JPS62288169A - Manufacture of titanium-containing composite carbonitride - 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] 3. Detailed Description of the Invention (Field of Industrial Application) This invention is 1liI! The present invention relates to a method for producing a titanium-containing composite carbonitride used as a raw material in producing a quality alloy.

<Prior Art> Conventional methods for producing titanium-containing composite carbonitrides include (1) a method in which titanium and other metal powders are mixed with carbon powder, and the mixture is treated at high temperature in a nitrogen-containing atmosphere.

+21 A method of mixing titanium and other metal carbides, nitrides, and carbide powders and treating them at high temperature in vacuum or in an atmosphere of hydrogen, nitrogen, inert gas, etc.

(3) A method in which titanium and other metal oxide powders and carbon powder are mixed and treated at high temperature in an atmosphere containing nitrogen.

is mainly carried out.

<Problems to be Solved by the Invention> However, each of the above-described conventional methods has the following drawbacks. That is, in method (1), it is extremely difficult to obtain fine particles of metal powder as a starting material, and even if such fine particles are obtained, the fine particles are active and difficult to handle. Not suitable for industrial use.

Therefore, only coarse-grained metal powder can be used, but in this case, the composite carbonitride to be prepared also becomes coarse-grained, and a long time is required for pulverization after treatment, which is not industrially practical.

In method (2), a considerably high temperature is required to form a solid solution of carbides, nitrides, and carbonitrides, making it impossible to coarsen the particles, and also requiring a long time for pulverization. Also.

In method (3), the oxide is usually fine and the resulting composite carbonitride is also fine and has good grindability, but solid solution progresses and
There is a problem in that only a mixture of carbides and nitrides (partly a solid solution) can be obtained.

<Means for Solving the Problems> As a result of intensive studies by the present inventors in order to eliminate the drawbacks of the above-mentioned conventional method, the present inventors have arrived at the improvement of the above-mentioned conventional method (3) in particular.

That is, in this invention, titanium and other metal oxide powders and carbon powder are used as starting materials, and after mixing these, a high temperature treatment is performed in a nitrogen-containing atmosphere to perform reduction and carbonitriding.

Next, the removed carbonitride is put into the mixer again, and simultaneously mixed and pulverized. This re-pulverized carbonitride is subjected to high temperature treatment in a vacuum or in an atmosphere of H2, Na, Ay, etc. to promote solid solution.

Effect> First, an oxide was used as a starting material in order to obtain a fine powder with good grindability.

A portion of the carbon is used to reduce the oxide and the remainder is used to carbonize.

In the first stage of high-temperature treatment, oxides are reduced, and carbonitriding progresses in parallel. It is essential at this stage that the atmosphere be nitrogen-containing.

This is because once carbonized, it is generally difficult to replace carbon in the carbide with nitrogen, and it is preferable to perform nitridation simultaneously with reduction and carbonization. Next, the obtained carbonitride is mixed again and pulverized. This process is performed to remove the oxide layer or carbon adsorption layer on the surface of the carbonitride, and at the same time destroy the carbonitride within its grains to expose a fresh surface. Method (3) of the above-mentioned conventional techniques does not have this process, so after carbonitriding, an oxidized layer or a carbon adsorption layer remains on the surface layer of each carbonitride, which inhibits solid solution. was.

Next, in the second stage of high temperature treatment, solid solution of carbonitrides is performed. Due to the above remixing process, the carbonitride surface is highly active and solid solution proceeds smoothly. Note that in this second stage high-temperature treatment, it is optional whether or not to use an atmosphere containing nitrogen. This is because a carbonitride containing nitrogen is obtained in the first stage of high temperature treatment, and there is no need for nitriding in the second stage. Therefore, the purpose of creating a nitrogen atmosphere in the second stage is to prevent nitrogen from escaping due to the decomposition of carbonitrides. Therefore, if there is no concern about denitrification, vacuum, H2
, b, co, etc., but an oxidizing atmosphere promotes oxidation of carbonitrides, which is not preferable.

<Example> The present invention will be explained below with reference to Examples.

Example 1 To create a solid solution powder of (Tjw)(C,N), T
= Mix Or powder, w□, powder, and C powder, P N2
The temperature was maintained at 1800°C for 1 hour in a nitrogen atmosphere of = 5ooyorr.

The obtained carbonitride was ball milled and then treated again under the same conditions.

For comparison, a sample was prepared that was subjected to the same treatment without the intermediate ball milling.

The compositional analysis results of each sample are shown in Table 1, and the x'm chart is shown in Figure 1.

As can be seen from Table 1 and the chart in Figure 1, the composition is almost unchanged, but the product of the present invention is sufficiently dissolved in solid solution, whereas the comparative amount is
It was observed that the Q peak remained.

Example 2 Various oxide powders and C powder were mixed and held at 1700° C. for 30 minutes in a nitrogen flow of 1 atm. The resulting carbonitride was ball milled and then heated to 0.01 Torr.
The temperature was maintained at 1600° C. for 1 hour in a vacuum of r.

A sample was also prepared which was subjected to the same treatment without ball milling.

Table 2 shows the composition of the obtained composite carbonitride and the ratio of the main peak of other carbonitrides to its main beam.

From the table above, it was found that the solid solution was significantly promoted by ball milling during the process.

Example 3 Samples having the same composition and the same first-stage treatment as in Example 1 were ground in a ball mill and held at 1800° C. for 1 hour in various atmospheres shown in Table 4.

When each sample of the composite carbonitride thus obtained was subjected to X-ray diffraction, it was confirmed that it was sufficiently dissolved in solid solution.

The I-component analysis results of the obtained samples are shown in Table 3.

Table 3 I found that it didn't make any noise.

However, when air was introduced, oxidation progressed, which was not desirable.

Example 4 Metals or carbonitrides were mixed to have the same composition as Sample No. 9 in Example 2, and heat treated to prepare a solid solution raw material. When these and Sample No. 9 were subjected to ball mill grinding for 24 hours and the grindability was examined, the particle size after grinding was as shown in Table 4, and it was recognized that the sample according to the present invention was finer. .

Table 4 Example 5 Using samples Nos. 9 and 10 of Example 2 and samples Nos. 23 and 24 of Example 4, Ni powder was added thereto, mixed in a ball mill, and press sintered to form a so-called cermet alloy. I made a prototype. The hardness and transverse rupture strength of each alloy obtained are shown in Table 5.

Table 5 Next, try cutting each of the above alloys under the following conditions! I did it. The results are shown in Table 6.

Condition 1 (continuous film m) Rigid material 845C ■ Tool F N IIR-44A chip S N G H120408 Speed
200m/1n depth of cut 2.0
ffil sending ri 0.30 am
/rev life judgment Ve = 0.311 #I condition 2 (intermittent turning) Work material SCM435 fully manned tool F N IIR-44A tip S N G H120408 Speed
100m/1iin depth of cut 1.51 Feed 0゜20i
m/rev time 1 minute Life judgment Number of defects in 20 cutting edges Table 6 <Effects of the invention> As detailed above, according to the present invention, a composite material with fine particles, good crushability, and good solid solubility. Carbonitrides can be obtained. When this composite carbonitride is used as a raw material when manufacturing hard alloys such as cemented carbide and cermet by powder metallurgy, an extremely fine-grained alloy can be obtained, which has high hardness and strength (X, so it is wear resistant). It has excellent heat resistance and fire resistance of 40%.

In addition, conventional Ti C, TL N 1W C, Mo 2C
Compared to the case where carbides and nitrides such as , Ta, C, etc. are mixed alone, the cost is lower and the energy consumption can be reduced.

[Brief explanation of drawings]

FIG. 1 is an X-ray diffraction chart of the solid solution powder obtained by Komei's method, and FIG. 2 is an X-ray diffraction chart of the solid solution powder obtained by the conventional method. Applicant's agent Patent attorney Ai 1) Showa 1st diffraction A2θ (deg) Fig. 2 diffraction within 20 (deg)

Claims (1)

[Claims] Titanium oxide and one or more oxides of group IVa, Va, and VIa metals excluding titanium are mixed with carbon, treated at high temperature in a nitrogen-containing atmosphere, and the resulting carbonitride is pulverized and mixed, followed by vacuum treatment. Alternatively, a method for producing a titanium-containing composite carbonitride characterized by high temperature treatment in a non-oxidizing atmosphere.