JP2008266719A - Extruded material of free-cutting aluminum alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extruded material of free-cutting aluminum alloy in which chip breakability can be improved without addition of low-melting-point metals including Pb and which has excellent productivity. <P>SOLUTION: The extruded material of free-cutting aluminum alloy has a composition consisting of, by mass, 1.0 to 1.5% Si, 0.8 to 1.5% Fe, 0.6 to 1.0% Mg, 0.2 to 0.5% Cu, 0.05 to 0.8% Mn, 0.05 to 0.8% Ni and the balance aluminum with inevitable impurities. By using this material, strength can be improved by Si, Mg, Cu and Fe as its components and also chip breakability can be improved by the crystallization of intermetallic compounds of Si, Mg, Cu and Fe. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a free-cutting aluminum alloy extruded material.

In cutting an aluminum alloy, the chip breaking property is regarded as important, and it is desirable that the chip is finely cut.
Conventionally, as an aluminum alloy excellent in machinability, extruded materials such as JIS2011 alloy in which Pb and Bi are added to an Al—Cu alloy and JIS6262 alloy in which Pb and Bi are added to an Al—Mg—Si alloy are used. It has been. However, due to recent environmental problems, an aluminum alloy excellent in machinability without adding Pb has been required.

Therefore, an Sn—Bi-added alloy not containing Pb has been proposed as an alternative to the JIS 6262 alloy, and a free-cutting aluminum alloy having almost the same performance as the JIS 6262 alloy in terms of machinability and corrosion resistance is being distributed.

  However, the Sn-added free-cutting aluminum alloy has a problem of high-temperature embrittlement as compared with the conventional alloy and a problem that dissolution occurs when it comes into contact with an alcohol solution containing one or more OH groups at 120 ° C.

  Patent Document 1 contains Si: 1.5 to 12.0 mass%, Mg: 0.5 to 6.0 mass%, and Ti: 0.01 to 0.1 mass%, respectively. Mn: 0.5 to 2.0 mass% or Cu: 0.1 to 1.0 mass%, or both, Fe: 0.5 to 1.0 mass%, Cr: 0.1 An aluminum alloy containing at least one of ˜0.5 mass% and Zr: 0.1 to 0.5 mass% has been disclosed.

Japanese Patent Application Laid-Open No. 09-249931

    However, although the aluminum alloy disclosed in Patent Document 1 is excellent in machinability, since the Si content is as high as 1.5 to 12.0%, the improvement in machinability is sufficient due to the improvement in wear resistance. It wasn't.

  An object of the present invention is to provide a free-cutting aluminum alloy extruded material having a good chip breaking property without adding a low-melting-point metal such as Pb in view of the above-described problems of the prior art.

  That is, the free-cutting aluminum alloy extruded material of the present invention has Si: 1.0 to 1.5 mass% (hereinafter,%), Fe: 0.8 to 1.5%, Mg: 0.6 to 1.0%, Cu: 0.2 to 0.5% is contained, and the balance is made of aluminum and inevitable impurities.

  Further, the free-cutting aluminum alloy extruded material of the present invention has Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg: 0.6 to 1.0%, Cu: 0.2 -0.5%, Mn: 0.05-0.8%, The remainder consists of aluminum and an unavoidable impurity, It is characterized by the above-mentioned.

  Furthermore, the free-cutting aluminum alloy extruded material of the present invention has Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg: 0.6 to 1.0%, Cu: 0.2 -0.5%, Ni: 0.05-0.8% is contained, and the balance consists of aluminum and inevitable impurities.

  In addition, the free-cutting aluminum alloy extruded material of the present invention has Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg: 0.6 to 1.0%, Cu: 0.00. It contains 2 to 0.5%, Mn: 0.05 to 0.8%, Ni: 0.05 to 0.8%, and the balance is made of aluminum and inevitable impurities.

[Action]
According to the free-cutting aluminum alloy extruded material of the present invention, the chip breaking property is improved by the strength improvement by the components Si, Mg, Cu, Fe and the crystallization of the metal tube compound of Si, Mg, Cu, Fe. The

  The free-cutting aluminum alloy extruded material according to the present invention is an Al-Mg-Si-based alloy, and drilling that is almost equivalent to a conventional free-cutting alloy, for example, JIS 6262 alloy, without adding a low melting point metal such as Pb. Sex can be obtained. Further, the low melting point metal may delay the growth of the anodic oxide film, and when the anodic oxide film is applied to an alloy containing these low melting point metals, the film may be peeled off at a high temperature due to melting of the low melting point metal. The free-cutting aluminum alloy extruded material of the present invention that does not contain a low-melting-point metal also exhibits an effect that the soundness of the anodized film is maintained.

The reason for limitation of each component of the free-cutting aluminum alloy extruded material of the present invention will be described below.
Si, Mg:
Si forms Mg ₂ Si together with Mg and contributes to the strength. Below the lower limit, these effects are poor, and when the upper limit is exceeded, the extrudability decreases. Moreover, Si addition forms an Al-Fe-Si type compound with Fe, and contributes to chip parting property.

Fe:
Fe forms a compound such as an Al—Fe system and improves the chip breaking property. If it is less than the lower limit, the effect is poor, and if it exceeds the upper limit, the extrudability decreases. Moreover, an Al-Fe-Si-based compound is formed together with Si, contributing to chip breaking property.

Cu:
Cu contributes to strength by heat treatment. Below the lower limit, the effect is poor. Exceeding the upper limit deteriorates extrudability.

Mn:
It is preferable to add Mn because it dissolves by heat treatment and contributes to improving the strength and promotes the effect of cutting chips. When added, the content is 0.05% or more, but if the upper limit (0.8%) is exceeded, the extrudability is lowered. Moreover, the Al-Mn-Fe type compound by addition of Mn is expected to improve the chip breaking property.

Ni:
Ni improves heat resistance. In particular, wear-resistant alloys and the like are generally added with Ni in order to improve heat resistance, and it is more preferable to add this alloy in order to cope with various applications. In addition, Ni addition can be expected to improve chip breaking by making a compound. In order to obtain these effects, it is preferable to add 0.05% or more of Ni. More preferably, it is 0.2% or more. In addition, when it exceeds an upper limit (0.8%), toughness, such as a fall of elongation, will be reduced.

Ti, B, Cr, Zr:
Ti and B are added as an ingot refining agent, and one or two of them are added as necessary. When added, Ti is 0.01 to 0.05%, and B is 0.001 to 0.05%. If it is less than the lower limit, the effect cannot be sufficiently obtained, and even if the upper limit is exceeded, the effect is not further improved. Cr and Zr are added together with Mn as necessary to refine the recrystallized grains and improve the strength. However, adding too much makes the extrudability deteriorated and the quenching sensitivity becomes sensitive. The following is desirable.

  The method for producing the free-cutting aluminum alloy extruded material of the present invention is not particularly limited, and may be produced according to a conventional method. For example, it may be melted and cast by a normal method, and after performing a homogenization treatment as necessary, extrusion may be performed. Further, the processing and tempering after the extrusion are not particularly limited, and the tempering may be selected according to the application under normal production conditions. For example, T1 as it is after hot extrusion may be used, T4 may be subjected to solution treatment (for example, 520 to 550 ° C. × 1 hr), or solution / artificial aging (for example, 170 to 180 ° C. × 8 hr) may be performed. T6 may be used.

Next, based on an Example, this invention is demonstrated in detail.
An alloy having a composition shown in Table 1 was melted to obtain an ingot having a diameter of 220 mm. This ingot was subjected to a homogenization treatment at 500 ° C. × 6 hr, and then a φ35 round bar was obtained by hot extrusion. The solution was quenched at 530 ° C. for 1 hour and then immediately cooled with water, and further subjected to artificial aging treatment at 180 ° C. for 8 hours.

A cutting test using a Nazitaper shank drill was performed using the test alloy extruded material thus obtained. Cutting conditions were as follows: rotational speed: 2000 rpm, feed: 50 mm / min, no lubrication.
Photographs of chips generated during drilling for each test alloy extruded material are shown in FIGS. Since drilling changes the shape of the chips depending on the cutting depth, the drilling workability of the drilling shapes shown in FIGS.

  In the comparative study, each test alloy extruded material (No. 1 to No. 10) corresponding to the example alloy of the present invention and each test alloy extruded material (No. 11) which is a comparative example alloy not satisfying the conditions of the present invention. To No. 23), each test alloy extruded material (No. 24, No. 25) which is a typical 6000 series structural aluminum alloy, and further corresponds to a free-cutting aluminum alloy using a conventional low melting point metal. Each test alloy extruded material (No. 26, No. 27) is observed with a photograph of each chip, and is distinguished from A to B, C in order from the superiority of the chip shape, evaluation A, evaluation B or more Qualified.

Evaluation A shows a state in which even if there is a chip connected in a spiral shape, the chip is divided as a whole, and a chip entangled with the drill is not seen.
Evaluation B is a state in which there is no continuous swarf and the swarf is divided, and a somewhat longer swarf is spirally discharged and the swarf is not entangled with the drill.
Evaluation C shows that although there are some finely divided chips, there is a beard-like chip that has been very long and entangled with the drill.
Since each test alloy had intermediate chips A to C, for example, the intermediate between A and B is expressed as “AB”, and the intermediate between B and C is “BC”. Evaluation AB was eligible and Evaluation BC was disqualified.

Table 1 shows the components and evaluation results of each test alloy extruded material in the above cutting test.

Example Alloy No. 1 contains Si 1.19%, Fe 1.23%, Cu 0.28%, Mg 0.78%, Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg: 0 .6 to 1.0% and Cu: 0.2 to 0.5% were satisfied and the evaluation was B. That is, as shown in FIG. 1, there was no continuous swarf, and the swarf was in a state of being divided. The slightly longer swarf was spirally discharged and the swarf was not entangled with the drill.
Example Alloy No. 2 is an AB evaluation satisfying the condition of including Si 1.21%, Fe 1.19%, Cu 0.26%, Mn 0.24%, Mg 0.78% and Mn: 0.01 to 0.8%. It was. That is, it was in a better state than the state shown in FIG.

    Example Alloy No. 3 contains Si 1.00%, Fe 1.24%, Cu 0.29%, Mg 0.62%. 4 contains 1.50% Si, 1.00% Fe, 0.28% Cu, and 0.81% Mg. 5 contains Si 1.15%, Fe 1.04%, Cu 0.28%, Mg 0.83%, Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg : 0.6-1.0%, Cu: 0.2-0.5% was satisfied, and B evaluation was obtained.

    Example Alloy No. 6 contains Si 1.16%, Fe 1.04%, Cu 0.27%, Mn 0.78%, Mg 0.79%. 7 contains Si 1.49%, Fe 0.99%, Cu 0.27%, Mn 0.76%, Mg 0.84%, satisfying the conditions of Mn: 0.01 to 0.8%, respectively, and AB evaluation there were.

Example Alloy No. 8 contains Si 1.26%, Fe 1.15%, Cu 0.27%, Mn 0.01, Mg 0.80% and Ni 0.19%, Mn: 0.01 to 0.8%, Ni: 0 It was AB evaluation satisfying the condition of 0.05-0.8%.
Example Alloy No. No. 9 contains Si 1.38%, Fe 1.25%, Cu 0.30%, Mg 0.80% and Ni 0.21% and satisfies Ni: 0.05 to 0.8%. Met.
Further, Example Alloy No. 10 contains Si 1.29%, Fe 1.10%, Cu 0.34%, Mn 0.50%, Mg 0.83% and Ni 0.47%, Mn: 0.01 to 0.8%, Ni : The condition of 0.05 to 0.8% was satisfied, and the evaluation was AB.
As described above, all of the alloys according to the embodiments of the present invention have no continuous chips as shown in FIG. 1 and are in a state where the chips are divided. The slightly longer chips are spirally discharged and cut into a drill. It was more than B evaluation which is a state which a powder does not get entangled.

Comparative Example No. 11 contains Si 0.52%, Fe 1.25%, Cu 0.28%, Mg 0.79% and Ni 0.51%, and the Ni content is 0.05 to 0.8% with respect to the amount of Ni. Although satisfied, the Si content was 0.52%, the condition of Si: 1.0 to 1.5% was not reached, and the BC evaluation was made. That is, although it was better than the state of C evaluation shown in FIG. 2, it was not as good as the state shown in FIG.
Comparative Example No. 12 contains Si 1.72%, Fe 0.41%, Cu 0.28%, Mn 0.82%, Mg 0.83%, Fe content is 0.41%, Fe: 0.8-1. The condition of 5% was not reached, and the Mn content was 0.82%, and the Mn content was Mn: 0.05 to 0.8%.

Comparative Example No. 13 contains Si 0.47%, Fe 1.25%, Cu 0.30%, Mg 0.8%, Si content is 0.47%, and Si: 1.0 to 1.5% It was not achieved and was a BC evaluation.
Comparative Example No. 14 contains Si 0.45%, Fe 1.3%, Cu 0.28%, Mn 0.28%, Mg 0.8%, Si content is 0.45%, Si: 1.0-1.5 % Was not reached and the BC was evaluated.
Comparative Example No. 15 contains Si 2.30%, Fe 0.70%, Cu 0.20%, Mg 0.75%, Si content is 2.30%, and Si: 1.0 to 1.5%. In addition, the Fe content was 0.70%, the condition of Fe: 0.8 to 1.5% was not reached, and the evaluation was BC.

Comparative Example No. 16 contains Si 0.85%, Fe 0.90%, Cu 0.29%, Mg 0.54%, the Si content is 0.85%, and Si: 1.0 to 1.5% In addition, the content of Mg was 0.54%, and the condition of Mg: 0.6 to 1.0% was not reached, which was a BC evaluation.
Comparative Example No. 17 contains Si 1.53%, Fe 1.30%, Cu 0.58%, Mg 0.69%, the Cu content is 0.58%, and Cu: 0.2 to 0.5%. The BC rating was exceeded.

Comparative Example No. 18 contains Si 1.00%, Fe 0.85%, Cu 0.18%, Mg 0.65%, Cu content is 0.18%, and Cu: 0.2 to 0.5% The BC evaluation was not achieved.
Comparative Example No. 19 contained Si 1.20%, Fe 0.88%, Cu 0.25%, and Mg 0.55%, and the Mg content was Mg: 0.6 to 1.0%. .

Comparative Example No. 20 contains Si 1.20%, Fe 0.34%, Cu 0.30%, Mg 0.88%, Fe content is 0.34%, Fe: 0.8 to 1.5% It was C evaluation without reaching.
Comparative Example No. 21 contains Si 1.19%, Fe 0.39%, Cu 0.28%, Mn 0.82%, Mg 0.82%, Mn: 0.82% exceeding the condition of 0.05-0.8% It contained Mn, and the Fe content was 0.39%, and the C was evaluated without reaching the condition of Fe: 0.8 to 1.5%.

Comparative Example No. 22 contains Si 1.76%, Fe 0.43%, Cu 0.28%, Mn 0.01%, Mg 0.81%, Fe content is 0.43%, Fe: 0.8-1.5 It was C evaluation without reaching the condition of%.
Comparative Example No. 23 contains Si 0.50%, Fe 0.82%, Cu 0.25%, Mg 0.65% and Ni 0.28%, Si content is 0.50%, Si: 1.0 It was C evaluation without reaching the condition of ˜1.5%. That is, although there were some finely divided chips, there were beard-like chips that continued for a very long time, and were entangled with the drill.

That is, the comparative alloy No. 11-No. No. 19 was inferior in chip breaking property and was evaluated by BC because the amount of any of Si, Fe, Mg, Mn, or Ni that mainly contributed to chip breaking property was less than the specified range of the present invention.
Further, comparative alloy No. 1 in which the addition amount of Fe, Si, Mg was particularly small. 20-No. No. 22 was further inferior to chip breaking property and was C evaluation.
In addition, comparative alloy No. 18, no. In No. 23, Mg and Cu were less than the specified range of the present invention, so that sufficient strength could not be obtained.
Comparative Example Alloy No. Mn whose Mn exceeded the specified range of the present invention 12 and no. 21, Comparative Alloy No. 1 in which Si exceeded the specified range of the present invention. About 15, it was inferior to extrudability.

  No. 24 JIS6063 alloy contains Si 0.48%, Fe 0.20%, Cu 0.02%, Mn 0.15%, Mg 0.53%, Si: 1.0 to 1.5%, Fe: 0.8 -1.5%, Mg: 0.6-1.0%, Cu: 0.2-0.5%, Mn: 0.05-0.8%, Ni: 0.05-0.8% It was C evaluation without reaching any conditions. FIG. 2 shows the state of chips of the 6063 alloy. As shown in FIG. 2, although there were some finely divided chips, there was a beard-like chip that was very long and entangled with the drill.

  No. 25 JIS6061 alloy contains Si 0.69%, Fe 0.26%, Cu 0.30%, Mn 0.12%, Mg 1.01%, Si: 1.0-1.5%, Fe: 0.8- 1.5%, Mn: 0.05% to 0.8%, Ni: 0.05% to 0.8%, and Mg: 0.6% to 1.0% It was C evaluation. That is, it was the state similar to the state of the chip of 6063 alloy shown in FIG.

    No. 26 JIS6262 alloy contains Si 0.56%, Fe 0.21%, Cu 0.29%, Mn 0.03%, Mg 0.93%, Si: 1.0-1.5%, Fe: 0.8- Neither 1.5%, Mn: 0.05 to 0.8%, Ni: 0.05 to 0.8%, but Pb: 0.51% and Bi: 0.46% It was A evaluation. FIG. 3 shows the state of chips of 6262 alloy which is this well-known Pb—Bi-added free cutting alloy. As shown in FIG. 3, although there were chips connected in a spiral shape, the chips were divided as a whole, and no chips entangled with the drill were found.

    No. 27 Sn, Bi addition alloy contains Si 0.73%, Fe 0.09%, Cu 0.33%, Mn 0.00%, Mg 0.84%, Si: 1.0-1.5%, Fe: 0 .8 to 1.5%, Mn: 0.05 to 0.8%, Ni: 0.05 to 0.8%, but none of Sn: 0.72% and Bi: 0. It was A evaluation containing 86%.

However, the conventional free-cutting aluminum alloy No. No. 26 is not preferable because it contains harmful Pb. In addition, No. which is a conventional free-cutting aluminum alloy. No. 27 contains Sn, so there are concerns about problems of high temperature embrittlement and dissolution in an alcohol solution. Furthermore, no. In 26 and 27, Pb, Bi, and Sn: low melting point metals not only delay the growth of the anodic oxide film, but when the anodic oxide film is applied, the film may peel off at a high temperature due to melting of the low melting point metal. The soundness of the anodized film may be impaired.

The photograph of the chip generated at the time of the machinability test of the example alloy of the present invention. The photograph of the chip | tip which generate | occur | produced by performing the machinability test of 6063 alloy in order to contrast with the Example alloy of this invention. The photograph of the chip | tip which generate | occur | produced by performing the machinability test of the JIS6262Pb-Bi addition free-cutting alloy for contrast with the Example alloy of this invention.

Claims (4)

Si: 1.0-1.5 mass% (hereinafter%), Fe: 0.8-1.5%, Mg: 0.6-1.0%, Cu: 0.2-0.5% A free-cutting aluminum alloy extruded material, wherein the balance is made of aluminum and inevitable impurities. Si: 1.0 to 1.5%, Fe: 0.8 to 1.5%, Mg: 0.6 to 1.0%, Cu: 0.2 to 0.5%, Mn: 0.01 to A free-cutting aluminum alloy extruded material containing 0.8%, the balance being made of aluminum and inevitable impurities. Si: 1.0-1.5%, Fe: 0.8-1.5%, Mg: 0.6-1.0%, Cu: 0.2-0.5%, Ni: 0.05- A free-cutting aluminum alloy extruded material containing 0.8%, the balance being made of aluminum and inevitable impurities. Si: 1.0-1.5%, Fe: 0.8-1.5%, Mg: 0.6-1.0%, Cu: 0.2-0.5%, Mn: 0.01- A free-cutting aluminum alloy extruded material containing 0.8%, Ni: 0.05 to 0.8%, the balance being made of aluminum and inevitable impurities.