JPH01286970A - Nozzle for welding use - Google Patents

Abstract

PURPOSE:To obtain a nozzle with prolonged service life, by making the nozzle hole part with a specific titanium boride ceramic sintered form and the nozzle base with a material having its thermal expansion coefficient similar to that of said sintered form. CONSTITUTION:The objective nozzle to made up of (A) the nozzle base 12 fitted at the tip of feed pipe for welding gas and (B) the nozzle hole part 11 connected to said base 12, for heating and emitting said welding gas. The component B is made with a TiB2 ceramic sintered form <=5% in porosity, with a matrix layer 30 consisting of a solid solution from nickel boride and titanium carbide located among grains 20. The component A is made with a material having its thermal expansion coefficient similar to that of said TiB2 ceramic sintered form. The above constitution will sufficiently suppress the thermal strain to be developed between the components A and B in heating welding gas, leading to prolonged service life of said nozzle.

Description

Detailed Description of the Invention (1) Purpose of the Invention [Field of Industrial Application] The present invention relates to a welding nozzle, in particular, the nozzle hole is formed of a titanium boride ceramic sintered body, and the nozzle base is made of a boride ceramic sintered body. A welding nozzle made of a material with a coefficient of thermal expansion close to 8 of the titanium ceramic sintered body, and a protective layer formed of the titanium boride ceramic sintered body on the inner peripheral surface of the nozzle hole body. The present invention relates to a welding nozzle in which the nozzle hole main body and the nozzle base are made of a material having a thermal expansion coefficient close to that of the titanium boride ceramic sintered body.

[Prior art] Conventionally, this type of welding nozzle uses silicon nitride Sj:+
It has been proposed that a nozzle hole formed by sintering 1L or silicon carbide (SiC) is joined to a metal nozzle base.

[Problems to be solved] However, in conventional welding nozzles, the Vickers hardness and coefficient of thermal expansion of silicon nitride (Si3N) or silicon carbide (SiC) were smaller than those of the metal forming the nozzle base, so it When the temperature reaches a high temperature, thermal strain tends to occur between the nozzle and the metal forming the nozzle base, which has the drawback of not providing a long service life.

Therefore, in order to solve this drawback, the present invention forms the nozzle hole with a titanium boride ceramic sintered body and forms the nozzle base with a material having a coefficient of thermal expansion close to that of the titanium boride ceramic sintered body. A welding nozzle that suppresses and eliminates the thermal strain generated between the nozzle hole and the nozzle base when the welding gas is heated, as well as the inner part of the nozzle hole body connected to the nozzle base. A protective layer formed of a titanium boride ceramic sintered body is arranged on the circumferential surface, and the nozzle hole main body and nozzle base are made of a material having a thermal expansion coefficient close to that of the titanium boride ceramic sintered body. This suppresses and eliminates the thermal strain generated between the nozzle hole body and the protective layer when the welding gas is heated, as well as the thermal strain generated between the nozzle hole body and the nozzle base. The purpose is to provide a welding nozzle.

(2) Structure of the Invention [Means for Solving the Problems] The means for solving the problems provided by the present invention are as follows: In a welding nozzle comprising a nozzle hole for heating and discharging the welding gas, the nozzle is connected to a nozzle hole for heating and discharging the welding gas, wherein: (b) the nozzle base is formed of a titanium boride ceramic sintered body disposed between titanium boride particles and having a porosity of 5% or less; A welding nozzle characterized by being made of a material having a coefficient of thermal expansion close to .

Another solution to the problem provided by the present invention is as follows: ``a nozzle base attached to the tip of a welding gas supply pipe; (a) The nozzle hole has a nozzle hole main body connected to the nozzle base, and a mixture of nickel boride and titanium carbide. A solid solution matrix layer is disposed between titanium boride particles, is formed of a titanium boride ceramic sintered body having a porosity of 5% or less, and is disposed against the inner circumferential surface of the nozzle hole main body. and (b) the nozzle hole main body and the nozzle base are formed of a material having a coefficient of thermal expansion close to that of the titanium boride ceramic sintered body. This is a welding nozzle featuring the following.

[Function] The welding nozzle according to the present invention has a matrix layer in which a mixed solid solution of nickel boride and titanium carbide is disposed between titanium boride particles, and a boride having a porosity of 5% or less. The nozzle hole is formed of the titanium ceramic sintered body, and the nozzle base is made of a material having a thermal expansion coefficient close to that of the titanium boride ceramic sintered body, so the thermal expansion coefficient of the nozzle base is This acts to bring the 8wl tensile coefficient of the nozzle hole and the nozzle hole close to each other even when the welding gas is heated, and as a result, the thermal strain generated between the nozzle base and the nozzle hole when the welding gas is heated is sufficiently suppressed. As a result, it has the effect of achieving longer life.

Further, another welding nozzle according to the present invention includes a matrix layer in which a nickel boride and titanium carbide are mixed as a solid solution, or a titanium boride disposed between titanium boride particles and having a porosity of 5% or less. A protective layer formed of a ceramic sintered body is disposed on the inner peripheral surface of the nozzle hole body, and the nozzle hole body and the nozzle base have a thermal expansion coefficient close to that of the titanium boride ceramic sintered body. Since it is made of a material with a coefficient of It has the effect of sufficiently suppressing the thermal strain that sometimes occurs between the protective layer and the nozzle hole body, as well as the thermal strain that occurs between the nozzle base and the nozzle hole body, resulting in a longer service life. act to achieve.

[Example] Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a partial sectional view showing one embodiment of a welding nozzle according to the present invention, in which the nozzle hole 11 is formed of a titanium boride ceramic sintered body, while the nozzle base 12 is formed of a titanium boride ceramic sintered body. It is made of metal.

FIG. 2 is an enlarged sectional view showing the nozzle hole of the embodiment shown in FIG.

FIG. 3 is an optical micrograph showing the structure of the polished nozzle hole surface of the embodiment shown in FIG.

The case of Example 5 is shown.

FIG. 4 is a scanning electron micrograph showing the structure of the fractured surface of the nozzle hole in the example shown in FIG. 1, and shows the case of Example 5.

FIG. 5 is an optical microscope photograph showing the structure of the etched nozzle hole surface of the example of FIG.
The case is shown below.

FIG. 6 is a scanning electron micrograph showing the structure of the etched nozzle hole surface of the embodiment shown in FIG. 1, and shows the case of embodiment 5.

FIG. 7 is a graph showing the results of X-ray diffraction analysis performed on the nozzle hole of the example in FIG.
The horizontal axis represents the diffraction angle of X-rays, and the vertical axis represents the diffraction intensity of X-rays.

FIG. 8 is a scanning electron micrograph showing the structure of the fractured surface of the nozzle hole of the welding nozzle shown as Comparative Example 1.

FIG. 9 is a partial sectional view showing another embodiment of the welding nozzle according to the present invention, in which a protective layer formed of a titanium boride ceramic sintered body is provided on the inner circumferential surface of the nozzle hole main body 11^. The layer 11B is arranged, and the nozzle hole main body 11^
and the nozzle 21; m 1z is formed of metal.

First, regarding one embodiment of the welding nozzle according to the present invention,
Its structure and operation will be explained in detail.

In the welding nozzle of the present invention, F is a thermal expansion coefficient close to that of the nozzle hole 11 formed of the titanium boride ceramic sintered body and the thermal expansion coefficient ρ1 of the titanium boride ceramic sintered body, that is, there is no significant difference. It is made of a material such as a suitable metal (for example, brass) having a coefficient ρ2, and has a suitable mounting means such as a threaded portion 12A on its inner peripheral surface.
is formed and includes a nozzle base 12 connected at one end to a nozzle hole 11. Nozzle hole 11
The coefficient of thermal expansion p□ of the titanium boride ceramic sintered body forming the body and the coefficient of thermal expansion ρ of the material forming the nozzle base 12
If the ratio with 2 is 1/4≦ρ1/p2≦4.

preferable.

In use, the nozzle base 12 is attached to the tip of a welding gas supply pipe (not shown), and the welding gas supplied through the supply pipe is heated inside the nozzle hole 11 and the nozzle base 12 is heated at the tip S.
It is emitted from the opening towards the weld.

At this time, the nozzle hole portion 11 is formed of a matrix layer in which nickel boride and titanium carbide are mixed as a solid solution, or a titanium boride ceramic sintered body disposed between titanium boride particles and having a porosity of 5% or less. Since the nozzle hole 11 is formed of Accordingly, large thermal strain is not generated between the nozzle hole 11 and the nozzle base 12, and furthermore, the joint between the nozzle hole 11 and the nozzle base 12 is not damaged.

The welding nozzle base includes titanium boride TiB2 particles 20 and a mesh-like bonding layer 38 for bonding the titanium boride TiBt particles 20 in the structure of the nozzle hole 11.

The average particle size of titanium boride Ti8g particles 20 is 0.5~
10 p-m and a maximum particle size of 12 μm, especially an average particle size of 0.5 to 3 p-m and a maximum particle size of 6J411
The basis for setting the average particle size of the titanium boride Tie particles 20 to 0.5 to 10 lm is that (i
) If the average particle size is less than 0.51 Lm, the surface oxidation of the titanium boride TiBz particles 20 becomes noticeable, and the aggregation between the titanium boride TiBz particles 20 becomes noticeable, resulting in a reduction in the titanium boride according to the present invention. This will significantly inhibit the sintering of the ceramic sintered body, that is, the nozzle hole 11 of the welding nozzle base, and (ii) if the average grain size exceeds logm, the driving force for sintering will become small, which is not suitable for the present invention. It becomes difficult to make the nozzle hole 11 of the welding nozzle base densified, and the existing cracks in the titanium boride Ti8g particles 20 are enlarged.
The purpose of this is to reduce the strength of the material. In addition, the reason why the maximum particle size of the titanium boride TiB2 particles 20 is 12 μm is that if the maximum particle size exceeds 12 μm, it exists as coarse particles in the nozzle hole II of the welding nozzle base according to the present invention. One problem is that this prevents the nozzle hole portion II of the welding nozzle base according to the present invention from becoming denser or stronger.

A grain boundary phase 21 consisting of a mixed solid solution phase of titanium boride TiB2 and nickel boride NiJ is formed near the grain boundaries of the titanium boride TiBz particles 20. As a result, the bonding force between the titanium boride Ties particles 20 and the bonding layer 30 is made sufficiently large, and as a result, the strength of the nozzle hole U for welding nozzle wear according to the present invention is ensured. ing.

The bonding layer 30 is a boron formed by a reaction between nickel Xi, titanium boride TiB2, and carbon C such as TiBt+ 2Ni+ (:→2NiB + TiC or TiB1+ Ni +C+ NiBg + TiC or TiB, + 6Ni+C→2NiJ+ rfc). Kakinarashi i.e. nickel Ni
This is a matrix layer in which a boride such as NiB, NiB, or NiJ and titanium carbide (TiC) are mixed and dissolved in solid solution, and pores are sufficiently removed. As a result, the bonding force between titanium boride TiBz particles zO is said to be sufficiently large, and the porosity (i.e., the value obtained by dividing the pore volume by the total volume) published by Welding Nozzle is 5% or less. Because there are
As a result, the nozzle hole portion 1 of the welding nozzle fitting according to the present invention
1 density and strength are ensured. Here, the reason why the pores are substantially removed from the bonding layer, that is, the matrix layer 30, is that the particle size of the boride of nickel Ni, that is, nickel boride NiB, )iiB, or Ni, B, etc. and the particle size of titanium carbide TjC. Their diameters are almost the same, and they are homogeneously mixed and dissolved in solid solution.

Furthermore, regarding one embodiment of the welding nozzle according to the present invention,
The manufacturing procedure will be explained.

In the first step, a ceramic compound is created by blending titanium boride TiB powder, nickel Ni powder, and carbon C powder with each other at an appropriate blending ratio.

That is, (i) titanium boride TiB having an average particle size of 0.5 to 10 ILm (preferably 0.5 to 3 gm), a maximum particle size of 12 μm (preferably 6 pm), and a purity of 99% by weight or more; ii) The average particle size is 1 to 5 m (preferably 1 to 3 pm) and the maximum particle size is 12 pm (preferably 6 pm).
4m) of nickel Ni and (iii) specific surface area of 50~
150 m"/g (preferably 80-150 m"/g 27 g), purity is 99.9% by weight or more, and average particle size is 10-10
100 nm (preferably lO ~ 50 nm) with a maximum particle size of 15
0nm (preferably 10100n) of carbon (e.g. carbon black) are blended with each other to create a ceramic blend.In the ceramic blend,
8g of titanium boride Ti is 11 to 99.9% by weight (especially 75.0% by weight) to 0.1 to 89% by weight (particularly preferably 2.5 to 25.0% by weight) of the mixture of nickel Ni and carbon'XC. (preferably 97.5% by weight). The mixing ratio of nickel Ni and carbon C is 14=0.1 to 10 (particularly 14:0.2 to 5) by weight.
(preferably).

The reason why the purity of titanium boride TiB□ is 99% by weight or more is to avoid impurities from having an adverse effect during sintering.

The reason why the average particle size of nickel is 1 to 5 gm is that (i) if the average particle size is less than 1 gm;

The surface oxidation of the nickel Ni particles becomes noticeable, and the aggregation between the Nirakel Ni particles or the aggregation between the nickel Ni particles and the titanium boride TiBz particles or the carbon C particles becomes noticeable, and the welding nozzle according to the present invention This will significantly inhibit the sintering of the nozzle hole 11 of
) If the average grain size exceeds 5 uLm, coarse particles are present in the matrix layer 30 of the nozzle hole 11 of the welding nozzle according to the present invention or in the grain boundary phase 21 formed near the grain boundaries of the titanium boride Ti82 particles 20. Therefore, the strength of the nozzle hole 11 of the welding nozzle according to the present invention is reduced. The reason why the maximum particle size of nickel Xi is 12Bm is that the maximum particle size is 12p.
m, the existing agl is expanded to the nickel Ni particles, and the nozzle hole 11 of the welding nozzle arrangement according to the present invention
The purpose of this is to reduce the strength of the material.

In addition, the reason why the average particle size of carbon C is set to be 10 to 1100 nm is that (i) if the average particle size is less than 10 nm, surface oxidation of carbon C particles becomes noticeable, and aggregation between carbon C particles becomes noticeable. As a result, the welding nozzle pressure according to the present invention significantly inhibits sintering of the nozzle hole 11, and (
ji) If the average particle diameter exceeds 1 (lQ nm), the particles will exist as coarse particles in the matrix layer 30, which will reduce the strength of the nozzle hole 11 of the welding nozzle base according to the present invention. .Maximum particle size of carbon C is +5
The reason why it is 0 nm is that if the maximum particle size exceeds 150 mm, titanium carbide (TiC) formed by existing cracks in carbon C particles or reaction between titanium boride Tie.
The problem is that existing cracks in the particles are enlarged and the strength of the nozzle hole 11 of the welding nozzle pressure according to the present invention is reduced.

Furthermore, the reason why the specific surface area of carbon C is set to be 50 to 150 m2/g is as follows: (i) If the specific surface area is less than 50 m''/g, the carbon C particles are too large and cannot be used as titanium boride Tie. (ii) If the specific surface area exceeds 150 m''/g, the carbon C particles will aggregate with each other and the mixture with titanium boride, Tin, and nickel Ni. The problem lies in not being able to do anything.

In the second step, the ceramic mixture is homogeneously mixed using an appropriate mixer to create a ceramic mixture.

In the third step, the ceramic mixture is mixed with a binder (
For example, polyvinyl alcohol) is placed in an appropriate mold, and then the pressure is applied to an appropriate level (for example, 100 to 800 k).
A pressure of g/cm2) is applied to create a ceramic green compact.

In the fourth step, the ceramic green compact is subjected to CIP treatment, that is, room temperature isostatic compression molding treatment, by applying an appropriate pressure (for example, a pressure of 800 to 3500 kg/c layer 2) to form a ceramic compact.

In the fifth step, the ceramic molded body is placed in a vacuum atmosphere (preferably at an atmospheric pressure of 10-'Torr or less).
, in a non-oxidizing atmosphere (i.e., a neutral or reducing atmosphere) such as an argon atmosphere or a hydrogen gas atmosphere, in an unpressurized state or a pressurized state (100 to 500 kg
/cm2 pressure is applied) at a temperature of 1,500 to 2,000°C (preferably 1,600 to 1,800°C) for an appropriate time to obtain a ceramic sintered body. What is the basis for the non-oxidizing atmosphere here?

The purpose is to prevent titanium (Ti), boron (B), nickel (Ni), or carbon (C) from being oxidized.

In the sixth step, the ceramic sintered body is finished, that is, the inner surface of the nozzle hole 11 is mainly polished to a desired precision to form the nozzle hole 11 at a welding nozzle pressure.

In the seventh step, the nozzle base 12 is formed using a material such as a metal (for example, brass) having a coefficient of thermal expansion close to that of the nozzle hole 11 .

In the eighth step, the nozzle hole 1 is attached to the nozzle base 12.
1 are bonded together using a suitable adhesive (for example, an inorganic adhesive) to form a welding nozzle base.

Through the above steps, the welding nozzle base according to the present invention is manufactured.

In addition, an embodiment of the welding nozzle according to the present invention will be described using specific numerical values in order to facilitate understanding of the -layer.

Mixture 1 was prepared by changing the mixing ratio of nickel Ni with an average particle size of l#Lm and carbon black C with a specific surface area of 135 m''/g and a purity of 99% by weight. For 2.5% by weight, the average particle size is 3pm and the maximum particle size is 6JLm.
100 parts of a ceramic compound prepared by blending 97.5% by weight of titanium boride TiBz with a purity of 99% by weight was placed in a plastic container together with a urethane pole and 300 parts of ethylene alcohol, and was heated for 24 hours. A ceramic mixture was prepared by wet mixing.

The ceramic mixture was kept at a temperature of 60° C. for 10 hours to sufficiently dry it. Then ceramic mixture 100
The sample was placed in a suitable mold together with 2 parts of polyvinyl alcohol as a binder, and uniaxially pressed under a pressure of 100 kg/am'' to obtain a ceramic green compact.

The ceramic green compact was made into a ceramic molded body by applying a pressure of 3000 kg/Cs2 and subjecting it to CIP treatment, that is, room temperature isostatic compression molding treatment.

The ceramic molded body is heated to a temperature of 1700°C at a heating rate of 15°C/min in an unpressurized argon atmosphere and maintained at a temperature of 1700°C for 1 hour to form a ceramic sintered body. did.

The ceramic sintered body was finished, that is, the inner surface of the nozzle hole 11 was mainly polished to a desired precision, and the nozzle hole 11 was made into a welding nozzle.

In contrast, the nozzle base 12 was made of brass having a coefficient of thermal expansion close to that of the nozzle hole 11.

The nozzle hole 1■ and the nozzle base 12 are bonded together using an appropriate adhesive (
Here, they were bonded together using an inorganic adhesive to create a welding nozzle.

The total length of the welding nozzle was stated to be 651 mm, the opening at the tip of the nozzle hole 11 was 15 m1 in diameter, and the wall thickness was 0.25 mm.

Nozzle hole l of welding nozzle hole! and nozzle base 12
About Vickers hardness, flexural strength, porosity,! When the expansion coefficient and thermal conductivity were measured, they were as shown in Table 1.

In the welding nozzle, a welding gas supply pipe was attached to the nozzle X section 12, carbon dioxide CO gas was supplied as the welding gas, and the nozzle hole 11 was heated to 950° C. for welding. When used continuously in this condition, the welding nozzle could be used for 60 days (see "Life" in Table 1).
.

95% of titanium boride TiBg was added to 5.0% by weight of a mixture of nickel Ni and carbon black C on varnish 1t1 and 2U. Ofi amount%
Examples 1-7 were each repeated, except that only

Nozzle hole 11 and nozzle base 12 of the welding nozzle
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

(Examples 15-21) Examples 1-7 were repeated, respectively, except that 92.5% by weight of titanium boride TiBz was blended with 7.5% by weight of the mixture of nickel Ni and carbon black C. .

For example, in the case of Example 18 (the same applies hereinafter), the surface of the polished nozzle hole 11 was photographically observed using an optical microscope, and the results were as shown in FIG. 3, published by Welding Nozzle. That is, the bonding layer 3 is formed around the titanium boride particles 20.
It was found that the bonding layer 30 had no pores and was dense.

Welding Nozzle fractures the nozzle hole 11 with moderate force, and photographs the fractured surface with a scanning electron microscope H''!X
The results were as shown in Figure 4. That is, titanium boride Ti8. It was found that intragranular fracture occurred in the particles 20, and the titanium boride Ti81 particles 20 were firmly bonded by the bonding layer Ko0. Bonding layer 30
X-ray diffraction analysis revealed that the reaction between titanium boride Ties, nickel Ni and carbon black C resulted in nickel boride NiJ and titanium carbide TiC.
A matrix layer containing a mixed solid solution of (see Figures 5 to 7)
It turned out to be.

The outer surface of the welding nozzle was etched by immersing the nozzle hole 11 in aqua regia heated to 60'C for 3 minutes, and then photographed with an optical microscope, as shown in Figure 5. That's right. That is, the bonding of titanium boride Tin and particles 20 by etching treatment J! Titanium boride Ti8.J:10 was produced by falling off. By measuring the diameter of the particles 20, titanium boride Ti8
．． It was found that the average particle size of the particles 20 remained at 2 to 1 Opm. In other words, titanium boride Ti8. particle 2
It turned out that 0 had hardly grown compared to the beginning. This is because nickel Ni and carbon black C are
During sintering, TiBII+6Ni +c→2Ni, B+
This is because the Tic reaction occurs and the growth of the titanium boride Ti82 particles 20 is suppressed. Furthermore, X-ray diffraction analysis revealed that a grain boundary phase 21 consisting of a mixed solid solution phase of titanium boride Tie and nickel boride NiJ was formed near the grain boundaries of the titanium boride Ties particles 20. (See Figure 7).

Nozzle hole 11 and nozzle base 12 of the welding nozzle
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Mixture of nickel Ni and carbon black C on ±X onimatsu η2μ l000
Based on weight%, titanium boride TiB is 90.0 ball amount%
Examples 1-7 were each repeated, except that only

Nozzle hole 11 and nozzle base 12 published by Welding Nozzle
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Mixture of nickel Ni and carbon black C 12.5
87.5% by weight of titanium boride TiB*
Examples 1-7 were each repeated, except that only

Nozzle hole 11j5 and nozzle base 1 published by Welding Nozzle
When we measured the Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity of 2, we found that
It was as shown in the table.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Mixture of nickel Ni and carbon black C 15.0
Based on the weight%, titanium boride TiBz is 85.0% by weight.
Examples 1-7 were each repeated, except that only

Nozzle hole 11 and nozzle base 12 of welding nozzle fitting
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Mixture of nickel Xi and carbon black C on ±X nose garini V 17.5
82.5% by weight of titanium boride Tie2
Examples 1-7 were each repeated, except that only

Nozzle hole 11 and nozzle base 12 of welding nozzle bracket
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

(Examples 50 to 56) Mixture of nickel Ni and carbon black C 20.0
mm%, titanium boride Tiet was 80. Oi amount%
Examples 1-7 were each repeated, except that B.

Nozzle hole 11 and nozzle base 12 published by Welding Nozzle
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion a, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the lifespan of the "welding nozzle" was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Mixture of nickel Xi and carbon black C 22.5
Titanium boride TiB was 77.5% by weight.
Examples 1-7 were each repeated, except that only

Nozzle hole ll and nozzle base 12 of the welding nozzle
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the life of the welding nozzle plate was measured in the same manner as in Examples 1 to 7, and was as shown in the 1g41 table.

Mixture of nickel Ni and carbon black C 25.0
75.0% by weight of titanium boride TiB
Examples 1 to 7 were each repeated, except that the sintering temperature was 1500°C.

Welding nozzle worn out nozzle hole 21 and nozzle base 12
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 1.

Further, the life span of the welding nozzle was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Works Examples 1-7 were repeated, respectively, with the following exceptions:

Nozzle hole ill and nozzle base 12 of welding nozzle
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 71-77 were repeated, respectively, except that the sintering temperature was 1600°C.

Nozzle hole ll and nozzle base 12 published by Welding Nozzle
The Vickers hardness, bending strength, porosity, thermal expansion coefficient S, and thermal conductivity were measured, and the results were Σ as shown in Table 2, respectively.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 71 to 77, and was as shown in Table 2.

Technician Susuke 2±1 Examples 15-21 were repeated, respectively.

Welding nozzle worn out nozzle hole 11 and nozzle base 12
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 15 to 21, and was as shown in Table 2.

Examples 71-77 were each repeated, except that the sintering temperature was 1800°C.

Nozzle hole 11 and nozzle base 12 published by Welding Nozzle
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured, and the results were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 71 to 77, and was as shown in Table 2.

Examples 1-70 were repeated, except that the nickel Ni and carbon black C were removed from the L. Tsuga↓ top ceramic formulation.

That is, 100 parts of titanium boride TjB* having an average particle size of 3 gm, a maximum particle size of 6 gm, and a purity of 99% by weight,
A ceramic green compact was prepared by placing the powder in a suitable container together with 2 parts of polyvinyl alcohol as a binder, and uniaxially pressing it under a pressure of 100 kg/cm2.

The ceramic green compact was made into a ceramic molded body by applying a pressure of 300 kg/cm² and subjecting it to CIP treatment, that is, room temperature isostatic compression molding treatment.

The ceramic molded body is heated to a temperature of 1700°C at a heating rate of 15°C/min in an argon atmosphere without pressure, and maintained at a temperature of 1700°C for 1 hour to form a sintered ceramic body. And so.

The ceramic sintered body was finished, that is, the inner surface of the nozzle hole was mainly polished to a desired precision, and was used as the nozzle hole of a welding nozzle.

On the other hand, the nozzle base was made of brass having a coefficient of thermal expansion close to that of the nozzle hole.

The nozzle hole and the nozzle base were bonded to each other using an appropriate adhesive to create a welding nozzle.

The nozzle hole of the welding nozzle was broken with a moderate force, and the broken surface was observed in a photograph W1 using a scanning electron microscope, as shown in FIG. 8. That is, titanium boride Ti8. It was found that grain boundary fracture of the particles predominantly occurred, and the bonds between the titanium boride Tie particles were not very strong.

In addition, the Vickers hardness, flexural strength, porosity, thermal expansion coefficient, and thermal conductivity of the nozzle hole and nozzle base of the welding nozzle were measured, and the results were as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 1-7 were repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, it was as shown in Table 1.

Examples 8-14 were repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 15-21 were repeated, except that carbon black C was removed from the ceramic formulation on L.A.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 22-28 were repeated, except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 29-35 were repeated, except that Carbon Black C was removed from the L-Gloss A ceramic formulation.

Regarding the nozzle hole 3 and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 1.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Examples 36-42 were repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table 1.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Comparative Example Day Examples 43-49 were repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, pH expansion coefficient, and thermal conductivity were measured, and as shown in Table 1, each was S.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Example 50-56 was repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table 1.

Further, the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 1.

Examples 57-63 were repeated except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 64-70 were repeated, except that carbon black C was removed from the finish-glazed ceramics formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table 1.

Moreover, when the life of the welding nozzle was measured in the same manner as in Examples 1 to 7, the lifespan was as shown in Table 1.

Examples 71-77 were repeated except that the nickel Ni and carbon black C were removed from the finish-polished ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 78 to 84 were repeated, except that the nickel-based and carbon black C were removed from the El Shikitsuba concave ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 85-91 were repeated, except that the nickel Ni and carbon black C were removed from the polished ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 92-98 were repeated except that nickel Nig and carbon black C were removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 71-77 were repeated, except that carbon black C was removed from the ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

L ratio! Examples 78-84 were repeated except that carbon black C was removed from the rim ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 85-91 were repeated, except that carbon black C was removed from the ``Ninto Tsuyakoshi'' eceramics formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

Examples 92-g8 were repeated except that carbon black C was removed from the anti-mosquito ceramic formulation.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion a, and thermal conductivity were measured and were as shown in Table 2.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 2.

[Comparative Example 1 above was repeated except that the ceramic formulation was silicon nitride 5iJn.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and were as shown in Table 3.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 3.

Comparative Example 1 above was repeated, except that the ceramic formulation was silicon nitride, Si3N.

Regarding the nozzle hole and nozzle base of the welding nozzle,
The Vickers hardness, bending strength, porosity, coefficient of thermal expansion, and thermal conductivity were measured and found to be as shown in Table yS3.

Further, the lifespan of the welding nozzle was measured in the same manner as in Examples 1 to 7, and was as shown in Table 3.

As is clear from a comparison of Examples 1 to 98 and Comparative Examples 1 to 21 described above, according to the present invention, the matrix layer containing a mixed solid solution of nickel boride and titanium carbide in the nozzle hole is borated. Formed by a titanium boride ceramic sintered body disposed between titanium particles and having a porosity of 5% or less, and the nozzle base has a thermal expansion coefficient close to that of the titanium boride ceramic sintered body. By forming it with a material, thermal strain between the nozzle hole and the nozzle base due to heating of the welding gas can be sufficiently suppressed, and as a result, damage to the joint between the nozzle hole 11 and the nozzle base 12 can be prevented. can be avoided and, as a result, its lifespan can be greatly extended.

Next, the structure and operation of other embodiments of the welding nozzle according to the present invention will be described in detail.

As is clear from FIG. 9, this embodiment is different from the embodiments shown in FIGS. 1 to 7.

The nozzle hole body 11^ is formed from the same material as the nozzle base 12 and is appropriately connected to the nozzle base 12 by welding or the like to integrate the nozzle hole 11,
The protective layer 11B is formed of the above-mentioned titanium boride ceramic sintered body and is disposed on the inner circumferential surface of the nozzle hole main body 11A. The protective layer 11B is formed by sintering and then attached to the nozzle hole main body 11.
It may be arranged on the inner circumferential surface of the nozzle hole main body 11A, or it may be formed by sintering the ceramic mixture after disposing it on the inner circumferential surface of the nozzle hole main body 11A by coating or the like.

As for other specific effects, the composition range of the ceramic compound and the sintering conditions detailed in the above-mentioned examples are satisfied, and the titanium boride ceramic sintered body has a porosity of 5% or less. Although it has been confirmed that this can be achieved in the same manner as in the above-mentioned embodiment, a detailed explanation thereof will be omitted here for the sake of brevity.

(3) Effects of the Invention As is clear from the above, the welding nozzle according to the present invention has a nozzle base that is attached to the tip of the welding gas supply pipe, and a nozzle base that is connected to the nozzle base so that the welding gas A welding nozzle comprising a nozzle hole for heating and emitting nickel, in particular (a) the nozzle hole has a matrix layer in which a mixed solid solution of nickel boride and titanium carbide is borated (b) the nozzle base is formed of a titanium boride ceramic sintered body disposed between titanium particles and has a porosity of 5% or less; Since it is made of a material that has a coefficient of thermal expansion close to the coefficient of expansion, (i) even when heating the welding gas, the coefficient of thermal expansion of the nozzle base and the nozzle hole can be made close to each other. In addition, (ii) it has the effect of sufficiently suppressing the thermal strain that occurs between the nozzle base and the nozzle hole when heating the welding gas, and as a result (iii) it has the effect of extending the life. .

Another welding nozzle according to the present invention includes a nozzle base attached to the tip of a welding gas supply pipe, and a nozzle hole connected to the nozzle base for heating and discharging the welding gas. Particularly, (a) a nozzle hole main body in which the nozzle hole is coupled to the nozzle base.

A matrix layer containing a mixed solid solution of nickel boride and titanium carbide is disposed between titanium boride particles, and is formed of a titanium boride ceramic sintered body having a porosity of 5% or less, and the nozzle hole portion and (b) the nozzle hole body and the nozzle base have a thermal expansion coefficient close to that of the titanium boride ceramic sintered body. (i) Even when the welding gas is heated, the thermal expansion coefficient of the nozzle hole main body and nozzle base and the heat of the protective layer disposed on the inner surface of the nozzle hole water body are This has the effect of making the expansion coefficients closer to each other, and as a result, (ii) thermal strain that occurs between the nozzle hole body and the nozzle base and the nozzle hole water body when welding gas is heated. This has the effect of sufficiently suppressing the thermal distortion caused by the heat treatment, and as a result has the effect (iii) of extending the life.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the welding nozzle according to the present invention, FIG. 2 is an enlarged sectional view showing the nozzle hole of the embodiment in FIG. 1, and FIG. 3 is a polished version of the embodiment in FIG. An optical microscope photograph showing the structure of the treated nozzle hole surface, FIG. 4 is a scanning electron microscope photograph showing the structure of the fractured surface of the nozzle hole of the example shown in FIG. 1, and FIG. 5 is an etching image of the example shown in FIG. Optical micrograph showing the structure of the treated nozzle hole surface, Fig. 1
Figure 7 is a scanning electron micrograph showing the structure of the surface of the etched nozzle hole in the example shown in Figure 1.
A graph showing the results of line diffraction analysis, FIG. 8 is a scanning electron micrograph showing the structure of the fractured surface of the nozzle hole of the welding nozzle shown as Comparative Example 1, and FIG. 9 is a welding nozzle according to the present invention. FIG. 3 is a sectional view showing another embodiment of the invention. ”・・・・・・・・・・・・・・・・・・・・・Welding nozzle 11・・・・・・・・・・・・・・・・・・Nozzle hole 11A... ......Nozzle hole body tta...Protective layer 12...
・・・・・・・・・・・・・・・Nozzle base 20...
・・・・・・・・・・・・・・・Titanium boride particles 21・・・・・・・・・・・・・・・Grain boundary phase 3
0・・・・・・・・・・・・・・・・・・Matrix layer Fig. 1 Fig. 3 i C+4 m Fig. 1 Fig. 5 0 μm Fig. 6 Fig. 7 ○Ti82 TiC Angle Fig. 8 Fig. 9 +1A

Claims (3)

[Claims] (1) A welding nozzle comprising a nozzle base that is attached to the tip of a welding gas supply pipe, and a nozzle hole that is connected to the nozzle base and that heats and discharges the welding gas. (a) The nozzle hole is made of titanium boride ceramic, in which a matrix layer containing a mixed solid solution of nickel boride and titanium carbide is arranged between titanium boride particles and has a porosity of 5% or less. For welding, the nozzle base is formed of a sintered body, and (b) the nozzle base is formed of a material having a coefficient of thermal expansion close to that of the titanium boride ceramic sintered body. nozzle. (2) A welding nozzle comprising a nozzle base that is attached to the tip of a welding gas supply pipe, and a nozzle hole that is connected to the nozzle base and that heats and discharges the welding gas. (a) The nozzle hole body is connected to the nozzle base, and a matrix layer containing a mixed solid solution of nickel boride and titanium carbide is disposed between titanium boride particles. and a protective layer formed of a titanium boride ceramic sintered body having a porosity of 5% or less and disposed on the inner peripheral surface of the nozzle hole body, and (b) A welding nozzle, wherein the nozzle hole main body and the nozzle base are formed of a material having a thermal expansion coefficient close to that of the titanium boride ceramic sintered body. (3) The welding nozzle according to claim (2), wherein the nozzle hole main body and the nozzle base are integrally formed.