JPH04304904A - Cutting tool made of titanium carbonitride group ceramics excellent in wear resistance - Google Patents

Abstract

PURPOSE:To improve the wear resistance of a cutting tool made of a TiCN group ceramics. CONSTITUTION:A cutting tool is composed of a sintered body in the compounding composition consisting of either or both of ZrO2 and stabilized ZrO2 5-30%, TiB 5-30%, TiCN the rest, in wt.%.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool made of titanium carbonitride (hereinafter referred to as TiCN)-based ceramic having high strength and hardness and exhibiting excellent wear resistance in practical use.

0002

[Prior Art] Conventionally, for example, Japanese Patent Application Laid-Open No. 62-148367
As described in the publication, zirconium oxide (hereinafter referred to as Z
rO2), and ZrO2 stabilized by solid solution of one or more of Y, Mg, Ca, and oxides of rare earth elements at a ratio of 0.1 to 3 mol%, Or TiCN, which is a sintered body with a compound composition (the above is weight %, the below % is weight %): both: 5 to 30%, and the rest: titanium carbonitride (hereinafter referred to as TiCN): the rest
It is well known that cutting tools made of base ceramics are used for cutting ductile cast iron, steel, and the like.

0003

[Problem to be solved by the invention] On the other hand, in recent years, the performance of cutting machines and the use of FA have been remarkable, and along with this,
There is a strong desire for the cutting tools used in these applications to have a much longer service life, but the conventional TiCN-based ceramic cutting tools mentioned above do not have sufficient wear resistance, so these demands cannot be met. The current situation is that it is not possible to respond satisfactorily.

0004

[Means for solving the problem] Therefore, the present inventors
From the above-mentioned viewpoint, we focused on the conventional TiCN-based ceramic cutting tool described above and conducted research to improve its wear resistance. When titanium boride (hereinafter referred to as TiB2) is added to
The TiB2 component contributes to improving the strength and hardness of the above-mentioned ceramics, and therefore, when used as a cutting tool, it exhibits excellent wear resistance, making it possible to further extend its service life. The research results showed that.

[0005] This invention was made based on the above research results, and it
Either or both of 2: 5-30%, Ti
The present invention is characterized by a TiCN-based ceramic cutting tool which is composed of a sintered body, preferably a hot-pressed sintered body, with a blending composition of B2: 5-30% and TiCN: the balance.

Next, the reason why the composition of the TiCN-based ceramics constituting the cutting tool of the present invention is limited as described above will be explained.

(a) ZrO2 and stabilized ZrO2
These components have the effect of improving toughness and thereby improving fracture resistance, but if the proportion is less than 5%, the desired effect of improving the above effect cannot be obtained;
%, the toughness not only tends to decrease, but also the hardness, so the ratio was set at 5 to 30%.

(b) TiB2 The TiB2 component has the effect of refining the structure and improving strength and hardness, but if its proportion is less than 5%, the desired effect cannot be obtained; The percentage is 30%
If it exceeds this, the toughness will decrease and the cutting edge will be more likely to be damaged, so the ratio was set at 5 to 30%.

[0009]

[Example] Next, the cutting tool of the present invention will be explained in detail with reference to an example.

[0010] As raw material powder, each has a diameter of 0.2 to 2 μm.
TiCN powder with an average particle size within the range of ZrO2
Using powder, stabilized ZrO2 powder containing the oxides shown in Tables 1 and 2 as a solid solution, and TiB2 powder, these raw powders were blended into the composition shown in Table 1, and the following were wet-processed under normal conditions. After mixing and drying, this was hot pressed at a predetermined temperature within the range of 1600 to 1900°C and a pressure of 300 kgf/cm2.
A sintered body with dimensions of diameter: 50 mm x thickness: 7 mm was measured for Rockwell hardness, 3-point bending strength, and fracture toughness, and further measured according to JIS/SNG.
The TiCN-based ceramic cutting tools of the present invention (hereinafter referred to as the cutting tools of the present invention) 1 to 10 and TiB2 are processed into cutting chips having the shape of N120408.
Conventional TiCN-based ceramic cutting tools 1 to 10 (hereinafter referred to as "conventional cutting tools") containing no TiCN-based ceramics were manufactured, respectively.

[0011]

[Table 1]

0012

[Table 2]

[0013] Next, regarding the various cutting tools obtained as a result, Work material: JIS/SCM440 round bar, Cutting speed: 30
0m/min, feed: 0.3mm/rev. A wet continuous cutting test was conducted on steel under the following conditions: depth of cut: 1 mm, cutting time: 10 minutes, and the flank wear width of the cutting edge was measured. These measurement results are shown in Tables 1 and 2, respectively.

[0014]

Effects of the Invention From the results shown in Tables 1 and 2, the cutting tools 1 to 10 of the present invention have a TiCN-based ceramic that constitutes the cutting tools 1 to 10. Because it has hardness and strength,
It is clear that during cutting, the wear resistance is significantly superior to that of conventional cutting tools 1 to 10.

As mentioned above, the TiCN-based ceramic cutting tool of the present invention has high hardness and high strength due to the TiCN-based ceramic that constitutes it, and therefore, when it is put into practical use, it will have even better durability. Since it exhibits abrasion resistance and can further extend its service life, it has industrially useful properties such as being able to fully respond to the high performance and factory automation of various cutting machines.

Claims (1)

[Claims] 1. Either or both of zirconium oxide and stabilized zirconium oxide, in weight percent:
A cutting tool made of titanium carbonitride-based ceramics with excellent wear resistance, characterized by being composed of a sintered body having a composition of 5 to 30% titanium boride, 5 to 30% titanium boride, and the remainder titanium carbonitride. .