improve machinability. The preferred content is 0.02-0.5%
When the amount is less than the lower limit, the effect is small, and when the amount exceeds the upper limit, coarse crystals of Al-Fe-Si system increase,
Decreases machinability. A more preferable Fe content is 0.1.
It is in the range of 1-0.3%.

[0010] Mg coexists with Si and Cu to increase strength and improve machinability and wear resistance. The preferred content is in the range of 0.5 to 1.5%, with less effect below the lower limit and poor corrosion resistance above the upper limit. Mg
Is more preferably in the range of 0.6 to 1.0%.

Sn functions to improve the machinability.
A preferable content range is 0.1 to 2.0%. If the content is less than the lower limit, the effect is small.
It generates ₂ Sn, strength lowers and also the toughness by the dispersion of the crystallized substance, reducing the corrosion resistance. A more preferred content of Sn is in the range of 0.4 to 1.2%.

Mn makes Al-Mn (-Fe-Si) -based particles precipitate, thereby refining recrystallized grains.
Improves machinability. The preferred content is in the range of 0.1% to 1.0%. If the content is less than the lower limit, the effect is small, and if it exceeds the upper limit, the machinability is impaired. More preferred content of Mn is 0.2
In the range of ~ 0.8%.

Ti precipitates Al-Ti based fine compound particles, refines recrystallized grains, and improves machinability.
The preferred content is in the range of 0.01 to 0.3%. If the content is less than the lower limit, the effect is small. If the content exceeds the upper limit, a coarse intermetallic compound is formed at the time of casting to deteriorate the machinability. A more preferable content range of Ti is 0.03 to 0.15%.

Bi and In improve the machinability by coexistence with Sn. The preferred content range is 0.1 to 1.
If it is less than the lower limit, the effect is small, and if it is more than the upper limit, the low melting point crystallization is excessively dispersed, and the strength, toughness and corrosion resistance are reduced. The more preferable content range of Bi and In is 0.4 to 1.2%.

Cu coexists with Mg to form Al-
Cu-Mg based particles precipitate and increase the strength, machinability,
Improves wear resistance. Preferred content is 0.1-0.9%
When the amount is less than the lower limit, the effect is small, and when the amount exceeds the upper limit, the corrosion resistance is deteriorated. The more preferable content range of Cu is 0.1 to 0.5%.

Cr, Zr, V and B are effective in reducing the size of recrystallized grains, increase the strength of the alloy, and improve the machinability. Preferred contents are Cr: 0.01-0.3%, Zr: 0.0
1 to 0.3%, V: 0.01 to 0.1%, B: 0.08% or less, respectively, the effect is small below the lower limit, and when the content exceeds the upper limit, coarse crystals are formed and the life of the cutting tool is reduced. Lower. A more preferable content range is Cr: 0.05.
-0.20%, Zr: 0.05-0.20%, V: 0.01-0.05%, B:
0.02% or less.

Sr, Sb, Na and Ca refine the eutectic Si phase and improve the machinability and wear resistance. The preferred contents are Sr: 0.005 to 0.1%, Sb: 0.01 to 0.3%, N
a: 0.001 to 0.01%, Ca: 0.01 to 0.05%,
If each is less than the lower limit, the effect is small, and if it exceeds the upper limit, the effect is weak. A more preferable content range is Sr: 0.005.
-0.05%, Sb: 0.05-0.20%, Na: 0.001-0.005
%, Ca: 0.02 to 0.04%.

Ni forms an Al-Ni (-Fe) compound to improve wear resistance and machinability. If the content is less than the lower limit, the effect is small. If the content is more than the upper limit, a coarse compound is formed, which shortens the life of the cutting tool and impairs the extrudability. A more preferred content range of Ni is 0.5 to 0.8%. In addition,
In the aluminum alloy material of the present invention, even if it contains 0.3% or less of Zn, the characteristics are not affected. If Zn exceeds 0.3%, the corrosion resistance tends to decrease.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum alloy material of the present invention
An aluminum alloy having the above composition is cast, for example, by semi-continuous casting, and after the obtained ingot is homogenized, for example, is subjected to extrusion processing, after die quenching in the extrusion step, or after quenching the extruded material, aging treatment. Go to T
6 Refined state. Thereafter, it can be cut and used as a wear-resistant member without conventional alumite treatment or protection by a steel liner.

[0020]

Hereinafter, examples of the present invention will be described in comparison with comparative examples. Example 1 A billet (10 inches in diameter) having the composition shown in Table 1 was subjected to a homogenization treatment, and an extruded rod having a diameter of 60 mm was produced by an indirect extruder. Using the obtained extruded rod, three items of wear resistance, cutability, and corrosion resistance were evaluated according to the following criteria. Table 2 shows the evaluation results.

(1) Abrasion resistance: Ogoshi type abrasion tester
Wear speed 1m / s, wear distance 200m, load 3.2kg, mating material S50C
(HV750), and compared by specific wear. ○: less than 7.0 × 10 ^-7 mm ² / kg △: 7.0 to 10.0 × 10 ^-7 mm ² / kg ×: 10.0 × 10 ^-7 mm ² / kg or more

(2) Machinability: 500 ° C. for 2 hours on the obtained extruded material
, Then water quenching, then 170 ℃ -8h
Was subjected to an artificial aging treatment, and a cutting test was performed. In the cutting test, a hole was drilled in the center of the test piece using a drill, and the cutability was evaluated. The cutting performance was evaluated by measuring the weight per 100 cutting chips (g / 100 chips) and determining the cutting chip discharging property according to the following criteria. In addition, cutting is
Use a straight drill (standard JIS drill, high-speed steel, diameter 20 mm) as a cutting tool, rotation speed 1500 rpm, feed 15
The test was performed at 0 mm / min., Using an emulsion type lubricating oil as the lubricating oil. ◎: less than 20 ○: 20 or more and less than 50 △: 50 or more and less than 100 ×: 100 or more

(3) Corrosion resistance: 50 mm wide x 5 mm thick than extruded material
A sample for evaluation was cut out. 500 on the test material obtained
After the solution treatment at ℃ -2h, water quenching is performed, and 170 ℃ -8h
Was subjected to artificial aging treatment, and the corrosion resistance was evaluated. The corrosion resistance was evaluated based on ASTM B117 for a flat plate having a width of 50 mm, a length of 50 mm and a thickness of 5 mm, and the weight loss after 1000 hours of a salt spray test. ○: 1.0mg / cm ² less than the weight loss △: 1.0 ~2.0mg / cm ² of weight loss ×: 2.0mg / cm ² or more weight loss

The test materials Nos. 1 to 18 according to the present invention have a size of 7.0 × 10
^-7 mm ² / kg less than abrasion, less than 50 g / 100 swarf removal, weight% reduction less than 1.0 mg / cm ² , excellent wear resistance, machinability and corrosion resistance ing.

[0025]

[Table 1]

[0026]

[Table 2]

Comparative Example 1 A billet (diameter 10) of an aluminum alloy having the composition shown in Table 3
mm) was treated in the same manner as in Example 1, and a wear resistance test, a machinability test, and a corrosion resistance test were performed under the same conditions as in Example 1. Table 4 shows the results. In Table 3, those outside the conditions of the present invention are underlined.

[0028]

[Table 3]

[0029]

[Table 4]

As shown in Table 4, the test materials No. 20, No. 24
Is inferior in wear resistance and machinability because Si and Mg are less than the lower limits, respectively. Test materials Nos. 21 to 23 and 26 to 30 are inferior in machinability because Si, Fe, Mn, Ti and Sn are less than the lower limit or more than the upper limit. Test material No. 25 has inferior corrosion resistance because Mg exceeds the upper limit. Test material N
o.31 to 34 are inferior in corrosion resistance because Sn, Cu, Bi, and In each exceed the upper limit. The test material N
o.35 is conventional 2011 alloy, No.36 is 6262 alloy, No.
37 is a 6061 alloy and No. 38 is a 4032 alloy, all of which are out of the components of the present invention, and are therefore inferior in any of abrasion resistance, machinability and corrosion resistance.

[0031]

As described above, according to the present invention, an aluminum alloy material having corrosion resistance equal to or higher than that of a conventional aluminum alloy for cutting, and particularly excellent in machinability after T6 tempering and wear resistance, can be obtained. Offered

Claims (6)

[Claims] 1. Si: 3 to 9% (% by weight, the same applies hereinafter);
Fe: 0.02 to 0.5%, Mg: 0.5 to 1.5%, Sn: 0.1
-2.0%, Mn: 0.1-1.0%, Ti:
A wear-resistant aluminum alloy material having excellent machinability and corrosion resistance, characterized by containing one or two kinds of 0.01 to 0.3% and the balance being Al and unavoidable impurities. 2. Si: 3 to 9%, Fe: 0.02 to 0.5%,
Mg: 0.5 to 1.5%, Sn: 0.1 to 2.0%, Cu: 0.1
0.9%, Mn: 0.1-1.0%, Ti:
A wear-resistant aluminum alloy material having excellent machinability and corrosion resistance, characterized by containing one or two kinds of 0.01 to 0.3% and the balance being Al and unavoidable impurities. 3. The method according to claim 1, wherein the aluminum alloy material further contains Bi: 0.
3. A wear-resistant aluminum alloy material having excellent machinability and corrosion resistance according to claim 1, which contains one or two of 1-1.5% and In: 0.1-2.0%. 4. The aluminum alloy material further comprises Cr: 0.4.
01-0.3%, Zr: 0.01-0.3%, V: 0.01-0.1%,
B: A wear-resistant aluminum alloy material having excellent machinability and corrosion resistance according to claim 1, which contains one or more of 0.08% or less. 5. The method according to claim 1, wherein the aluminum alloy material further comprises Sr: 0.5.
005 to 0.1%, Sb: 0.01 to 0.3%, Na: 0.001 to 0.0
The wear-resistant aluminum alloy material having excellent machinability and corrosion resistance according to any one of claims 1 to 4, comprising one or more of 1% and Ca: 0.01 to 0.05%. 6. An aluminum alloy material further comprising Ni: 0.3
The wear-resistant aluminum alloy material having excellent machinability and corrosion resistance according to any one of claims 1 to 5, characterized in that the aluminum alloy material contains 0.1 to 0.9%.