JPS62143875A - Manufacture of non-oxide sintered body - 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 Field of Industrial Application The present invention relates to a method for producing a non-oxide sintered body used as a cemented carbide tool or a high-temperature structural material.

Conventional technology Conventionally, non-oxide sintered bodies are produced by thoroughly pulverizing non-oxides synthesized by mixing metals or their oxides with non-metal element powders or solid non-metal elements and reacting at high temperatures. Also, it was manufactured by sintering under high temperature and pressure. This method requires a long (complicated) manufacturing process, is prone to contamination with impurities, and consumes a large amount of energy. Methods for producing sintered bodies have been proposed (e.g., B.D. Zabisianos and S.R. Morris).

Junior, Ceramic Engineering Society, Proceedings (P, D, Zavitsan
Osand J, R, Morris, Jr.
, Ceram, Eng, Sci, Pr
.

c, ), 4. [7-8], 624 (1983)).

This method involves thoroughly mixing powders of metal and nonmetallic elements (carbon and boron), forming them, and igniting a part of the compact under pressure to start a reaction, which leads to the synthesis and sintering of non-oxides. This is a method in which the formation of solid bodies is performed at the same time (referred to as the pressurized self-combustion sintering method).

Problems to be Solved by the Invention The sintered body produced by this method requires an ultra-high pressure of 3 GPa, and has a relative density (density of the sintered body/theoretical density) of 95% or less. Furthermore, mechanical properties such as hardness were slightly lower than sintered bodies made by conventional methods.
Oh Yamada.

Journal of the American Ceramic Society (Y, formerly Yamato, M, Koizumi a)
nd O, Yamada, J, Am, Ceram.
, Soc, ), 67, No, 11. C-22
4 (1984)') Means for Solving the Problems The feature of the present invention is that when a non-oxide sintered body is produced by a pressure self-combustion sintering method, a plate-shaped metal is used as a metal raw material, Another advantage lies in the fact that the plate-shaped metal is oriented.

According to the present invention, a high-density sintered body can be easily obtained by the pressurized self-combustion sintering method, so the sintered body is similar to or even higher than that of a conventional sintered body made using non-oxide powder. Machine (
A non-oxide sintered body with excellent strength can be produced with extremely low energy consumption.

Examples Example 1 As a starting material, the thickness is 10 μm, the length and width are 1 mm.
Using plate-shaped titanium and carbon black with a particle size of 0.1 μm or less, both were weighed out at a molar ratio of 1:1, mixed wet in hexane, and the mixture was mixed with Q, 5 nunXlOm.
A strip-shaped mixture in which plate-shaped titanium was oriented was obtained by extruding it from a mold having a rectangular nozzle with a size of m. This strip-like mixture was cut into appropriate lengths, stacked and pressed to obtain a columnar molded body with a diameter of 10mm and a height of 10mm. This molded body was subjected to pressure self-combustion sintering using a uniaxial pressure vacuum hot press using a mold made of silicon carbide rice. The molded body was ignited by energizing the tungsten filament. 10 samples
0°C-vacuum (10-' mmmm1l atmosphere・0.I
Under pressure conditions of GPa, the ignition heater was energized to start the reaction.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of titanium carbide was observed. Further, the relative density of this sintered body was 98.6'%. The structure of the sintered body consists of uniform tabular grains, and the length in the width direction is approximately 100 mm.
The length of μ11 in the thickness direction was 10 μm. The length in the thickness direction was approximately the same as the thickness of the titanium plate used as the starting material.

The Vickers hardness of the sample is 29 GN/ at a load of 500g.
It was. This value was the same as the hardness of a sintered body produced by a conventional method.

Example 2 As a starting material, 1 size: 30 μm, 1 vertical pattern, 0 horizontal lengths
, using a 5 mm plate-shaped titanium and carbon black with a particle size of 0.1 μm or less, weighing both at a molar ratio of 1:1,
A molded body was produced under the same conditions as in Example 1. This molded body was subjected to pressure self-combustion sintering using a uniaxial pressure vacuum hot press using a mold made of silicon carbide rice. The molded body was ignited by applying electricity to the tungsten filament.

The sample was heated at 100° C. in a vacuum (10=+nmt1g) atmosphere and at a pressure of 0.1 GPa, and the ignition heater was energized to start the reaction.

The obtained sintered body was subjected to X11i! When it was identified using diffraction, only the diffraction lines of titanium carbide were observed.

Further, the relative density of this sintered body was 99z.

The structure of the sintered body is composed of flat grains as in Example 1, and the length in the width direction is 100 μln and the thickness is approximately 25 μl.
It was m. This length in the thickness direction was approximately the same as the thickness of the titanium plate that was the starting material.

The Vickers hardness of Trial 1 is 28GN/ at a load of 500g.
n(was.

Example 3 Molar ratio of 1:1, thickness of 20 μm, length and width of 1
A sintered body of zirconium carbide was prepared in the same manner as in Example 1 using the same plate-shaped zirconium as in Example 1 and the same carbon black as in Example 1. However, under an argon atmosphere, 5
After heating to 00 °C, vacuum condition (10' nw Hz
) and ignited. In addition, the pressing force is 0.05G Pa
Met.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of zirconium carbide was observed. Further, the relative density of this sintered body was 98.7%. The structure of the sintered body was composed of plate-shaped grains as in Examples 1 and 2. The length of the axis in the width direction was 130 μm, and the length of the axis in the thickness direction was 20 μm.

This length in the thickness direction was comparable to the thickness of the zirconium plate used as the starting material.

The Vickers hardness of the sample is 26 GN/ under a load of 500g.
n? Met.

Example 4 Titanium boride was sintered in the same manner as in Example 1 using the same plate-shaped titanium as in Example 1 with a molar ratio of 1=2 and amorphous boron with a particle size of 0.1 μm or less. Created a body. however,
Room temperature, vacuum condition (10-' mm tl g ), 0.
It ignited under a pressure of 1 GPa.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of titanium boride was observed.

Further, the relative density of this sintered body was 99.4%.

The structure of the sintered body was composed of tabular grains as in Example 1. The length of this grain in the width direction is 30 μm, and the length in the thickness direction is 5 μo1. ) The length in the V direction is quite small compared to the thickness of the titanium plate from the starting material 1.

The Vickers hardness of the sample is 26ON/l at a load of 500g.
It was there.

Example 5 Zirconium boride was produced in the same manner as in Example 1 using the same plate-shaped zirconium as in Example 3 and amorphous boron with a particle size of 0.1 μm or less at a molar ratio of 1:2. A sintered body was created. However, at room temperature, in a vacuum state, with a sheet (10' mm)
tag), ignited under a pressure of 0.1 GPa.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of zirconium poride was observed. Moreover, the relative density of this sintered body was 99.2%. As in Example 1, the sintered body structure was composed of tabular grains.

The length of the grains in the width direction was about 20 μm, and the length in the thickness direction was 5 μm. This length in the thickness direction was considerably smaller than the thickness of the zirconium plate used as the raw material.

The Vickers hardness of the sample is 26 GN/ under a load of 500g.
It was ml.

Example 6 Example using plate-shaped titanium similar to Example 1 with a molar ratio of 1:1:2, titanium powder with a particle size of about 40 μm, and NoJ-bon black with a particle size of 0.1 μm or less. A titanium carbide sintered body was produced in the same manner as in Example 1. However, after heating to 200°C in an argon atmosphere, heating in a vacuum state (10-'mm
Hg), ignited under a pressure of 0.1 GPa.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of titanium carbide was observed. Further, the relative density of this sintered body was 99%. The structure of the sintered body was different from Example 1 and consisted of isotropic grains and tabular grains.

The grain size of the isotropic grains was 30 μm, and the diameter of the flat grains was 100 μm in the width direction and 10 μm in the thickness direction.

The bits hardness of the sample is 25 GN at a load of 500g.
#Met.

Example 7 Example 1 was prepared using plate-shaped zirconium similar to Example 3 in a molar ratio of 1:l:4, zirconium powder with a particle size of 30 μm or less, and amorphous boron with a particle size of 0.1 μm or less. A sintered body of zirconium boride was prepared in the same manner as described above. However, room temperature, vacuum condition (10'mmmm1l, O, lG P
It ignited under the pressure of a.

When the obtained sintered body was identified using X-ray diffraction, only the diffraction line of zirconium boride was observed. Further, the relative density of this sintered body was 98.5%. The structure of the sintered body was different from Example 1 and consisted of isotropic grains and tabular grains. The grain size of the isotropic grains is approximately 5 μm, and the width direction of the tabular grains is 20 μm and the thickness direction is 5 μm.
Met.

The Vickers hardness of the sample is 27 GN/ at a load of 500g.
n? Met.

Effects of the Invention According to the manufacturing method of the present invention, while pressure is applied to a molded body made of a mixture of oriented plate-shaped metals and nonmetallic elements, a part of the molded body is ignited at high heat and burned. A carbide sintered body can be produced simply by causing a reaction. Therefore, according to the manufacturing method of the present invention, a non-oxide sintered body can be manufactured with a much lower temperature process, that is, with extremely less energy, compared to the conventional manufacturing method using non-oxidized powder. Moreover, the obtained sintered body has properties that are the same as or better than those of sintered bodies produced by conventional manufacturing methods.

Claims (2)

[Claims] (1) A compact made of an oriented plate-shaped metal and a nonmetallic element is ignited under pressure to start a combustion process, and the heat generated as a result of the combustion process causes the metal and nonmetallic element to ignite. A method for producing a non-oxide sintered body, which proceeds with the reaction and sintering of the generated non-oxide. (2) Non-oxide sintering according to claim 1, characterized in that the combustion process is started under conditions in which a molded body consisting of an oriented plate-shaped metal and a nonmetallic element is pressurized and heated. Method for producing solids.