JPS60127905A - High touchness ceramic tool - Google Patents

Abstract

PURPOSE:To obtain high toughness and hard ceramic tool by providing a very hard coating layer of such as TiC, TiN on the surface of a base material made of a predetermined ceramic sintered body having sufficient strength and toughness. CONSTITUTION:This ceramic tool is made by forming a coating layer of TiC, TiN, TiCN, Al2O3 or AlON, or combination of them on the surface of a base material made of Al2O3-ZrO2 group ceramic sintered body. The ceramic sintered body should be composed of ZrO2 of 0.1-99.9wt% and Al2O3 for the rest, desirably composed of ZrO2 of 1-30wt% and Al2O3 for the rest, and ZrO2 should be partially stabilized by adding CaO, MgO, Y2O3 or rare earth oxide or combination of them.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high toughness ceramic based on an Al2O3Z r 02 -based ceramic sintered body.

Conventional A, O3 threads and Al2O3-TjC ceramic ceramic undercoats have the advantage of being highly hard at high temperatures, but on the other hand, they do not necessarily have good strength or toughness, so they cannot be passed through during rough processing, and In the recent situation where the use of NC in machine tools is progressing, there is a drawback that reliability as a tool is poor.

On the other hand, as disclosed in JP-A-55-140762, Z r 02 ceramic ceramic tools have a transverse rupture strength of 10
It has excellent properties such as 0kg/mrn' or higher and toughness (Kic) of 30.
O2-based Ceramink contains ZrO2 as the main component and Cao
, Mg0. It is obtained by adding oxides such as y2o3 to partially stabilize high-temperature stable phases such as tetragonal and cubic crystals even at room temperature.

In addition, Japanese Patent Application Laid-open No. 52-86413 and Japanese Patent Application Laid-Open No. 54-60 disclose A-pattern λ03-Z r 02 ceramics.
According to No. 308 and Japanese Unexamined Patent Publication No. 54-61215, ZrO! It is known that considerably high toughness can be achieved by dispersing .

However, when such conventional ZrO2-based ceramics and Al2O3ZrOz-based ceramics are used as cutting tool materials, they are superior in strength and toughness compared to Au203-based ceramics, AM, and 03-Tic-based ceramics. Therefore, it is suitable for rough machining, but on the other hand, when cutting tile cast iron or steel, for example, both flank wear and crater wear become W4. For this reason, conventional tools made of Z r 02 series ceramics or Al2O3"-Z r 02 series ceramics have poor wear resistance and cannot exhibit superior functions as cutting tools.

The present invention has been made by paying attention to these points.
The object of the present invention is to provide a ceramic tool having particularly high hardness as well as strength and toughness as high as 1-minute.

To this end, the ceramic upper of the present invention is provided with a coating layer having high hardness on a base material having superior strength and toughness.

That is, the present invention uses A Q203 Z r as a base material.
02 series ceramic and -TjC, TiN, T1CN, Al as a seedling layer formed on its surface;, 03
, by constituting at least one species of ceramic.

We provide tools made of "ceramink with high toughness and high hardness." The base material is Z r 02 type or A n,,C)3 Z r 0
It consists of a 2-series ceramic sintered body.

No. 1 (The composition of the A i, o3 Z r 02 ceramic sintered body as a material is ZrO'2 0, 1 to 99
, 9wt%, balance A1203, preferably Z
ro21-30 wt%, balance A, Q203 is good.

The reason why Z r 02 was made more than O.1wt% was because Z r 02
02100wt% has sufficient strength and toughness, and Al2
When ZrO2 is added to O3, the strength of AsL2o3,
This is particularly because toughness is improved. In addition, ZrO2 was added to 3
When the content is 0 wt% or less, favorable properties can be obtained in terms of hardness of the base material. That is, while the micro Vickers hardness of ZrO2 is about 1100 kg, 'rnm', A
Sentence>03(7) Sore indicates 2000kg/mm7 or more. If the Zr content is 21 wt% or more, the strength and toughness are further improved, which is preferable.

Among these, ZrO2 is preferably CaOlMgO, Y
, +03, etc., but need not necessarily be included. When using the stabilizer, Ca
0 or M g O in total is 15 wt% or less with respect to Z r 02 , and Y2O3 is also Z r 02
It is preferably 9 wt% or less.

In this case, the additive ZrO2 is 7 to 1 for the total amount of 2.
[It is preferable to have a partially stabilized structure containing 5 wt % or more of square ZrO2. In addition, ZrO2 is added to AQ and 2O3.
When adding Z r 02 that has been partially stabilized in advance
may be added to A fL203 , or monoclinic Z
rOλ and a stabilizer may be added to A sentence and O3 individually.

・If no stabilizer is included, the average particle size is 0.3 μm.
Preferably, the following Z r 02 is used. ZrO
When fine particles of ZrOλ are dispersed in No. A O3 when adding No. 2 to A 1203, ZrO2 (positive) remains as a single product, which results in A 1203 Z with good toughness.
This is because r02-based ceramics can be obtained.

In addition, when using a ZrO2-based ceramic sintered body as a base material, it is desirable to include a stabilizer, and A 1z03
The same is true when there is not a small amount.

The firing conditions for the Z r 02 series or A pattern, 03 2 r 02 series serayusoku base material are: temperature 13 in an oxidizing atmosphere.
50 to 1650'c and a processing time of several minutes to several hours. If the temperature is lower than 1350°C, sintering will not be sufficient, and 1
If the temperature exceeds 650°C, the growth of crystal grains will become significant and both the strength and toughness of the base material will deteriorate.
Above, fracture toughness plKic 10kg/m or above), 0bc
Z&, hope.

stomach.

Next, the ceramics used as coating materials are TiC1TiN, T
It is made of 1CN, AfLON, AfLON, or a combination of these components, and may be coated in a single layer or in multiple layers on the surface of the base material. When the above components are combined to form a multilayer coating, the covered layer should be two or more layers, for example, an inner layer, an intermediate layer, and an outer layer as shown in Table 1 (Al0N is preferable as the intermediate layer). )
.

The coating method in this case is the PVD method (Physical V
apor deposition) and CVD method (Che
Mical Vapor.

Although other physical or chemical deposition film formation methods may be used, from the viewpoint of uniformity of adhesion of the coating material and coating speed, it is preferable to use the CVD method using the reaction shown below. .

T + CI++ CH Beef TiC+4HC12Tl
CI4+Nyu+4H□-→2TiN+8HC:
12TiCI++ 2GH++N, -→2TiGN +
8HG12A1 (:13 + 3G0U+3H2-→A
1yo03 + 3C0+ 8) 1C; 12AICI +
2C0□1N2+3)+2-→2AlON+ 2C0
+ 6HCITiC, TiN, T1CN, A-view, O3,
The shoulder side of the A-mon ON coating method is known per se, and will not be described here.

There are many methods for applying various coating layers to cemented carbide by the CVD method, including Japanese Patent Publication No. 42013 (TiC), and Japanese Patent Publication No. 51-24982 for TiN and T1CN.
Achi O3 is published in Japanese Patent Publication No. 48-217, TiC, TiN/A Island 03 and A Bun ON/A Bun Yu O3 are covered in Japanese Patent Publications No. 52-13201 and Patent Publication No. 54-29185, respectively.
Similar coating methods can be used. However, these are
However, since both of them are made of cemented carbide as an IfI material, they are not suitable for high-speed cutting.

The thickness of the coating layer is preferably 0.3 to 15 pm.

This is because if it is less than 0.3 gm, its function as a coating material will be weakened, and if it exceeds 15 gm, grain growth will be significant and it will be easy to peel off during coating. A 1,03
The thickness of the A 1x03 layer in the case of coating is preferably about 0.3 to 5 m.

Ceramic tools constructed in this way have high strength,
In addition to having high toughness, it also exhibits excellent properties in terms of wear resistance. This will be explained based on the following experimental example.

The raw materials used for the base material have purity (w) for A203.
t%) 99.9%, average particle size 0.6 gm, monoclinic ZrO
For λ, purity is 99% or more, average particle size is 0.2 gm
, for CacO3, raw material Ca0 purity is 98%, MgO
The purity was 97% or higher for Y and L03, and the purity was 99.9% or higher for Y and L03.

Each sample of the base material had a composition as shown in Table 2, and after wet-mixing predetermined raw materials, drying, adding a binder, granulating, and press-molding at a pressure of 1.5 kg/crt+'. After removing the binder from this compact by calcination,
1a1 was fired at 1400 to 1650°C in an electric furnace. This sintered body was polished to a size of 4 x 8 x 25 mm.

The characteristics of each sample thus prepared are shown in Table 2. As is clear from Table 2, each trial $′l is
Tsurutsune's A text, L03 transverse rupture strength 50 kg/...Hereinafter, toughness (K...)lokg/...- also shows considerably high transverse rupture strength and toughness compared to U) Ru.

The method for measuring each characteristic of the sample is as follows. C1)
Bending strength is measured according to JIS B12O3, 5 wood] (
Indicates the l average value. (2) Fracture toughness is determined according to ASTM Special Technical No. 410.
A notch with a depth of 0.5'mm and 11]0.15+rzn was made in a specimen measuring 4 mm in width, 5 mm in thickness, and 25 mm in length, and a "-τ point bending cut of 20 mm in diameter was made. It was measured by the chipping method. The constant value is the average value of 1 for each of the 5 ends. (3) The crystal system was determined by X-ray diffraction using a Geyker Flex RAD-γA manufactured by Rigaku Denkai Co., Ltd.

First, X-ray diffraction was performed on a specimen mirror-polished with 15 gm diamond paste, and the (111) plane and (1
11) Integrated intensity In of the surface and (111
) plane and the (111) plane of cubic ZrO3 -
The amount of monoclinic ZrOλ was determined from the ratio of It+Ie.

The sintered body was then crushed to a 325-mesh size, subjected to X-ray diffraction under the same conditions, and the integrated intensities I'm and Ie of monoclinic ZrOλ and cubic ZrO3 were determined again. At this time, the residual tetragonal ZrO2 in the sintered body is subjected to mechanical stress due to crushing,
All from the monoclinic crystal (I'm + I'e))' heptagonal Zr03-9 was determined, and then the jFgonal crystal ZrOλ was also determined I7.

Next, each of these samples was 5NGN4'32TN (JIS
A predetermined coating layer was formed on the surface of this molded body (base material) by CVD method. Specifically, H2 scum was poured into the container as a carrier sludge into the container with the base material set, and 41 predetermined coating materials were deposited on the surface of the base material through the aforementioned chemical reaction (see Table 3). reference). The internal pressure of the reaction vessel is T
100mb when covering iC, AΩyu O3, AMON
, the same (300 mb for T i CN, 500 mb for TiN+, and the temperature in the reaction vessel was set at 1050'c. The coating rate was lpm/hr for TiC, TiN, and T1CN, A, O,... For AlON, it was set at 0 and 5 gm/hr.

Using the ceramic tool (sample) obtained in this way, price cutting of ductile cast iron (FCD55) (
Test 1) and chromium molybde 7 alloy mesh (30M44C
) turning (Test 2) was performed. The cutting conditions are shown in Table 4.

The results of this cutting test are shown in Table 3, and as can be seen from this table, after 11 tests, Samples Nos. 3 to 8 were able to withstand approximately 5000 impacts. In contrast, sample No. 1.2 and 91±2000-300
It will break after 0 impacts (l/). However, these No.
Both groups 3 to 8 and No. 1.2.9 are Comparative Example 1
- A is suitable as a coating layer because it has a considerably longer lifespan than 4.
It can be seen that the lz03-ZrOλ ceramic is particularly effective for milling ductile cast iron at a given film thickness. Also, from Test 2, A as a coating layer was similarly found.
It can be seen that u, o3 Z r 02 -based ceramics have excellent flank wear resistance in turning steel.

As explained above, according to the present invention, A
12o3-Z r Oλ ceramic is used, and TiC, T as a predetermined thin film is coated on the surface of the base material.
Since a coating layer made of at least one type of ceramic of iN, T1CN, A-bun Yu03, and A-bun ON was formed,
It not only exhibits high strength and toughness, but also has the effect of exhibiting excellent wear resistance that was not available with conventional ceramic tools.

The ceramic tool of the present invention can be used not only as a cutting and turning tool, but also as a wire drawing die and other metal processing tools that are required to have wear resistance, toughness, and hardness.

Claims (1)

[Claims] (1) TiC, TiN, TiCNA on the surface of a base material made of A 1zoa Z r 0λ ceramic sintered body.
A high-toughness ceramic tool characterized by forming a coating layer made of AJION, AJION, or a combination thereof. A tool according to claim 1 consisting of. (3) A %03-Zr02 ceramic sintered body contains ZrO2l ~ 30wt%, balance An, 03(
1) The tool according to claim 2, consisting of a composition. (4) The device according to claims 1 to 3, wherein Z r and Oλ do not contain a stabilizer. (5) Zr0λ is a claim f containing a stabilizer.
f11--The tool according to item 3. (8) Z r 02 is Ca0. MgO1Y203
The tool according to claim 5, which is partially stabilized by the addition of a rare earth oxide or a combination thereof. (7) The coating layer is composed of at least two layers, an inner layer and an outer layer, the inner layer is made of TiC, TiN or T1CN or a combination thereof, and the outer layer is made of Al, 03. Tools listed in. (8) Al0N in the intermediate layer between the inner layer and outer layer in the coating layer.
The tool according to claim 7, comprising: (8) The tool according to claims 1 to 3, wherein the coating layer comprises an inner layer Al0N and an outer layer AlλO3. (10) The tool according to any one of claims 1 to 9, wherein the coating layer has a thickness of 0.3 to 15 #Lm. (11) T i C, T, i N, Ti CN, Al,
A high-toughness ceramic tool having a coating layer formed of a coating material made of 03, Al0N, or a combination thereof. (12) The tool according to claim 11, wherein the two-piece O2-based ceramic sintered body is partially stabilized ZrO2. (13) The tool according to claim 11 or 12, wherein the coating layer has a thickness of 0.3 to 15 #Lm.