JPS60118672A - Ceramic sintering body composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ceramic sintered body used in various articles requiring high hardness and wear resistance, such as cutting tool tips and bearings.

Recently, with the improvement of machine performance, each part has high strength and
Although high-hardness materials are being used, these parts are often made of materials that are difficult to machine.

This results in a decrease in machining efficiency.

Ceramic tools are generally said to be superior in cutting such difficult-to-cut materials, and currently there are two types of ceramic tools: simple types and AI! 20. -Tie type two systems are the mainstream. Especially the latter AI! , Q,
-Tie type products are said to be most suitable for this type of cutting, but none have yet appeared that fully satisfy the high efficiency machining required by the market.

That is, A/203 or MgQ, which has been commonly used
Aj'ff1O, sintered bodies containing trace amounts of grain growth inhibitors, such as Aj'ff1O, have high hardness and excellent wear resistance, and are widely used for high-speed cutting and precision finishing as bit tips for medium cutting in various wear-resistant porcelains. However, due to its poor toughness, its use was limited to light cutting only. To compensate for this drawback, high-toughness ceramics with added ties were developed, expanding the cutting range of ceramic tools, but the mechanical It is only used in a limited area for heavy cutting that involves vibrations and shocks, and is not yet widely used.

The present inventors previously aimed at strengthening T10 in an AJ, O, -Tie-based ceramic sintered body, and used Mu/, 0. −
A metal or an oxide thereof consisting of one or more of lJb, V, Ta, Zr or Hf in the Tie, and CIILOlMgO
, YzO@, 810g.

Developed a ceramic sintered body made by adding one or more of NiQ, D72 as, or an oxide of a rare earth element,
This makes it possible to manufacture tools that can be used for heavy cutting as described above.

As a result of further study on the above composition, the present inventors replaced a portion of TiC with MQB, MO□B8, and WB.

By replacing it with W2B or TaB, a ceramic sintered body composition with good sinterability and usable in a wider range of areas has been created.

That is, the present invention provides Tie and MoB, Mo, B, , WB, W, B, or T of 5 to 50 weights for Tie.
aB and one or more types of Nb in a total amount of 15 to 405 to 40% by weight.

1 to 10% by weight of one or more of V, Ta, Zr, or Hf metals or their oxides, ca□, MgO, NiO.

5102 s zro2 s D7101 s Y*O
a or one or more oxides of rare earth elements at 0.05
~3.0% by weight, balance A60. The present invention provides a ceramic sintered body composition comprising:

The basic composition of the present invention is Alzos and Tie, but M
oB.

Mo, B, , VB, W, B, or TaB,
It has been found that when a part of T10, that is, 5 to 50 folds of B1, is replaced with Ilp] compound shown in the formula, the sinterability of the composition is good, and in particular, a marked improvement in wear resistance is observed. Ta. The borides in the periodic table ■, ■, ■, and vI are generally similar to metals, but among them, MOB, M
O□B WB , W, B, , TaB, is A40. -T
It has been found that it is suitable for the iC system.

The present invention will be described in detail below. In the present invention, Ti
e improves the hardness and toughness of the sintered body, but the total amount, including that partially replaced with the aforementioned boride, is 15% by weight.
If it is less than 40% by weight, the effect will be too weak, and if it exceeds 40% by weight, the sinterability will decrease and wear resistance will be adversely affected.In the present invention, a part of this Tie, that is, 5 to 5010% M
2B, , WB %W, B.

Or, it is replaced with a boride called TaB2.

These borides have properties similar to metals and are the basic structure of the present invention. , 0. In the composite ceramic containing +TiC and other additives, it is believed that the bond between each component is strengthened. If the boride content is less than 5% by weight of the Tie, the effect is too low;
It is recognized that when it exceeds f%, the sinterability of the composition decreases, and the toughness and wear resistance are also inferior.

Next, Ti, llb, V, Ta, Zr or Hf (group ⅠA).

The reason for adding Group V A) metals or their oxides (hereinafter referred to as the first additive) is that the Tie can obtain a fine and uniformly dispersed structure, resulting in increased hardness and wear resistance. This is to improve the performance of the tool. In this case, the first additive is not limited to those added in the form of metals or metal oxides; for example, even if it is added in the form of an organic compound, the first additive may be the above-mentioned additive that changes into a metal or oxide during sintering. A similar effect can be obtained with substances. This effect is preferably from 1 to 10% by weight; if it is less than 1% by weight, the effect is insufficient, and if it exceeds 10% by weight, the toughness will be rather poor.

Next (2 CaQ, MgO, Ni0, +310.,
zro,,D7203°T20. Alternatively, the reason why one or more types of rare earth element oxides (hereinafter referred to as second additives) is added is to suppress the growth of these alumina crystal particles and promote sintering at the same time. The effect is 0.
If it is less than 0.05 weight, the effect is insufficient, and 3.0 weight'f
If it exceeds t, the wear resistance and toughness at high temperature or room temperature will decrease.

Next (2) Regarding the method for manufacturing a tool having a composition based on the present invention, 1. A well-known method for manufacturing a ceramic composition can be used, but the firing atmosphere must be a non-oxidizing atmosphere such as nitrogen gas or argon gas. In an atmosphere containing a large amount of oxygen, the Tie is oxidized and does not exhibit its original characteristics.

The present invention will be explained in more detail below using sample examples, but the present invention is not limited to the scope of these examples.

Sample preparation example 1 Cl-A120a with 70% particle size of 1/j'772 or less
TiO with an average particle size of 1.2 μm and a total carbon content of 19.4% and boride with a particle size of 2 to 10 μm (F, S, 8.8) (However, MoB, MoB, WB, W, B, or TaB
) and the first additive and second additive that have passed through 325 mesh are blended in the proportions shown in the table below,
After wet grinding with acetone in a stainless steel ball mill for about 30 hours, the acetone was volatilized in a dryer, and then crushed in a mortar for 6 hours.
Finely grind the base powder until it passes through a 0-mesh sieve (
A) (hereinafter abbreviated as gradation) is prepared. (After adding 5 g of paraffin to gradation and passing the entire amount through a 60 mesh sieve, the pressure I Vcm" cD positive pressure 16 x 16 x 7,51
1! Pressure mold into M rectangular parallelepiped. Obtained molded body (B)
(hereinafter abbreviated as CB+) is sintered (hereinafter referred to as "normal sintering J") for 1 hour at the sintering temperature shown in the table under a reduced pressure argon atmosphere.

The obtained sintered body was polished to a size of 5NG using a diamond grindstone.
N432 TN, the surface was polished to 3S or less, and its properties were measured, and the results are shown in the table.

Sample Preparation Example 2 Prepared in the same manner as in Example 1 (pressure sintering method at the sintering temperature shown in the table, pressure 200 to 9/cM2, pressure firing time 15 minutes) 13X13 in Yoshi graphite mold
A square plate of x6** was sintered, and the polishing properties were measured in the same manner as in Example 1, and the results are shown in the table.

Sample Preparation Example 3 A primary sintered body was prepared from TB molded in the same manner as in Example 1 under reduced pressure argon atmosphere at the sintering temperature shown in the table for 1 hour, and this was further sintered at the sintering temperature shown in the table. pressure 15001g/1
No. 112 was sintered by isostatic pressure sintering under conditions of a holding time of 1 hour, polished in the same manner as in Example 1, and its properties were measured. The results are shown in the table.

However, the conditions for the cutting test are as follows.

Work material: Fe12 (HB200-240) Cutting speed (V
l = 800 m/min depth of cut (t) = 0.5 m feed rate (f) = = 0.2 wM/rev life judgment: 120φx15tyl! cy) As can be seen from the measurement table of the wear width VE (m) after cutting the outer periphery 150 times, the Cefmic sintered body of the present invention has AI! 2o, of course alone,
Compared to A/, O, -TiO type ceramic sintered bodies or ceramic sintered bodies that do not meet the blending amounts of each composition specified in the present invention, the hardness and cutting performance are significantly improved, and the material is free from mechanical vibration and impact. This makes heavy cutting possible.

The ceramic sintered body obtained according to the present invention can be used as a cutting tool for castings, metals other than high hardness materials and high nickel alloys, such as aluminum, steel, etc., and non-metallic materials, and can also be used as cutting tools for cutting tools that are subjected to severe vibrations. It can also be used in mechanical parts that are used at high temperatures.

Agent: Patent Attorney Mamoru Takeuchi

Claims (1)

[Claims] A Tie and 5 to 50% by weight of MoB based on the Tie. MO, B, WB, W, B, or TaBt, totaling 15 to 40% by weight, Ti% Mb, V, Ta. 1 to 1 of Zr or Hf metals or one or more of their oxides
0 weight*, aaQ, MgO, Ni01EliO,,
ZrQ, , D3'20m, Y, 03 or one or more oxides of rare earth elements in an amount of 0.05 to 5.0% by weight, the remainder A7. A ceramic sintered body composition characterized by comprising O.