JPH01281803A - Cutting tool for aluminium alloy - Google Patents

Abstract

PURPOSE:To reduce any wear of a tool while avoiding generation of chipping so as to get a fine cutting finish surface, by setting a rake angle and a nose radius to 6 to 30 deg. and 0.2mm or more respectively among tip shape factors, in a diamond cutting tool. CONSTITUTION:Among factors of the tip shape of a diamond tool, when a rake angle is less than 5 deg., flank wear increases, and with an increase in the wear, a cutting resistance increases and finished surface is made more rough. On the other hand, when the rake angle is more than 30 deg., there is such a tendency that chipping is easy to happen instead. Making a nose round serves to prevent chipping, but when the radius of the nose is less than 0.2mm it is same as the case of giving no roundness, and when more than 1.0mm, the cutting resistance increases. Therefore, by setting the rake angle to 5-30 deg., the radius of the nose 0.2mm or more, the tool wear and the cutting resistance can be reduced while avoiding generation of chipping, a cut and finished surface excellent in its flatness can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is suitable for cutting aluminum alloys (including aluminum matrix composite materials such as MMC and FRM), particularly hypereutectic AΩ-31 alloys or dispersion-strengthened aluminum matrix composites. This invention relates to a diamond cutting tool for cutting materials.

2. Description of the Related Art As cutting tools for hypereutectic AΩ-81 alloy containing hard 81 particles, diamond cutting tools using diamond or a sintered body thereof as the material are often used.

Generally, commercially available diamond cutting tools used for conventional purposes have rake angles of -π/36 (-5") or π/36 (5") in their cutting edge shapes.
) and had a non-rounded nose. Of course, the performance of such a cutting tool is that it does not easily cause chipping, chipping, etc., but it also has as little wear on the flank as possible, has low cutting resistance, and has a low surface roughness on the finished surface. There is a need for excellence in comprehensive evaluation of things such as what can be done, etc., but in the past, sufficient research has not yet been done on the shape specifications of the cutting edge of diamond cutting tools to meet these demands. The reality is that there was no such thing.

Problems to be Solved by the Invention Conventionally, in cemented carbide cutting tools, hypereutectic AQ-Si
When cutting alloys, the rake angle of the cutting edge should be set to π/9 (2
It has been reported that tool wear can be reduced and the life of the tool can be extended by setting it as large as 0') to π/6 (30'').

On the other hand, in the case of diamond cutting tools, π/3
It is known that if the rake angle is set to a large value exceeding 6, chipping will occur and the rake angle will become unusable.To avoid this, a film with a negative rake angle is often used in the film. The reality is that

However, the conventional diamond cutting tools with small rake angles as described above are still not fully satisfactory in terms of tool life, and furthermore, the cutting force is large, and the surface roughness of the cut surface is low. However, it was not always completely satisfactory, and further improvements were desired.

An object of the present invention is to provide a diamond cutting tool for A2 alloy that meets the above-mentioned request for improvement.

Means for Solving the Problems As a result of many experiments in which diamond cutting tools with different cutting edge specifications were produced for the above-mentioned purpose, this invention was developed to reduce the stress on the tip of the cutting edge by rounding the nose. By reducing concentration and reducing the occurrence of chipping, and by setting a large rake angle, tool wear is reduced, its durability is increased, cutting force is also reduced, and the surface roughness of the finished surface is small. By discovering toshi scales, he was able to complete this invention.

That is, the present invention is characterized in that, in a diamond cutting tool made of diamond or a sintered body thereof, the shape specifications of the cutting edge include the following settings: rake angle = 5 to 30'', nose radius: 0.2 rtm or more. This article focuses on cutting tools for aluminum alloys.

If the rake angle is less than 5'', the flank wear of the tool will increase, which is undesirable in terms of service life.At the same time,
In relation to tool wear, the cutting resistance increases as the wear progresses, and the surface roughness of the cut surface also increases. On the other hand, if the rake angle is too large, exceeding 30°, chipping tends to occur more easily.

The most suitable rake angle range is approximately 10 to 20 degrees.

On the other hand, the rounded nose helps prevent chipping. However, the nose radius is 0. 2
If it is less than rm, it is almost the same as when no roundness is imparted, and no improvement effect can be obtained. On the other hand, set the nose radius to 1. If you set it to one with a large curvature exceeding Om,
This is not preferable because cutting resistance increases. A suitable setting range for the nose radius is approximately 0.2 to 1.0.

By rounding the nose of the working diamond cutting tool, it is possible to reduce the concentration of stress on the edges of the cutting edge during cutting, thereby preventing the occurrence of chipping. Combined with this, it is possible to set a large rake angle, and by setting the rake angle between 5 and 30'', flank wear is reduced, and tool life is increased.
It also improves the smoothness of the finished surface.

Example Using diamond particles with an average particle size of 0.3 μm, the following A
Diamond cutting tools with various cutting edge shape specifications of , B, and C were manufactured.

A...Front rake angle 0'' - Side rake angle θ - Front relief angle 7'' (7π/180) - Side relief angle 7'' (7π/1
80) - Front cutting edge angle 8" (2π/45) - Side cutting edge angle 0
° - Nose radius OIM.

A--5... Lateral rake angle θ--5' (-π/3A
-5・・・・・・ /l θ-5″(π/36)A
-20... 〃 θ-20° (π/9)A-3
0... /l θ-30' (π/6)B...
...Front rake angle - 5 @ (-π/36) - Side rake angle θ - Front relief angle 5° (π/36) - Side clearance angle 5° (
π/36) - Front cutting edge angle 30° (π/6)t52 Cutting edge angle 0' -/-Z radius 0.4III11°B--5・
・・Side rake angle θ−−5” (−π/3B−−10・
... Side rake angle θ - -10" (-π/18) C... Front rake angle O" - Side rake angle θ - Front relief angle 5° (π/36) - Side clearance angle 5° (π/36)−
Front cutting edge angle 30e (π/6) - Side cutting edge angle Oe - Nose radius 0.41rJM.

C-5... Lateral/rake angle θ-5° (π/36
) C-15... 〃 θ-15' (π/12) By using the various cutting tools mentioned above, Aρ-17 shown in Table 1 below
%Si alloy (A-quality Te) was used as a work material and cutting was performed.

[Margin below]

Table 1 (Work material) Cutting conditions are cutting speed V-5TrL/S, feed f-〇,
1 mttr/rev, cutting depth t=1.0 m.

This was done as dry cutting without lubrication.

The results of the above cutting test will be explained below according to each evaluation item.

[Chipping]

Each cutting tool A (A--5, A-10, A-20, A-
30), B (B--5, B-10), C (C-5,
C-15), cutting was performed for 1700 sec in each case, and after the cutting was completed, the presence or absence of chipping on the cutting edge, that is, chipping, was examined.

As a result, the occurrence of chipping during cutting was determined by the following
It was as shown in the table.

As shown in the upper table of Table 2, for the test specimens of Group A without any roundness (hereinafter referred to as "nose R") on the nose, the rake angle was set to be negative (A--5). Although no chipping occurred, it was found that if the rake angle was set larger than 5° (π/36), chipping occurred and the product could not be used.

On the other hand, in the Bm and 0 group test specimens having a nose radius, no chipping occurred regardless of the rake angle. Therefore, it was found that adding a nose radius is effective in preventing chipping.

[Tool wear]

For the test specimens of group A, we selected the test specimen of A--5 (-π/36) that did not cause chipping as described above, and compared the wear width of the flank with the test specimens of group B and group 0. We investigated changes over time.

The results are shown in FIG. As shown in the same figure, it can be seen that the test specimen A--5, which does not have a nose R, has relatively large tool wear and a large tendency for the amount of wear to increase over time. On the other hand, the test specimens of group B and group 0 with nose R had relatively little tool wear, and moreover, the amount of wear tended to decrease as the rake angle increased. This is thought to be due to the fact that the nose is radiused, which reduces stress concentration on the edges of the cutting edge, resulting in less tool wear.

[Cutting resistance]

As a result of the above, test specimens in group A were excluded due to occurrence of chipping or large tool wear, and
The specimens of Group 0 and Group 0 were further examined for changes in cutting resistance over time.

The results are shown in FIG. According to the same figure, compared to the B group test specimens (B--5, B--10) where the rake angle was set to negative, the 0 group test specimens (C-5, C-15) have a larger rake angle.
, the principal component force (Transiential f
force) and the feed force (Traverslng f
'orce) are both small, indicating that the increase in cutting resistance during cutting is small. This relationship agrees with the above result that the larger the rake angle, the less tool wear.

[Finished surface roughness]

For each specimen of group B and group 0, after 5 seconds of cutting time and 1
The surface roughness of the finished surface of the workpiece after 500 seconds was examined.

The results are shown in Figure 3. From the figure, it was found that there was no clear characteristic difference in the relationship between rake angle and surface roughness.

Based on the above test results, the nose radius has been improved to avoid chipping and reduce tool wear.
It is preferable to give
It was confirmed that it is preferable to set the rake angle larger than 51 for the purpose of reducing the cutting resistance and obtaining a good finished surface. Note that the nose R has a radius of 0,
It is assumed that the effect cannot be fully achieved if it is less than 2 am n1
Therefore, it was predicted that when the rake angle is set to a large angle exceeding 30°, the effect of providing the nose radius will be lost and the occurrence of chipping will not be avoided.

Effects of the Invention According to the cutting tool having the cutting edge specifications according to the present invention, as described above, compared to the conventionally known and widely used diamond cutting tool suitable for cutting Ω-3l alloys, , is used to cut the same workpiece to avoid chipping while reducing tool wear, increasing its service life, and reducing cutting resistance to obtain a cut surface with even better smoothness. It has the effect of making it possible.

[Brief explanation of the drawing]

Figure 1 is a graph showing how the wear width of the flank face of the cutting tool under test changes over time, Figure 2 is a graph showing how the cutting resistance of the cutting tool under test changes over time, and Figure 3 shows the change over time in the wear width of the flank of the cutting tool under test. It is a graph showing a change in surface roughness of a finished surface cut by a tool. Patent applicant: Showa Aluminum Co., Ltd. 111.1
1-′,. Agent: Patent Attorney Daigi Shimizu: 4. ．．゛：、j、＞、
ゝ゛Pa1- J Nil Cutting (A) Fig. 3;) tn cutting direction (tc/s) Fig. 1 Fig. 2

Claims (1)

[Claims] A diamond cutting tool made of diamond or a sintered body thereof, in which the rake angle is 5 to 5 among the specifications of the cutting edge shape.
A cutting tool for aluminum alloy, characterized by having a nose radius of 30°: 0.2 mm or more.