JPS63183159A - Manufacture of expanded material of wear-resistant free-cutting aluminum alloy - Google Patents

Abstract

PURPOSE:To manufacture the titled expanded material without adding free- cutting components of low-m.p. metals, by subjecting an Al-Si alloy with a specific composition to soaking treatment, extrusion, solution heat treatment, and cold drawing, in succession, under specific conditions. CONSTITUTION:An ingot of an Al alloy consisting of, by weight, 6-14% Si, 0.1-1.0% Fe, 1.0-3.0% Cu, 0.05-0.2% Mn, 0.2-1.5% Mn, 0.05-0.5% Cr, 0.05-1.0% Ni, and the balance Al is prepared. This ingot is successively subjected to soaking treatment at 450-520 deg.C for >=4hr, extrusion at 300-500 deg.C, solution heat treatment at 470-525 deg.C, and cold drawing at 3-30% draft. In this way, a wear-resistant Al alloy combining superior machined-surface roughness with corrosion resistance, further improved in chip treatability, and excellent in machinability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a wrought aluminum alloy material having wear resistance and excellent machinability.

[Conventional technology]

Conventionally, various He1 alloys have been used in VTR parts to reduce weight, and wear-resistant A, e-s; series alloys have been used especially for tape sliding parts such as cylinders. ing. By the way, with recent advances in VTR equipment,
In addition to conventional models, consideration is being given to transitioning to lighter, smaller, and higher performance models such as the 8-movie type, and there is a need to improve the characteristics of AJt alloy materials for such applications. For the above-mentioned parts whose final shape is obtained by cutting, it is becoming important to use Al alloy materials for wear resistance and good machinability.

(Problems to be Solved by the Invention) The above Al-3i alloy is JIS 4032 (S
i 11.0~13.5%, Cu0.50~1.3%
, Mg0.8-1.3%, Nio, 5-1.3%, balance Ai) is used as a typical alloy, but although this alloy has relatively good wear resistance, it has poor machinability, especially machinability. Poor powder processing properties. In other words, the chips do not become fine, become ribbon-like or spiral-shaped, and are difficult to fall off, so they accumulate between the workpiece and the cutting tool, causing damage to the workpiece and significantly deteriorating the surface roughness of the finished surface. arise.

In order to improve the machinability of the above Al alloy, conventional Aj
! Pb based on -3i alloy.

A method of adding low melting point metals such as 3n and 3i is known. This is because A, the low melting point metal that is dispersed in a spherical shape without forming a solid solution in the f2 alloy easily softens due to the processing stress applied to the workpiece during machining and the processing heat generated between the workpiece and the cutting tool. break.

Therefore, the chips are not continuous, but are divided into fine particles, so they easily fall off and do not damage the workpiece. However, the low melting point metal itself is easily corroded, and the exposed low melting point metal particles on the cut surface leave minute irregularities on the cut surface. For this reason, a new problem arises in that an Al alloy to which a low melting point metal is added is inferior in corrosion resistance and surface roughness of the cut surface, compared to an Al alloy having the same alloy composition but without the addition of a low melting point metal.

[Means for solving problems]

In view of this, the present invention has conducted various studies and found that Pb causes deterioration in corrosion resistance and surface roughness of the cut surface.

A method for manufacturing a wear-resistant aluminum alloy wrought material with improved machinability without adding free-cutting components such as low melting point metals such as Sn and Bi has been developed.

That is, one of the manufacturing methods of the present invention is Si6 to 14 wt%.

Fe0.1-1.0wt%, Cuo,i ~3.0
wt%.

Mn0.05-0.2 wt%, Mgo, 2-1.
5 wt%.

Cro, 05-0.5 wt%, N! 0.05～
1. An aluminum alloy ingot containing OWi% and the balance Al and normal impurities is subjected to soaking treatment at a temperature of 450 to 520 °C for 4 hours or more, then extrusion processing at a temperature of 300 to 500 °C, and then 470 °C It is characterized in that it is subjected to solution treatment at a temperature of ~525°C, followed by cold drawing at a processing rate of 3 to 30%.

Another method of the present invention is Si6 to 14 wt%,
Feo, 1-1.0wt%, Cu0.1-3.0w
t%, Mn0.05-0.2 wt%, Mg0.2
~1.5 wt%, Cro, 05~0.5 wt%,
An aluminum alloy ingot containing 0.05 to 1.0 wt% of Ni and the balance being Al and normal impurities was
After soaking for 4 hours or more at a temperature of 20℃,
Extrusion processing is performed at a temperature of 0 to 500°C, and then 470 to 500°C.
Solution treatment was performed at a temperature of 525°C, and then the processing rate was 3.
It is characterized by applying cold drawing of ~30% and then artificial aging treatment at a temperature of 150 to 200°C for 6 to 12 hours.

[For production]

The reason why the aluminum alloy composition is limited as described above in the present invention is as follows. In the present invention, 3i and l'V1g
A Mgz3i compound is formed by forming a Mgz3i compound to increase the strength, and 3i is added in excess of Si required to form a MgzSi compound to form a eutectic 3i, improving wear resistance. Content 6-14w
The reason why it is limited to t% (hereinafter simply abbreviated as %) is that if it is less than 6%, wear resistance will be insufficient, and if it exceeds 14%, cold workability and cutting will be deteriorated. The purpose of adding Fe is to improve wear resistance.The Fe content is 0.1 to 1.0%.
The reason for this limitation is that if it is less than 0.1%, the above effect will not be observed, and if it exceeds 1.0%, the corrosion resistance will be reduced.

The addition of Cu has the effect of increasing the strength of the base, and the eutectic 3i
The content of CU is limited to 1.0 to 3.0% because the above effect cannot be obtained sufficiently if it is less than 1.0%. This is because if it exceeds %, cold workability will be reduced. The purpose of adding Mn and Cr is to improve wear resistance, and the Mn content is set to 0.0.
The reason why the content of Cr is limited to 0.05 to 0.5% is that if the content is less than 0.05%, the above effects are insufficient, and if the content of Mn is 0.2% or Cr is 0. This is because if it exceeds .5%, hot and cold workability will deteriorate.

The reason for adding Mg is to form a Mgz Si compound with 3i as described above to increase strength, and if it exceeds 1.5%, it reduces cold workability. The purpose of adding Ni is to maintain wear resistance when the temperature rises.
The content of i was limited to 0.05 to 1.0% due to 0.0
This is because if it is less than 5%, the above effect will be small, and if it exceeds 1.0%, the above effect will be saturated.

Next, the above Al alloy ingot is subjected to soaking treatment in the same way as general extrusion billets, to make the micro-segregation of the ingot uniform, remove thermal strain and improve extrudability, and further to make the eutectic Si spheroidal. This is to improve wear resistance and machinability.

However, the soaking temperature was limited to 450 to 520°C because the above effects are insufficient at temperatures below 450°C.
At temperatures above 0°C, local melting of the Al alloy ingot occurs.

This is to cause melting. The reason why the soaking time was set to 4 hours or more is because the eutectic 3i is insufficiently spheroidized if it is less than 4 hours. Note that it is desirable to perform the soaking treatment for as long as possible, for 4 hours or more, in order to improve machinability and wear resistance. The reason why the ingot after soaking treatment is extruded at a temperature of 300 to 500°C is that at temperatures below 300°C, the extrudability of the Al alloy ingot with the above components according to the present invention is extremely poor.
This is because, if the temperature exceeds 100, the extrusion causes local melting of the Al alloy and deteriorates the surface of the extruded material. After that, the temperature of the solution treatment applied to the extruded material was limited to 470 to 525°C because at temperatures below 470°C, solution treatment is insufficient, and at temperatures above 525°C, local melting of the Al alloy occurs. It is. The purpose of cold drawing after solution treatment is to accumulate processing strain inside the Al alloy, and some of this processing strain forms slip lines in the Al alloy, but most of the rest forms non-plastic eutectic 3i particles. Many small voids are formed around the . Therefore, when cutting this drawn material, the presence of such voids causes chips to be broken up by the voids, making the chips fine and improving machinability, especially chip disposal. In this case, the processing rate of cold drawing is 3 to 30%.
The reason for this is that if the processing rate is less than 3%, the amount of strain is insufficient to form microvoids and the effect of making chips finer cannot be obtained.If the processing rate is more than 30%, cold drawing This is because the material sometimes breaks, making it impossible to manufacture.

Next, after cold drawing, artificial aging treatment is performed to improve the wear resistance by increasing the hardness and mechanical properties of the material. The reason for limiting the time is that treatment at a temperature of less than 150℃ for less than 6 hours has no effect because aging hardly progresses, whereas treatment at a temperature of over 200℃ for more than 12 hours causes overaging and results in no effect. This is because the abrasion resistance is reduced. In addition, in order to obtain good wear resistance and machinability of the Al alloy, it is effective to refine the eutectic 3i by adding a small amount of Na, 3b, 3r, etc. during casting, as is commonly used.

〔Example〕

Next, embodiments of the present invention will be described in detail.

Al alloys with the nine types of compositions shown in Table 1 were melted and cast according to conventional methods, and the resulting ingots were subjected to the treatments shown in Table 2, then cold-drawn bars were made, and these were used as test materials. Machinability,
The following evaluation tests were conducted for cut surface roughness, wear resistance, and corrosion resistance, and the results are compared with T6 treated material, which was subjected to conventional solution treatment followed by artificial aging treatment, as shown in Table 2. Shown below.

Machinability is achieved with a cutting speed of 300m/mi using a carbide tool.
n, depth of cut 0.2m and feed rate 0.025-0.1
Evaluation was made based on the weight per 100 chips when cutting was performed under cutting conditions of 1M1/rev without using cutting oil. The roughness of the cut surface was evaluated using the maximum surface roughness Rmax of a mirror-finished surface using a diamond cutting tool. Abrasion resistance was evaluated using a mirror-finished test material by weight change during a 1000-hour running test using a VTR magnetic tape. Corrosion resistance was evaluated by weight change during 500 hours of salt spray test.

The results for each test item and their overall evaluation are classified into three categories as shown below and are listed in Table 2.

◎: Good for all test items.

Δ: Inferior in any test item.

X: Significantly inferior in one or more test items.

As is clear from Tables 1 and 2, the cold drawn bars (Nα1 to Nα7) produced by the method of the present invention show excellent values in all test items. -6 Comparative material (Nα8.
Nα9) has poor chip disposal properties during cutting.

In addition, comparative alloys (Nα10 and Nα11) in which a low melting point metal that does not dissolve in Al is dispersed in the matrix have significantly inferior cut surface roughness and corrosion resistance, and are significantly inferior to conventional alloys (J
It can be seen that the conventional materials (Nα12 and Nα13) obtained by processing the compositions corresponding to IS 221B and JIS 4032 using conventional methods are significantly inferior in machinability, corrosion resistance, and wear resistance.

(Effects of the Invention) As described above, according to the present invention, it is possible to provide a wear-resistant aluminum alloy that has good cutting surface roughness and corrosion resistance, and further improves the processing properties of cutting chips and has excellent machinability. It has remarkable industrial effects, such as being widely applicable to parts and products whose final shape is obtained only by cutting.

Claims (2)

[Claims] (1) Si6-14wt%, Fe0.1-1.0wt%
, Cu1.0~3.0wt%, Mn0.05~0.2w
t%, Mg0.2-1.5wt%, Cr0.05-0.
5wt%, Ni0.05-1.0wt%, the balance A
45 aluminum alloy ingots consisting of l and normal impurities
After performing soaking treatment at a temperature of 0 to 520°C for 4 hours or more, extrusion processing was performed at a temperature of 300 to 500°C, and then 4 hours.
A method for producing a free-cutting, wear-resistant aluminum alloy wrought material, which comprises subjecting the material to solution treatment at a temperature of 70 to 525°C, followed by cold drawing at a processing rate of 3 to 30%. (2) Si6-14wt%, Fe0.1-1.0wt%
, Cu1.0~3.0wt%, Mn0.05~0.2w
t%, Mg0.2-1.5wt%, Cr0.05-0.
5wt%, Ni0.05-1.0wt%, the balance A
45 aluminum alloy ingots consisting of l and normal impurities
After performing soaking treatment at a temperature of 0 to 520°C for 4 hours or more, extrusion processing was performed at a temperature of 300 to 500°C, and then 4 hours.
Solution treatment is performed at a temperature of 70 to 525°C, and then cold drawing is performed at a processing rate of 3 to 30%.
A method for producing a free-cutting, wear-resistant wrought aluminum alloy material, which comprises performing an artificial aging treatment at a temperature of 0° C. for 6 to 12 hours.