JP2895163B2 - Cutting tools - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cutting tool, and more particularly to a cutting tool having a throw-away tip made of Al ₂ O ₃ -based ceramics, particularly a high-manganese cast steel or the like. The present invention relates to a cutting tool used for cutting hard-to-cut materials such as hard-to-cut cast iron.

(Prior art) High manganese cast steel has high strength and hardens during machining, so it is a difficult-to-cut material that is extremely difficult to machine. Spheroidal graphite cast iron (FCD) has high strength and high toughness and is difficult to cut, and austempered ductile cast iron (ADI) is extremely difficult to cut because work hardening occurs further. Also, since 27% Cr cast iron has extremely high hardness, cutting is difficult.

As cutting tools for cutting difficult-to-cut materials as described above,
It is required to have high hardness and high strength at high temperature. Conventional cutting tools cannot satisfy the demand, but among them, carbide tools have relatively high hardness and strength at relatively high temperatures,
It is used for cutting difficult-to-cut materials such as high-manganese cast steel.

However, when cutting hard-to-cut materials using a cemented carbide tool, cutting cannot be performed unless the cutting speed is extremely low. Therefore, there is a problem that the cutting efficiency is extremely low and the cutting process requires a long time.

Therefore, in order to solve such a problem, various studies have been conducted focusing on ceramics having high hardness and high strength at high temperatures, and recently, cutting of Al ₂ O ₃ -TiC-based ceramics or Si ₃ N ₄ -based ceramics has been performed. Tools are being developed.

(Problems to be Solved by the Invention) However, when the above-mentioned cutting tool made of Al ₂ O ₃ —TiC ceramics is used for cutting hard-to-cut materials such as high-manganese cast steel, it lacks toughness and has poor fracture resistance. There is a disadvantage that
For this reason, there is a problem that cutting with an extremely small cutting depth is inevitable, cutting efficiency is extremely low, and cutting requires a long time.

When a cutting tool made of Si ₃ N ₄ ceramics is used for cutting difficult-to-cut materials such as spheroidal graphite cast iron, there is a problem that abrasion due to the reaction with cutting chips is apt to occur, and therefore the life of the cutting tool is short.

As described above, the conventional cutting tool has a problem in that sufficient cutting performance cannot be obtained when used for cutting difficult-to-cut materials.

The present invention has been made in view of such circumstances, and has as its object to solve the above-mentioned problems of conventional products, to have high hardness and strength at high temperatures, and to use conventional ceramics. An object of the present invention is to provide a cutting tool having excellent toughness, excellent fracture resistance and wear resistance as compared with a cutting tool, and suitable for cutting difficult-to-cut materials.

(Means for Solving the Problems) In order to achieve the above object, a cutting tool according to the present invention has the following configuration.

That is, the cutting tool according to claim 1 contains 3 to 40% by weight of SiC whiskers and one of carbides, nitrides, and carbonitrides of Si, V, Cr, Zr, Nb, Mo, Hf, Ta, and W. 0.5 to 40 wt. Of seed or 2 kinds
A cutting tool having a throw-away tip made of an α-type Al ₂ O ₃ -based ceramic containing at least 30% by weight, wherein the SiC whisker is oriented parallel to a rake face of the throw-away tip.

The cutting tool according to claim 2, wherein the SiC whisker is O
The cutting tool according to claim 1, wherein the amount is 0.3 to 1.5 wt%.

The cutting tool according to claim 3, wherein the carbide, the nitride,
The cutting tool according to claim 1, wherein one or two or more of carbonitrides are dispersed in Al ₂ O ₃ crystal grains in a nano-order to exhibit a nanocomposite structure.

Cutting tool according to claim 4, wherein the Al ₂ O ₃ based ceramic material is, Y ₂ O ₃ as a sintering aid, MgO, ZrO _2, titanium oxide, chromium oxide, nickel oxide, one chromium carbide or Claim 1, wherein two or more kinds are contained in an amount of 0.5 to 10.0 wt%.
A cutting tool according to claim 2 or 3.

(Action) As described above, the cutting tool according to the present invention contains SiC whiskers in an amount of 3 to 40% by weight and Si, V, Cr, Zr, Nb, Mo, Hf,
Ta, carbides of W, a nitride, one or two (hereinafter, referred to as carbides) of carbonitride throw-away tip (hereinafter, referred to as chips) made from Al ₂ O ₃ based ceramic material containing 0.5 to 40% with a Like that.

When SiC whiskers are contained in Al ₂ O ₃ -based ceramics in this way, the ceramic matrix is strengthened and toughened without lowering the properties inherent in Al ₂ O ₃ -based ceramics, and as a result, fracture resistance The performance is improved. In addition, when carbides and the like are included, the structure of the ceramics becomes finer and abnormal crystal grain growth is suppressed,
As a result, the strength can be further improved. Therefore, the tip can have high hardness and high strength, excellent wear resistance and chipping resistance.

Here, the reason why the content of SiC whiskers is set to 3 to 40 wt% is that if the content is less than 3 wt%, the effect of increasing the toughness is small.
If it exceeds 0 wt%, SiC, which has reactivity with iron, relatively increases, thereby deteriorating abrasion resistance, and a sufficient uniform dispersion state of SiC whiskers cannot be obtained, resulting in a decrease in strength. . The SiC whiskers have a needle-like shape.

The reason why the amount of carbides and the like is 0.5 to 40% by weight is that if the content is less than 0.5% by weight, the effect of improving the strength is reduced, and if it exceeds 40% by weight, a dense sintered body cannot be obtained due to a decrease in sinterability.

In the cutting tool according to the present invention, the SiC whiskers are further oriented parallel to the rake face of the throw-away insert. That is, the SiC whiskers are two-dimensionally oriented in the rake plane such that the axial direction of the needle-like SiC whiskers is parallel to the rake plane. When the SiC whiskers are oriented in this manner, the SiC whiskers have an extremely strong resistance to the main component force during cutting. Therefore, the fracture resistance is further improved. In addition, 2 of whisker as mentioned above
The dimensional orientation does not need to be formed in the entire chip, but may be formed at least in the rake plane that directly affects cutting performance such as chipping resistance, that is, in the vicinity of the rake plane. Regarding the arrangement relationship between the two-dimensionally oriented whiskers, the whiskers may be parallel, orthogonal, radial, or at random.

When the O content of the SiC whisker is set to 0.3 to 1.5 wt%,
This is because a sufficiently uniform dispersion state of the whiskers can be easily obtained, and high strength can be easily ensured. That is, the Al ₂ O ₃ -based ceramics are usually manufactured by dispersing SiC whiskers in a solvent to form a slurry, mixing the slurry with Al ₂ O ₃ powder, carbide and the like, and sintering. When such SiC whiskers are dispersed in a solvent,
When the O content in the whiskers is 0.3 to 1.5 wt%, the whiskers are dispersed very uniformly, and as a result, a sintered body in which the SiC whiskers are uniformly dispersed is easily obtained. When the O content is less than 0.3 wt%, the above-mentioned uniform dispersion effect is reduced.
The reaction between iO ₂ and Al ₂ O ₃ occurs, causing a reduction in strength.

When a part of the carbide or the like is dispersed in Al ₂ O ₃ crystal grains in a nano order to exhibit a nanocomposite structure,
Further strength is improved. This is the effect of the combination of nanocomposite reinforcement with carbides and the like and fiber reinforcement with SiC whiskers.

The Al ₂ to O ₃ based ceramic material, Y ₂ O ₃ as a sintering aid, Mg
When one or more of O, ZrO ₂ , titanium oxide, chromium oxide, nickel oxide, and chromium carbide are added in an amount of 0.5 to 10 wt%, sinterability is improved, and the sintered structure is refined and uniform. It is easy to secure high strength and high toughness. This effect is extremely small when the added amount is less than 0.5 wt%, and 10.0 wt%
If it is higher, the high-temperature strength will decrease.

(Example) Example 1 SiC whiskers in which the amount of O was adjusted to 0.6 wt% were added to a solvent, ultrasonic energy was applied for 30 minutes, and uniformly dispersed in the solvent to obtain a slurry. Al ₂ O ₃ powder and carbide, etc., or further a sintering aid are added to the slurry,
After stirring and mixing for hours, dry with a spray dryer.
Granulated. The obtained mixed powder is packed in a graphite mold,
Uniaxial pressure sintering was performed in an Ar gas stream at 1850 ° C. and 200 kg / cm ² by hot pressing for 30 minutes to obtain a sintered body (ie, Al ₂ O ₃
Base ceramics). By doing so, the whiskers in the sintered body can be oriented two-dimensionally in parallel with the hot press surface. The amounts of SiC whiskers and carbides, and the types and amounts of sintering aids were changed. The amount of these additives
It is shown in the table.

A 5.2 x 13.5 x 13.5 mm chip is cut out from the sintered body so that the hot-pressed surface and the rake face of the chip are parallel, and the chip is polished to a SNGN 434 T-4 shape (ISO standard). processed. The front view of this chip is
In the figure, a side view is shown second. In these figures,
(1) indicates a rake face, (2) indicates a round corner portion, (3) indicates a honing portion, and (4) indicates a honing width. The corner radius of the round corner portion (2) is 1.6 mm, and the honing width (4) is 0.2 mm.

Attach the above tip to a cutting tool and use it as a tool.
Cutting tests were performed using FC25, FCD45, ADI and 27% Cr cast iron as the work material under the cutting conditions shown in Table 2. Table 1 shows the test results. Note that, in this experimental example, all the tissues had a nanocomposite structure.

Example 2 A milling cutter (Φ200, Φ200,
A milling test was performed under the cutting conditions shown in Table 3. The test results
It is shown in the table.

Comparative Example 1 By the same method (operation, procedure, and conditions) as in Example 1,
A sintered body was obtained. Table 5 shows the addition amounts of the SiO whiskers, carbides, and the sintering aid at this time. Regarding the amount of O in the SiC whiskers, Experiment Nos. 5 and 6 were 0.1 and 2.0 wt%, and the others were 0.6 wt% as in Example 1.

Chips having the same dimensions were cut out from the sintered body by the same method as in Example 1. However, in the case of Experiment No. 7, unlike the case of Example 1, the hot press surface and the rake surface of the chip were orthogonal to each other. I cut it out.

The chip was mounted on a cutting tool, and the same cutting test as in Example 1 was performed. Table 5 shows the test results.

Comparative Example 2 A chip having the same shape as in Example 2 was cut out from the same sintered body as in Comparative Example 1, and the same milling test as in Example 2 was performed. Table 6 shows the test results.

Comparative Example 3 Carbide tip, Al ₂ O ₃ tip, Al ₂ O ₃ -TiC tip, S
The same milling test as in Example 2 was performed using an i ₃ N ₄ type chip. Carbide tips have large crater wear in tests Izure, except that becomes impossible cutting within 5 minutes, Al ₂ O ₃ system and Al ₂ O ₃ -TiC based chip test simultaneously with the start of defect, Si ₃ N
After showing that the ₄ series tip had a great corner wear,
The defect occurred within 3 minutes, and stable cutting was not possible.

(Effect of the Invention) The cutting tool according to the present invention has high hardness and strength at high temperature and has excellent toughness as compared with a conventional ceramic cutting tool, and thus has excellent fracture resistance and wear resistance. , A cutting tool suitable for cutting difficult-to-cut materials. Therefore, according to the cutting tool of the present invention, even in the case of cutting difficult-to-cut materials, it is possible to perform high-cut and high-speed cutting without causing chip loss or wear, and as a result, it is possible to improve cutting efficiency, In addition to shortening the processing time, the life of the cutter can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing the shape of the throw-away tip according to the first embodiment, and FIG. 2 is a side view showing the shape of the throw-away tip according to the first embodiment. (1) Rake surface (2) Round corner (3) Honing part (4) Honing width

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-89471 (JP, A) JP-A-1-215947 (JP, A) JP-A-61-124548 (JP, A) JP-A-61-124 110745 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B23B 27/14 C04B 35/10

Claims (4)

(57) [Claims] 1. A method for manufacturing a semiconductor device, comprising: 3 to 40% by weight of SiC whiskers;
Indexable inserts made of α-type Al ₂ O ₃ based ceramics containing 0.5 to 40 wt% of one or two of carbides, nitrides and carbonitrides of V, Cr, Zr, Nb, Mo, Hf, Ta, W A cutting tool having the SiC whiskers oriented parallel to the rake face of the indexable insert. 2. The cutting tool according to claim 1, wherein the SiC whisker has an O content of 0.3 to 1.5 wt%. 3. The method according to claim 1, wherein one or two or more of the carbides, nitrides, and carbonitrides are dispersed in Al ₂ O ₃ crystal grains in a nano-order to exhibit a nanocomposite structure. The described cutting tool. 4. The method according to claim 1, wherein the Al ₂ O ₃ -based ceramic comprises one or more of Y ₂ O ₃ , MgO, ZrO ₂ , titanium oxide, chromium oxide, nickel oxide, and chromium carbide as sintering aids. ~ 10.0w
Claim 1, Claim 2 or Claim 3 in which t% is contained.
The cutting tool according to 1.