JPH03183754A - Heat resisting composite - Google Patents

Abstract

PURPOSE:To obtain high strength at high temp. and to stably use a composite over a long period by providing refractory metal fiber coated with Nb layer and Nb-Al alloy layer into a matrix composed of super alloy of Fe base, Ni base, etc. CONSTITUTION:A beat resisting composite is formed by providing refractory metal fiber into a matrix composed of Fe-base, Ni-base, or Co-base super alloy. Refractory metal fiber composed of tungsten alloy, etc., and coated with Nb layer consisting of Nb or Nb alloy and further coated with Nb-Al alloy layer on the above Nb layer are used as the above refractory metal fiber. In this heat resisting composite, thermal deformation can be prevented even if repeated thermal load between high temp. and ordinary temp. is applied. Since the surface of the Nb layer is coated with the Nb-Al alloy layer, mutual diffusion between the super alloy as matrix and the refractory metal fiber at high temp. can be prevented and, as a result, deterioration in a reinforcement consisting of the above refractory metal fiber can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) This invention relates to a heat-resistant composite having excellent strength at high temperatures.

(Prior Art) Recently, from the viewpoint of resource conservation, increasing the efficiency of large energy conversion devices such as gas turbines has become important.

A basic means of achieving higher efficiency is increasing the operating temperature of conversion equipment. In this case, the withstand temperature of the members used in the equipment poses a structural problem.

Traditionally, iron-based materials (
Fe group), cobalt group (Co group) or nickel group (N
Superalloys such as ip) are used. However, even with the use of these superalloys, the development of materials to increase the withstand temperature is nearing its limit.

Under these circumstances, composites made of the above-mentioned superalloys reinforced with refractory metal fibers are beginning to attract attention as next-generation heat-resistant materials. An example of this composite is one in which a tungsten wire (W wire), which is a refractory metal fiber, is embedded and integrated into a superalloy.

This composite is intended to combine the excellent high-temperature mechanical properties of W wire with the high-temperature corrosion resistance of superalloys. In such combinations of refractory metal fibers and superalloys, interdiffusion at high temperatures becomes a problem, but in order to solve this problem, W! I-reinforced Fe-based alloy composites have already been proposed.

However, even if this W-line reinforced Fed alloy composite is used, at high temperatures of 1100°C or higher, W
There is a problem in that the deterioration of the wire strength cannot be prevented, and in reality, the operating temperature of the conversion equipment is limited to 1000° C. or less. In addition, many refractory metal fibers, including W wire, have a smaller coefficient of thermal expansion than other metals, so when composited, it is impossible to avoid thermal stress caused by the difference in the thermal expansion coefficient of superalloys. Due to thermal stress, superalloys and W
There was a problem in that the wires became loose and sufficient high-temperature strength could not be obtained.

(Problem to be solved by the invention) This invention was made in consideration of the above points,
The purpose is to provide a heat-resistant composite that has sufficiently high strength at high temperatures and can be used stably for a long period of time.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention provides a superalloy base made of an iron-based, nickel-based, or cobalt-based superalloy, and a refractory metal disposed in the superalloy base. Provided is a heat-resistant composite comprising fibers, a niobium layer made of niobium or a niobium alloy covering the refractory metal fibers, and a niobium-aluminum alloy layer formed on the surface of the niobium layer. . When a cobalt-based superalloy or a nickel-based superalloy is used as the substrate, it is preferable to form a superalloy layer made of an iron-based superalloy on the niobium-aluminum alloy layer.

Such heat-resistant composites coat refractory metal fibers with a niobium layer made of niobium or niobium alloy, which has a coefficient of thermal expansion between that of refractory metal fibers and superalloys, so that they can withstand temperatures between high temperatures and room temperature. Thermal deformation can be suppressed even when subjected to repeated heat loads, and since the surface of this niobium layer is covered with a niobium-aluminum alloy layer, it is highly resistant to fire and nickel-based or cobalt-based superalloys as a matrix. Mutual diffusion with the metal fibers at high temperatures is prevented, and deterioration of the reinforcing body made of refractory metal fibers can be prevented. Therefore, this heat-resistant composite has sufficient high temperature strength.

The niobium-aluminum alloy layer acts as a barrier layer to prevent the diffusion of various elements from the nickel-based or cobalt-based superalloy matrix into the refractory metal fibers. This niobium-aluminum alloy layer can be formed by depositing a niobium-aluminum alloy on the surface of a niobium layer made of niobium or a niobium alloy.

From a practical point of view, an aluminum layer made of aluminum or an aluminum-based alloy can be formed on the surface of the niobium layer by vacuum evaporation method or PVD method (Ph1scal V
apor deposition), CVD method (Che
mlcal Vapor Deposltlon)
It is preferable to form a niobium-aluminum alloy layer at the interface between the niobium layer and the aluminum layer by heating the niobium layer after forming it by plasma spraying or the like to cause the niobium in the niobium layer to react with the aluminum in the aluminum layer. The heat treatment for forming the niobium-aluminum alloy layer may be performed by heating the refractory metal fibers after forming the aluminum layer, or when embedding the refractory metal fibers in the superalloy after forming the aluminum layer. This can also be done by heating. In this case, the thickness of the aluminum layer is preferably from 0.001 m to 0.05 m. If the film thickness is less than 0.001 am, an aluminum layer cannot be formed continuously on the niobium layer, and if it exceeds 0.05 s, the aluminum layer will crack or peel off.

The niobium layer is made of niobium or a niobium alloy,
It can be formed by applying powder such as niobium together with an organic adhesive to the surface of refractory metal fibers, and then integrating the fibers using a powder metallurgy method or by coating and integrating the fibers by plasma spraying. Here, as the niobium alloy, WSZ
r% Mo.

It is possible to use a material containing up to about 25 vt% of at least one of Hfs V and Ti5Y, with the remainder essentially consisting of niobium. The thickness of this niobium layer is preferably in the range of 0.01 mm to 0.1 ms. This thickness is 0.01m
If it is less than 1 g, the refractory metal fibers cannot be completely covered, and if it exceeds 0.1 g, the volume fraction of the refractory metal fibers decreases, and sufficient strength as a heat-resistant composite cannot be obtained.

The iron-based superalloy superalloy layer, along with the niobium-aluminum layer, functions as a barrier layer to prevent the diffusion of various elements from the nickel-based or cobalt-based superalloy into the refractory metal fibers. The thickness of this superalloy layer is 0.01 mm
A range of from 0.1 to 1 is preferable. This thickness is 0.01
If it is less than 0.1 mm, the niobium-aluminum layer on the surface of the niobium layer cannot be completely covered, and if it exceeds 0.1 mm, the volume fraction of the refractory metal fibers will decrease and the strength as a heat-resistant composite will not be sufficient. is not obtained. Such an iron-based superalloy is preferably an iron-based superalloy containing 20% or less of aluminum by weight. Specifically, the weight ratio is 1
0-35% Cr, 5-20% Al and balance Fe,
Alternatively, an iron-based superalloy having a composition of 20% or less Al and the balance Fe can be used.

This superalloy layer can be formed by thermal spraying, powder sintering, or the like. When a powder sintering method is used, a thermal spraying device, a CVD5PVD device, etc. are not required, and formation can be performed easily.

As the refractory metal fiber of the present invention, a refractory metal fiber made of tungsten, molybdenum, tantalum, or an alloy thereof can be used, but it is practically preferable to use a tungsten alloy.

In addition, in order to improve the high-temperature strength characteristics of refractory metal fibers, it is good to include 3 to 30 wt% of rhenium (Re), but if this content is less than 3 Vt%, no effect can be expected.
If it exceeds 30 wt%, the strength of the refractory metal fiber will decrease.

Furthermore, the strength of the refractory metal fiber can be further increased by doping the refractory metal fiber with any one of thorium oxide (ThO2), potassium, silicon, and aluminum. In the case of thorium oxide, this content is 0. It is in the range of 5vt% to 8wL%. Also,
When potassium, silicon or aluminum is used alone or in combination, the content is 50 ppm+ to 30
It is in the range of 0 ppm. Addition of ThO2 is expected to strengthen dispersion, but if it is less than 0.5 vt%, this effect cannot be expected, and if it exceeds 8 vt%, it will rather become a defect. K
-S l s All causes precipitation at grain boundaries and has resistance to recrystallization, so it is 50 to 300
This tungsten alloy, which cannot be expected outside the ppm range, is suitable because it is unlikely to undergo recrystallization, which causes strength deterioration at high temperatures of 1000° C. or higher. As for the dimensions of such refractory metal fibers, it is desirable that the lower limit is 0.1-1 in diameter from the viewpoint of handling, and the upper limit is 0.5-1 in terms of improving strength.

For nickel-based or cobalt-based superalloys as substrates, Cr s 5-20 with an fmffi ratio of 5-30%
% AI, 0.3-1.5% YSO ~ 30% Co,
Q~30% Fe and balance Ni,
and 5-35% Cr, 5-20% A, l! ,0.
A composition having a composition of 3 to 1.5% Y, 0 to 20% Ni, and the balance CO can be used. Further, as the iron-based superalloy as the base, the same material as the above-mentioned iron-based superalloy layer can be used.

The present invention also provides a superalloy base made of an iron-based, cobalt-based, or nickel-based superalloy, a refractory metal fiber disposed in the superalloy base, and a refractory metal fiber covering the refractory metal fiber made of niobium or a niobium alloy. The present invention provides a heat-resistant composite body characterized by having a niobium layer having the following properties and a ceramic layer coated on the surface of the niobium layer. When a cobalt-based superalloy or a nickel-based superalloy is used as the base, it is preferable to form a superalloy layer made of an iron-based superalloy on the ceramic layer.

Such heat-resistant composites have refractory metal fibers coated with a niobium layer made of niobium or niobium alloy, which has a coefficient of thermal expansion between that of refractory metal fibers and superalloys.
It is possible to suppress thermal deformation even when subjected to repeated thermal loads between high temperature and room temperature, and since the surface of this niobium layer is covered with a ceramic layer, the superalloy and refractory metal fiber as a matrix can be suppressed. Interdiffusion at high temperatures between the two is prevented, and deterioration of the reinforcing body made of refractory metal fibers can be prevented. Therefore, this heat-resistant composite is
Has sufficient high temperature strength. This ceramic layer acts as a barrier layer that prevents the diffusion of various elements from the superalloy matrix into the refractory metal fibers. Forming methods for coating the surface of the niobium layer made of niobium or niobium alloy with this ceramic layer include vacuum evaporation method, PVD method (Phfslcall Vapor Dep.
osltlon), CVD method (Chemical Va.
por deposition), plasma spraying, etc. can be used.

Alumina (All 203) is used as the ceramic layer.
, oxide ceramics such as silica (S i O),
Or aluminum nitride (Ai)N), silicon nitride (Si)
Nitride ceramics such as titanium nitride (T i N) and titanium nitride (T i N) can be used. The thickness of the ceramic layer in this case ranges from 0.001-1 to 0.001-1. (15 ms is preferable. If the film thickness is less than 0.OOlm-, a ceramic layer cannot be formed continuously on the niobium layer, and if it exceeds 0.05 s, the ceramic layer will crack or peel.

When the ceramic layer to be formed is an alumina layer and an iron-based superalloy layer or iron-based superalloy substrate is formed on this alumina layer, the niobium layer or iron-based superalloy may contain O and AI. or by heating the composite with O5 in one and All in the other,
An alumina ceramic layer can be formed between the niobium layer and the iron-based superalloy layer. Typically, the niobium layer is
is added to the iron-based superalloy, and AN is added to the iron-based superalloy and heated to form an alumina layer therebetween. That is, the following chemical reaction produces an alumina layer as a diffusion prevention layer (barrier layer).

2 [All] --p---allof + 3 [
01Nh→Af120s However, [1] , , , , 10. is AI contained in the iron-based superalloy layer. [01pib means O contained in the niobium layer.

The formation of an alumina layer as a diffusion prevention layer by heat treatment was first discovered by the inventors of the present invention after extensive research.

By using such a method, it is possible to reliably generate an alumina layer without using alumina aM by CVD, PVD, etc., which require advanced technology. Note that even when using a cobalt-based superalloy or a nickel-based superalloy as the base and not forming an iron-based superalloy layer, for example, by making the base contain Al and the niobium layer containing O and performing heat treatment, Similarly, a ceramic layer made of alumina can be formed. When the alumina layer is formed by heat treatment in this manner, the niobium layer and the superalloy are diffusion bonded as a result. This results in a composite with good interfacial bonding without compromising the mechanical properties of the refractory metal fibers, and, up to a significant volume fraction of refractory metal fibers, provides strength close to that expected from the composite. In particular, by using bulk FeCrA1 alloy as the superalloy, an extremely dense superalloy layer or substrate can be obtained.

As a superalloy substrate consisting of an iron-based, cobalt-based, or nickel-based superalloy, a compound represented by MCrAjlX (where M is N15FeSCo or an alloy thereof, or
is an oxide fixed element such as Y, Zr, Hf, etc.) can be used. As a compound represented by this MCrAjlX, 10 to 35 vt% Cr s 5 to 20 vt%
Ajl, 0.3-2.0w1% Y10-20vt%
FeCrAIY consisting of Ni and the balance Fe,
0-35 vt% Crs, 5-20 wt% AfI,
0.3-1.5vt% YSO-20vt% Ni, 0
Co consisting of ~30vt% Fes and the balance Co
CrAjpY or 10-40vt% Cr s 5-2
0 vt% Ajl, 0.3-1.5 vt% Y%O~
N1CrAIY consisting of 20 vt% CO10 to 30 vt% Fe and the balance NL is used.

As the iron-based superalloy layer, the same substrate as shown above can be used. Furthermore, the iron-based superalloy layer can be formed by thermal spraying, powder sintering, or the like, as described above.

In addition, as the refractory metal fiber and the niobium layer, the same ones as in the case of the first invention described above can be used.

(Example) Examples of the present invention will be described below.

Example 1 A tungsten wire with a diameter of 0.3 cm containing 1.7 wt % of thorium oxide was coated with a niobium layer of niobium having a thickness of Q (13 mm) by plasma spraying in a low-pressure atmosphere.

On this niobium layer, a coating made of aluminum with a thickness of 0.02 gv was formed by vacuum evaporation. This coating was coated by low-pressure plasma spraying with a thickness of 0.05 mg+, 24 wt% C', 8 vt%/l, 0.5 v
An iron-based superalloy consisting of t% Y1 and balance Fe was coated. Furthermore, on top of this, Q, 1 mm was applied by low-pressure plasma spraying.
with a thickness of 20 vt% COs and 16 wt% C
rs Coating a superalloy of N1CoCrANY consisting of 13 wt% All, 0.5 wt% Y1 balance Ni,
W/Nb/AD/FeCrAIY/N1CoCrAIY
A heat-resistant composite was obtained.

The obtained heat-resistant composite was heated to 1200°C for 5
After holding for 00 hours, a tensile test was conducted. the result,
This heat-resistant composite had a tensile strength of 210 kg/sm2, and it was confirmed that this tungsten wire had no strength deterioration and had sufficient high-temperature strength.

Example 2 0.3-■ diameter containing 1.7 vt% thorium oxide
Prepare 30 tungsten wires, arrange the tungsten wires in a line horizontally at intervals of 0.1 mm, fix them to a frame, and coat these tungsten wires with niobium to a thickness of 0.08-1 by plasma spraying in a low-pressure atmosphere. coated. Continuing,
Aluminum was coated to a thickness of 0.008 m by vacuum evaporation. Furthermore, by low pressure atmosphere plasma spraying,
with a thickness of 0.03 mm, 24 vt% C'', 8v
t% AN, 0. An iron-based superalloy consisting of 5vt% Y1 and balance Fe was coated. Furthermore, by low-pressure plasma spraying, it has a thickness of 0.15 mm and a COs content of 20 vt%.
16 vt% C', 13 vt% AD, 0.5
A sheet-like heat-resistant composite was obtained by coating a -''/Kel-based superalloy consisting of vt% Y1 with the remainder being Ni.Next, ten of these sheets were laminated with a Ni-based brazing material sandwiched between them. A heat-resistant composite was obtained by heat-treating in vacuum at 1200° C. for 15 minutes.The volume content of the tungsten wire in this heat-resistant composite was 30%.

The obtained heat-resistant composite has a density of 30 grains/llI2 at 1100°C.
It was found that the material had a creep rupture strength of 1300 fljl under a load of . Furthermore, it was confirmed that it did not deform even when subjected to a thermal load of reciprocating between room temperature and 1100°C ε more than 5000 times, and had sufficient high-temperature strength.

Example 3 0.311 diameter containing 1.7 vt% thorium oxide
A 1i tungsten wire was coated with a niobium layer having a thickness of 0.03 ain by plasma spraying in a low-pressure atmosphere, and on this niobium layer, a coating made of AgN with a thickness of 0.003 sv was formed by CVD. On this coating, a low-pressure atmosphere plasma melt 11=j I was applied with a thickness of 0.1 mm, and 2
4vt% of C', 8wt% of Ai!, 0.5wt
A heat-resistant composite was obtained by coating a superalloy substrate consisting of % Y1 with the remainder being Fe.

The obtained heat-resistant composite was heated to 1200°C for 5
After holding for 00 hours, a tensile test was conducted.

As a result, this heat-resistant composite had a tensile strength of 220 kg/ms7, and it was confirmed that this tungsten wire had no strength deterioration and had sufficient high-temperature strength.

Example 4 0.3 mm diameter containing 1.7 sit% thorium oxide
Thirty tungsten wires were prepared, and these tungsten wires were lined up horizontally in a row at 0.1 mm intervals and fixed to a frame, and these tungsten wires were coated with niobium to a thickness of 0.081 m by low-pressure plasma spraying. . Continuing,
Alumina (AIIzOs) was coated to a thickness of 0.01 mm. Furthermore, the thickness is reduced to 0.0mm by low-pressure atmosphere plasma spraying.
15 m5, 24 wt% Cr.

A superalloy substrate having a composition of 8vt% Al7 and 0.5vt% Y1 with the balance Fe was coated to obtain a sheet-like heat-resistant composite. Next, place these 10 sheets between them.
A heat-resistant composite was obtained by sandwiching and laminating the e-based brazing material and heat-treating in vacuum at 1200° C. for 15 minutes. The volume content of tungsten wire in this heat-resistant composite was 30%.

The obtained heat-resistant composite was heated to 30 kg/1 m2 at 1100°C.
It was found that the material had a creep rupture strength of 1,300 hours under a load of 1,300 hours. Furthermore, it was confirmed that the material did not deform even when subjected to a thermal load of reciprocating between room temperature and 1,100° C. 5,000 times or more, and had sufficient high-temperature strength.

Example 5 W with a diameter of 0.3 mm containing 1.7 sit% Th02
Thirty wires were arranged in a line at intervals of 0.1 cm and fixed to a frame, and the surfaces of these W wires were coated with a Nb layer having a thickness of 0.03 m5 by plasma spraying in a low-pressure atmosphere. Subsequently, this N
Plasma melt 1 (with a thickness of 0.5 mm) is deposited on layer b in the same manner as above.
A layer of O1+u+alumina (ANzOi) was coated. Further, on this alumina layer, a thickness of 0.03 m5 was applied by low-pressure atmosphere plasma spraying, and 24vt% C', 8w
t% AD, 0. A FeCrApY alloy layer having a composition of 5vt% Y1 and balance Fe was formed. Furthermore, F
0.15m thick by plasma spraying on eCrAIY layer
1, 20vt% COs 16vt% C',
13vt% Al, 0.5wt% Y, balance Ni
N1CoCrAj! having the composition of Form a Y alloy layer, W/Nb/Af
f 203 /FeCrAJ7 Y/N i CoCr
A heat-resistant composite sheet having a structure of AIIY and having a thickness of 0.75 gv was produced.

Next, 10 of these sheets were stacked with a Ni-based brazing material sandwiched between them, and heated in a vacuum at 1200° C. for 15 minutes to obtain a heat-resistant composite containing about 30% by volume of W wire.

This heat resistant composite was found to have a creep rupture strength of 1300 hours at 1100° C. under a load of 28 kg/-12. Also, the temperature between room temperature and 1100℃ is 500℃.
There was no deformation even when a heat load was applied over 0 cycles. Further, even when heated in the air at 1100° C. for 3000 hours, the W wires and Nb layer provided in the N1CoCrAjJY substrate were not oxidized.

As a comparative example, a Ni-based superalloy was prepared in which the same W wire as in the example was placed in a Ni-based superalloy using a refractory metal fiber coated with only an Nb layer. This heat-resistant composite had a creep rupture strength of 5 hours at 800''C under a load of 5)tgf/1ml'.

Example 6 FIG. 1 is a sectional view of the heat-resistant composite according to this example.

The heat-resistant composite 1 has a thickness of about 0.5-1, and includes a base body 2 made of an iron-based superalloy, and about 0.15 m in the base body 2.
It has 30 refractory metal fibers 3 which are arranged horizontally in a blind shape and embedded at intervals of -. These refractory metal fibers 3 are Th02 with a length of 10011% and 1.7vt%.
Tungsten fiber (1,7
Th02-W) was used.

A niobium layer 4 having a thickness of about 50 μm was coated on the surface of this tungsten fiber by low-pressure plasma spraying. Pure niobium powder was used as the niobium powder for thermal spraying.

When the partial pressure of oxygen gas in the thermal spraying atmosphere is adjusted to about the partial pressure of residual oxygen in a vacuum obtained with a normal oil rotary pump, niobium takes in oxygen during thermal spraying, and a niobium layer 4 containing 0 is obtained. It was done.

The iron-based superalloy substrate 2Q material includes Cr22vt%, A
FeCrA with an fI of 5.8 νt% and a balance of Fe
1 alloy was used. However, FeCrAj! The alloy was grooved with a rectangular groove about 0.15 sv deep and about 0.3 m wide. A tungsten fiber embedded in a niobium layer was placed in the groove and sandwiched between FeCrA1 alloys. Approximately 200 kg of this
4 at 1200°C in vacuum under a pressure of r/c1.
Diffusion bonding was performed by pressurizing and heating for a period of time. In order to obtain good diffusion bonding between FeCrAfI alloys as base materials, the FeCrAj7-containing CrA4 pretreatment includes polishing the FeCrAf1 alloy surface with 0.08 μm alumina grains in the air immediately before bonding. and then ultrasonic cleaning with acetone was sufficient.

Through the above process, an alumina layer 5 was generated at the boundary between the Nb layer 4 and the iron-based superalloy substrate 2 during diffusion bonding, and embrittlement of the tungsten fibers due to metal diffusion was prevented.

This heat-resistant composite 1 has a weight of 28 kgf'/1l at 1100°C.
It was found that the material had a creep rupture strength of 1000 hours under a load of 112 hours. Further, it did not deform even when subjected to a heat load of going back and forth between room temperature and 1100°C more than 3000 times. Note that since a bulk plate of FeCrA, Q alloy, which was originally dense, was used as the material, the iron-based superalloy layer 2 of the heat-resistant composite formed by this method was extremely dense.

As a comparative example, tungsten fiber similar to the example was
Using refractory metal fiber coated with a niobium layer that does not contain
A heat-resistant composite disposed in an iron-based superalloy similar to that of the example was created. In this heat-resistant composite, no anti-diffusion layer was formed and it did not exhibit any high-temperature high strength.

Example 7 FIG. 2(a) is a cross-sectional view of a heat-resistant composite according to this example,
(b) is an enlarged view of the refractory metal fiber portion. First, as the refractory metal fiber 13, 1.7vt% Th
Tungsten fiber (1
, 7Th02-W) 30 tungsten fibers were arranged in a row at 0.15 mm intervals and fixed to a frame, and the surface of these tungsten fibers was coated with a thickness of 0.03o+ by plasma spraying in a low-pressure atmosphere.
(2) Covered with niobium layer 14.

Pure niobium powder was used as the niobium powder for thermal spraying.

When the partial pressure of oxygen gas in the thermal spraying atmosphere is adjusted to about the partial pressure of residual oxygen in the vacuum obtained with a normal oil rotary pump, niobium takes in oxygen during thermal spraying, and a niobium layer 14 containing O is obtained. It was done.

Subsequently, the niobium layer 14 is coated with a film having a thickness of 0.05+u+ and 24 V by plasma spraying in the same manner as described above.
An iron-based superalloy substrate 2 made of an FeCrAfIY alloy having a composition of t% C, 8wt% AN, 0.5vt% yttrium, and the balance iron was formed to form a sheet.

Next, 10 of these sheets were stacked with a Ni brazing material 6 of about 0.01 mm thick sandwiched between them, and heated at 1200°C in a vacuum.
By performing the heat treatment for 15 minutes, a heat-resistant composite 11 containing about 30% by volume of tungsten fibers was obtained.

This heat-resistant composite was found to have a creep rupture strength of 1000 hours under a load of 28 kgf/2 at 1100°C. Also, the temperature between room temperature ε1100℃ is 300℃.
There was no deformation even when a heat load was applied over 0 cycles.

Example 1 PJ8 In this example, a heat-resistant composite having the structure shown in FIG. 1 was formed. Here, the heat-resistant composite 1 has a thickness of about 0.5 sec, and includes a base 2 of iron-based superalloy and a base 2 of about 0.5 sec.
It has 30 refractory metal fibers 3 embedded in a horizontal arrangement at intervals of 15 mg+. These refractory metal fibers 3 have a length of 100 mm and a T content of 1.7 vt%.
Tungsten fibers (1,77h02-W) containing hO2 and having a diameter of 0.3- were used. A niobium layer 4 having a thickness of about 50 μm was coated on the surface of this tungsten fiber by a vapor deposition method. As a vapor deposition material, about 10 at%
A mixture of niobium and niobium oxide was used, containing 0 of niobium.

Through this vapor deposition, a niobium layer 4 containing O was obtained.

The materials of the iron-based superalloy substrate 2 include Cr22wt%, A
f! A FeCrAff alloy with 5.8 wt % Fe in the spherical portion was used. However, the depth of FeCrAj7 containing CrA4 is approximately 0.151
A rectangular groove with a 1% width of about 0.3 mm was formed. A tungsten fiber embedded in a niobium layer is placed in the groove, and F
eCrAj! Sandwiched with alloy. This is approximately 200kgf/e
Diffusion bonding was performed by pressurizing and heating at 1200° C. for 4 hours in a vacuum under a pressure of 12°C. By performing diffusion bonding in this manner, it is possible to accurately form a heat-resistant composite with good arrangement of the refractory metal fibers and a high volume ratio of the heat-resistant metal fibers.

In order to obtain good diffusion bonding between FeCrAf1 alloys as base materials, the surface of the FeCrAf1 alloy is pretreated by polishing the surface of the FeCrAfI alloy with 0.06 μm alumina grains in the atmosphere immediately before bonding. It was sufficient to perform ultrasonic cleaning with acetone.

Through this process, an alumina layer 5 with a thickness of several μm was generated at the boundary between the Nb sprayed layer and the FeCrAl alloy, and embrittlement of the tungsten fibers due to metal diffusion was prevented.

This heat-resistant composite was found to have a creep rupture strength of 1000 hours under a load of 28 kgf/12 at 1100°C. Also, the temperature between room temperature and 1100℃ is 30℃.
There was no deformation even after applying a heat load of more than 00 cycles.

Note that since a bulk plate of FeCrA1 alloy, which was originally dense, was used as the material, the base material layer of the heat-resistant composite formed by this method was extremely dense. Further, the uniformity of the thickness of the niobium layer was also good.

Similar results were obtained when the shape of the groove was made into a 7-shape, a semicircle, or a U-shape instead of a rectangle.

Example 9 In this example, a heat-resistant composite having the structure shown in FIG. 1 was formed. Here, the heat-resistant composite 1 has a thickness of about 2 cm, and is embedded in a base 2 of iron-based superalloy and in this base 2, arranged horizontally at intervals of about 1 cm. It has five refractory metal fibers 3. These refractory metal fibers 3 have a length of 100mm and a diameter of 0 containing 1.7vt% The.
．． 3 mg of tungsten fiber (1,7Th02-W) was used. On the surface of this tungsten fiber, the thickness is approximately 0.
．． 5-1 powdered niobium layer 4 was coated. As for the material,
A powder of a mixture of niobium and niobium oxide containing about 10 at% 0 was used.

The materials for the iron-based superalloy layer 2 include 22wt% Cr, Al
FeCrAl1 alloy powder with 5.8 vt% remaining Fe was used. Diffusion bonding was performed by pressurizing and heating this in vacuum at 1200° C. for 4 hours under a pressure of about 200 kg f/cd.

Through this process, an alumina layer 5 was formed at the boundary between the niobium layer 4 and the FeCrAl1 alloy, and embrittlement of the tungsten fibers due to metal diffusion was prevented.

Example 10 FIG. 3(a) is a cross-sectional view of a heat-resistant composite according to this example,
FIG. 3(b) is an enlarged view of the refractory metal fiber portion. First, as the refractory metal fiber 23, a tungsten fiber with a diameter of 0.31 containing 1.7 vt% The2 (
1,7Th02-W), 30 tungsten fibers were lined up in a row at 0.15m5 intervals and fixed to a frame, and the surface of these tungsten fibers was coated with a low-pressure plasma spray to a thickness of 0.03+s.
It was coated with a niobium layer 24 of m. Pure niobium powder was used as the niobium powder for thermal spraying.

When the partial pressure of oxygen gas in the thermal spraying atmosphere is adjusted to about the partial pressure of residual oxygen in the vacuum obtained with a normal oil rotary pump, niobium takes in oxygen during thermal spraying, and a niobium layer 24 containing 0 is obtained. It was done.

Subsequently, this niobium layer 24 is coated with a film having a thickness of 0.05+ug and 24w by plasma spraying in the same manner as above.
An iron-based superalloy layer 22 was formed of a FeCrAIY alloy having a composition of t% Cr, 8wt% AlI, 0.5vt% yttrium, and the balance iron. All 30 refractory metal fibers embedded in the niobium layer 24 and the iron-based superalloy layer 22 thus obtained were subjected to low-pressure plasma spraying, and 20vt% Co and 16wt% Cr s were applied.
13vt% AN, 0. 5wt% Y1 balance Ni
A Ni-based alloy substrate 27 is formed of a N1CoCrAj1 alloy having a composition of W/N b/ Fe Cr
An Nll super superalloy sheet having a structure of AIIY/N1CoCrAfJY and a thickness of about 0.51 was prepared.

Next, 10 of these sheets were stacked with a Ni brazing material 26 with a thickness of about 0.01 m5 sandwiched between them, and 120
By performing heat treatment at 0° C. for 15 minutes, a heat-resistant composite 21 containing about 30% by volume of tungsten fibers was obtained.

This heat-resistant composite was found to have a creep rupture strength of 1250 hours under a load of 28 kgf/-2 at 1100°C. Also, the temperature between room temperature and 1100℃ is 30℃.
There was no deformation even after applying a heat load of more than 00 cycles.

The heat-resistant composite of the present invention includes core metal of a ceramic turbine blade which is a flat plate-like structure, heat-resistant bolts, nuts, and pins which are columnar structures, heat-resistant rope which is a linear structure, It can be used for applications such as heat-resistant pipes that are tubular structures.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a heat-resistant composite that has sufficiently high strength at high temperatures and can be used stably for a long period of time.

[Brief explanation of drawings]

1 to WS3 are diagrams showing a heat-resistant composite according to an embodiment of the present invention. 1.11.21...Heat-resistant composite, 2,12°27...
・Substrate, 3,13.23... Fireproof metal fiber, 4゜14
．． 24... Niobium layer, 5, 15.25... Ceramic layer, 22... Superalloy layer

Claims (6)

[Claims] (1) A superalloy base made of an iron-based, nickel-based, or cobalt-based superalloy, a refractory metal fiber disposed in the superalloy base, and a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber. and a niobium-aluminum alloy layer formed on the surface of the niobium layer. (2) A superalloy base made of an iron-based, nickel-based, or cobalt-based superalloy, a refractory metal fiber disposed in the superalloy base, and a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber. A heat-resistant composite body comprising: an aluminum layer made of aluminum or an aluminum alloy covering the niobium layer; and a niobium-aluminum alloy layer formed between the niobium layer and the aluminum layer. (3) a superalloy base made of a nickel-based or cobalt-based superalloy; a refractory metal fiber disposed in the superalloy base; a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber; A heat-resistant composite comprising: a superalloy layer made of an iron-based superalloy covering a niobium layer; and a niobium-aluminum alloy layer formed between the niobium layer and the superalloy layer. (4) a superalloy base made of a nickel-based or cobalt-based superalloy; a refractory metal fiber disposed in the superalloy base; a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber; a superalloy layer made of an iron-based superalloy covering the niobium layer; an aluminum layer made of aluminum or an aluminum alloy covering the niobium layer;
Niobium formed between the niobium layer and the aluminum layer
A heat-resistant composite comprising an aluminum alloy layer. (5) A superalloy base made of an iron-based, cobalt-based, or nickel-based superalloy, a refractory metal fiber disposed in the superalloy base, and a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber. and a ceramic layer coated on the surface of the niobium layer. (6) A base made of a nickel-based or cobalt-based superalloy, a refractory metal fiber disposed in the base, a niobium layer made of niobium or a niobium alloy covering the refractory metal fiber, and a surface of the niobium layer. 1. A heat-resistant composite comprising: a ceramic layer formed on the surface of the ceramic layer; and a superalloy layer made of an iron-based superalloy formed on the surface of the ceramic layer.