JPS6010099B2 - Method for manufacturing silicon carbide fiber reinforced nickel composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silicon carbide fiber reinforced composite material reinforced with silicon carbide fibers and a method for producing the same.

In recent years, along with space and ocean development, ultra-high temperatures, high pressures,
Materials that can withstand extremely low temperatures are needed, and there is a desire to strengthen metals with fibers, so metals are reinforced with alumina fibers, boron fibers, tungsten fibers, carbon fibers, etc. to create materials that can be used under the extreme conditions mentioned above. This has been attempted, and in some cases practical materials and used.

Conventional research and development on silicon carbide fiber-reinforced metal composite materials has focused on developing composite materials that use the silicon carbide whiskers to reinforce metal, since the silicon carbide fibers that are in practical use are in the form of whiskers. This is done regarding the materials.

Aluminum, iron, nickel, beryllium, cobalt, titanium, and the like are attracting attention as metal materials reinforced with silicon carbide fibers. Among these, nickel is a heat-resistant material and is promising as a matrix metal for fiber-reinforced metal composite materials. However, in silicon carbide whisker-reinforced composite materials, SIC and nickel react at temperatures above 100,000 to form a liquid phase; The shear strength between nickel and nickel decreases. Therefore, silicon carbide whisker-reinforced nickel composite materials have not yet been put into practical use.The present invention aims to address the drawbacks of the silicon carbide fiber-reinforced nickel composite materials. The purpose is to provide a practical silicon carbide fiber-reinforced nickel composite material that has high tensile strength and high modulus of elasticity at room temperature and high temperature, and a method for producing the same, and has zero free carbon.

When silicon carbide fiber containing 0.1% or more is combined with nickel, the free carbon easily diffuses into the nickel metal and forms a solid solution, so the carbon produced by the decomposition of SIC is absorbed into the nickel metal. The spread is suppressed ~ SIC
Since no decomposition reaction occurs, SIC and nickel do not react with each other, and carbide is generated from free carbon and nickel metal, improving the wettability or bonding between the fiber and the metal base, so that the fiber and the metal base do not react with each other. We newly discovered that the shear strength between nickel and silicon carbide fibers increases. It is a completed invention.

0.0% free carbon that can be used in the composite material of the present invention.
The silicon carbide fiber containing 0.01% or more is disclosed in Hakama Kosho No. 57-58891, for which the present inventors previously applied for a patent.
Special Publication No. 58-38534, Special Publication No. 57-53892, Special Publication No. 149925-1973, Japanese Patent Publication No. 1987-1499
No. 26, Special Publication No. 57-53893, Special Publication No. 57-56
This invention is based on the invention of No. 566. The reason for using silicon carbide fibers containing 0.01% or more of free carbon in the silicon carbide fiber-reinforced nickel composite material of the present invention is that even if the free carbon content is less than 0.01%, free carbon will diffuse from the silicon carbide fibers into nickel. Because the amount of nickel decreases, the reaction between the fibers and nickel cannot be suppressed, and the shear strength between the fibers and the metal base decreases, so the fibers and the metal base complement each other and increase the strength of the composite material. This is because the desired effect will be lost.

In the present invention, best results are obtained using silicon carbide fibers preferably containing 2 to 20% free carbon.

Using silicon carbide fibers with different amounts of free carbon,
The relationship between the tensile strength and elongation of the composite material obtained by combining it with nickel and the amount of free carbon is as shown in the wing diagram, ``As the amount of free carbon increases, the tensile strength of the composite material increases. , remains constant at around 14% i8%
When the strength decreases from around 20% or more, the effect as a composite material disappears. Even if the free carbon content is 2% or less, the effect as a composite material is small. On the other hand, the elongation of the composite material decreases as the amount of free carbon increases, and becomes extremely small at 20% or more.

It is therefore advantageous to use silicon carbide fibers containing 2 to 20% free carbon. The reason why the tensile strength of the silicon carbide fiber-reinforced nickel composite material of the present invention increases as the amount of free carbon in the fibers increases is as shown in the Ni-C phase diagram in FIG. The free carbon in the fibers diffuses into the nickel metal to form a solid solution, and when cooled, part of the carbon becomes carbide and precipitates on the fiber surface, and the other part dissolves in the nickel. ing.

The precipitated carbide binds the fibers and the metal base to increase the strength of the composite material, and the carbon dissolved in the nickel metal increases the hardness of the metal base to increase the strength of the composite material. Diffusion of the free carbon into nickel is easier than diffusion of carbon generated by the decomposition of S;C into nickel, so the free carbon increases the carbon concentration in nickel and the decomposition of SIC Because the diffusion rate of the generated carbon is suppressed, the reaction between SIC and nickel is suppressed, and ``SIC and nickel react with each other, such as in a silicon carbide whisker-reinforced nickel composite material consisting only of SIC, resulting in a decrease in shear strength.'' will disappear.

Furthermore, since the silicon carbide fibers and nickel react slightly at the interface, the wettability between the fibers and the metal matrix is improved, and this improves the wettability due to carbide formation.
It increases the shear strength and increases the strength of the composite material. However, as the amount of free carbon in the silicon carbide fiber increases, the amount of carbide produced increases, and the amount of carbon solidified on the metal matrix increases, resulting in a decrease in elongation. The tensile strength, elongation and modulus of the silicon carbide fiber reinforced nickel composite of the present invention vary depending on the volume percentage of silicon carbide fibers in the composite. That is, as shown in Figure 3, free carbon is
The tensile strength of silicon carbide fiber-reinforced nickel composite materials, which are made by changing the amount of composite silicon carbide fibers, increases as the amount of silicon carbide fibers increases, reaching 50% by volume. The tensile strength of nickel is approximately 2. He is now more than Hougo. However, as shown in Figure 4, the elongation of the composite material becomes smaller than that of nickel as the amount of silicon carbide fiber increases, and when the volume ratio exceeds 80%, the elongation of the composite material almost disappears. When the amount of silicon carbide fiber added is less than 2%, the tensile strength is almost the same as that of nickel.As shown in Figure 5, the elastic modulus of the silicon carbide fiber reinforced nickel composite material increases as the amount of fiber increases. The silicon carbide fiber-reinforced composite material of the present invention has excellent strength properties even at high temperatures, and when the content is 50% by volume, it is approximately three times that of nickel. As shown in Figure 6, the high-temperature tensile strength in an argon atmosphere of a silicon carbide fiber-reinforced nickel composite material containing 35% by volume of silicon carbide fibers containing 10% free carbon increases as the temperature increases. Although it decreases, the rate of decrease is smaller than that of nickel's tensile strength, and even with 90,000, it is about 80
It has a size of k9/mau and exhibits excellent high temperature properties.

In the silicon carbide fiber-reinforced nickel composite material of the present invention, when an element with a negative value is added to the matrix metal, the standard free energy change when reacting with carbon to form carbide is shown in Figure 7. It can be combined with silicon carbide fiber.

The added elements include chromium, molybdenum, manganese, silicon, niobium, titanium, aluminium, coir/alt, tungsten, nadium, tantalum, zirconium, calcium, and boron. These elements react with the free carbon in the silicon carbide fibers to create stable carbides. The carbide is generated on the surface of the silicon carbide fiber containing 0.01% or more of free carbon when the metal is brought into contact with the fiber at high temperature. The carbide formed on the surface of the fiber functions as a protective film that prevents the SIC from reacting with nickel and decomposing, and also functions to bond the silicon carbide fiber and the metal base. Therefore, it is advantageous for the production of composite materials to use an alloy in which nickel is added with the above elements as a metal base.One or more of the elements that tend to form carbides can be added to nickel. When making an alloy, even if you add iron and 8, which are thought to react with SIC,
Since silicon carbide fibers are protected by carbide, they can be added to the alloy in an amount of up to 50%.

However, when it exceeds 50%, the reaction with SIC becomes large and the shear state between the fiber and the metal becomes small. Carbon is an element that is advantageously added in small amounts to nickel and nickel alloys because it acts to inhibit the reaction between nickel and SIC. The element that generates the carbide, iron,
A nickel alloy that can be produced by adding one or more of copper and carbon to nickel to produce a nickel alloy, and from which a silicon carbide fiber-reinforced nickel composite material can be produced from a nickel alloy and silicon carbide fibers. Examples are shown in the table below.

table Next, the method for manufacturing the composite material of the present invention will be explained.

The silicon carbide fibers containing 0.01% or more of free carbon used in the present invention are as follows {1} to (10)
It is manufactured using organosilicon compounds classified as starting materials.

A compound containing only m Si-C bonds.

■Compounds that include Si-bonds in addition to Si-C bonds.

{3l Compound with Si-Side1 bond.

'4} A compound having a Si-N bond. ■ Si-O
A compound having an R (R-alkyl, aryl) bond.

[6} Compound having Si-OH bond.

{7) A compound containing an Sj-Si bond. '8} Si
-○-Si A compound containing a bond.

■Organosilicon compound esters. {10} Organosilicon compound peroxide.

Silicon and carbon are produced from at least one organosilicon compound belonging to the types {1} to (10) above by a polycondensation reaction using at least one of irradiation, heating, and addition of a polycondensation catalyst. An organosilicon polymer compound as a main skeleton component, for example, a compound having the following molecular structure is produced.

(b) (mouth) (c> 〇 A substance containing the skeleton component described in the above 'a) to 1 as at least one partial structure of a chain or three-dimensional structure, or a mixture of {a}, 'rho, shii' .

Examples of compounds having the above molecular structure include the following. n=1, poly(silmethylene siloxane) n=2, poly(silethylene siloxane) n=6, poly(silphenylene).

xane) (portion) n = 1, poly(methyleneoxysiloxane) n = 2, poly(ethyleneoxysiloxane) n = 6
, poly(phenyleneoxysiloxane) n = 12, poly(diphenyleneoxysiloxane) > n = 1, polysilmethylene n = 2, polysilethylene n = 3, polysiltrimethylene n = 6, polysilf enylene n=12, polysyldiphenylene Q containing the skeleton component described in [i] to 1 as at least one partial structure among chain, cyclic, and three-dimensional structures, or {i', 'd, Shiichi mixture.

The organosilicon polymer compound is spun, the spun yarn is preheated in vacuum or in an atmosphere of one or more selected from inert gas, CO gas, hydrogen gas, and hydrocarbon gas, and further in vacuum. Alternatively, silicon carbide fibers with extremely high strength and high elastic modulus can be produced by firing at a high temperature in the temperature range of 1000 to 2000 qo in an atmosphere of one or more selected from inert gas, CO gas, and hydrogen gas. can be manufactured. The reason why the firing temperature is set in the temperature range of 1000 to 2000 qo is that when firing at a temperature of 1000 qo or less, SIC in the fiber is
crystals are underdeveloped, fiber strength and elastic modulus are low, 20
This is because the decomposition reaction of SIC becomes more intense when it is more than 0,000. The ratio of silicon and carbon contained in the organosilicon polymer compounds of (a) to 6 above, which are the raw materials for the silicon carbide continuous fibers, is such that at least 5 atoms or more of carbon and 2 atoms of silicon are contained. Therefore, when this organosilicon polymer compound is graded and fired, most of the carbon bonded as side chains of the polymer will become hydrocarbons and volatilize, but at least 0.01% or more will be free. Carbon can remain in the silicon carbide fibers.The silicon carbide fiber reinforced nickel composite material of the present invention can be manufactured with zero free carbon.

This is carried out by forming a thin layer of silicon carbide fibers containing 0.01% or more, and filling the gaps between the fibers in the laminate with a liquid or solid metal base and bringing them into contact with each other to cause the free carbon to react with the base metal. be exposed.

In the above manufacturing method, when the S IJ concarbide fibers are brought into contact with the molten metal for a long time, the suppressed S
Because the reaction between IC and nickel progresses, the shorter the time for the melting contact, the better, and if it is usually within 1 hour, the free carbon in the fibers will react with the base metal, resulting in wetting of the L fibers and the base metal. The shear strength of the fiber and metal increases. Methods for compounding silicon carbide fibers with the molten metal include: [1] Molten metal infiltration method, ■ Casting method ~ {
3} There are three methods of tarikast method. Among these methods, the molten metal infiltration method is a method in which molten metal is infiltrated between aligned bundles of fibers in a vacuum or in an inert gas atmosphere.In this case, the molten metal is infiltrated using osmotic pressure, or It is also possible to evacuate and apply pressure to the molten metal side using an inert gas. '2) The casting method is a method of filling the spaces between the fibers with molten metal, similar to the molten metal infiltration method of {1), and is particularly useful as a continuous casting method. The fine die casting method is a method in which a mixture of fibers and molten metal is placed in a mold and pressure-molded. Next, the present invention will be explained with reference to examples.

Example 1 Nickel 74.0%, chromium 15.0%, molybdenum 6
．． A nickel alloy consisting of 0% titanium, 2.3% titanium, and 0.7% aluminum is placed in a chamber in an argon atmosphere and melted.

On the other hand, silicon carbide fibers containing 10% free carbon were placed in an array in an alumina tube with a diameter of 200 mm with both ends open.
One end was sealed, and the other end was connected to a vacuum system, and the alumina tube was degassed while being heated and placed in the argon gas chamber.The seal at one end of the alumina tube was removed in the argon gas chamber.
The same end was placed in the molten metal melt, and the alumina tube was evacuated to allow the molten metal to penetrate between the fibers. The molten state of the metal was maintained for 8 minutes to obtain a composite material. In this silicon carbide fiber reinforced nickel alloy composite material, 27
This tensile strength of 149k9 was approximately twice that of the boiled nickel alloy, and the nickel alloy could be reinforced with silicon carbide.Example 2 Nickel metal and free carbon 8 molten nickel was put into an alumina tube in the same manner as in Example 1 using silicon carbide fibers containing 1.0% and the molten state of nickel was maintained for 5 minutes to obtain a composite material.

This silicon carbide fiber-reinforced nickel composite material contains 27% fiber, and its tensile strength at 95 kg is approximately twice that of nickel. I was able to strengthen it. As described above, the silicon carbide continuous fiber-reinforced nickel or nickel alloy composite material obtained by the method of the present invention has extremely high tensile strength and high elastic modulus. Used as various materials.

(a) Materials for synthetic fibers, such as bobbins, separators, threaders, pump parts, sleeves, mechanical seals, valves, nozzles, hawkers, reaction vessels, pipes, heat exchangers, valves, etc.

(b} Materials for synthetic chemistry, such as plunger pumps
Sleeves, mechanical seals, separator t-reactor valves, pressure reducing valves, seats, heat exchangers, centrifugal separators, low temperature containers, etc.

[c} Materials for mechanical industry, such as heat exchangers, powder dies, ultrasonic processing machines, horns, sewing machine parts, cams, ball mill parts, camera parts, vacuum pump collectors, ball holders, tools, watch parts, machinery parts, etc. stand, etc.

'd} Materials for household goods and office supplies, such as desks, various shelves,
Yes, various lockers, etc.

'e} Materials for construction machinery, such as boring machines, rock drills, crushers, caterpillars, sand pumps, power shovels, and others.

m Disaster prevention parts, such as sprinklers, ladders, etc.

(cough) Materials for marine development (including space), such as heat exchangers, antennas, water markers, tanks, etc.

(1) Materials for automobiles, such as engine cylinders, flocks, cylinder heads, pistons, pulleys, rotary engines, etc. (i) Materials for food, such as super decanters, valves, reactors, mechanical seals, etc.
separators, etc.

(j) Sports materials, such as spikes, golf equipment, tennis rackets, fishing equipment, mountaineering equipment, ski equipment, badminton rackets, balls, etc.

and) Materials for ships and aircraft, such as engines, structural materials, external walls, screws, hydrofoils, etc.

0) Electrical materials such as power transmission cables, capacitors, chassis, antennas, stereo parts, balls, etc.

(m) Building materials, such as window frames, structural materials, etc.

(n) In addition to the above, materials for agricultural machinery, materials for fishing gear, materials for nuclear power, materials for nuclear fusion reactors, materials for solar heat utilization, materials for medical equipment, materials for bicycles, valves, valve seats, rings, combs, discs. , liners, inventers, pump parts for earth and sand transport, rock parts for waste disposal, dies for plastic extrusion injection,
It can be advantageously used for nozzles, reflectors, and others.

[Brief explanation of the drawings] Fig. 1 is a diagram showing the relationship between the amount of free carbon contained in silicon carbide fibers and the push and tensile strength of silicon carbide fiber-reinforced aluminum composite materials, and Fig. 2 is Figure 3 is a phase diagram of nickel and carbon, and Figure 4 is a diagram showing the relationship between the tensile strength of a silicon carbide fiber-reinforced nickel composite material containing 10% free carbon and the volume ratio of fibers in the composite material. Figure 5 shows the relationship between the elongation of a silicon carbide fiber-reinforced nickel composite material containing 10% free carbon and the volume ratio of fibers in the composite material. Figure 6 showing the relationship between the elastic modulus of a fiber-reinforced nickel composite material and the volume ratio of fibers in the composite material.
The figure shows the temperature change in the tensile strength of a silicon carbide fiber-reinforced nickel composite material containing 10% free carbon and the temperature change in the tensile strength of nickel. Figure 7 shows the standard free energy change in the carbide formation reaction. FIG. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. Spinning 1,000 to 2,000 times of an organosilicon polymer compound whose main skeleton components are silicon and carbon.
The silicon carbide fibers are baked at a temperature of 80 to 2% by volume and formed into silicon carbide fibers containing 0.1% or more of free carbon.
Volume % of nickel metal was heated and melted to fill the gaps between the fibers, causing a carbide-forming reaction between the free carbon in the fibers and the nickel base to improve the wettability between the silicon carbide fibers and the metal base. A method for producing a silicon carbide fiber-reinforced nickel composite material, characterized by: 2. Spinning from 1,000 to 2,000 spins made of an organosilicon polymer compound whose main skeleton components are silicon and carbon.
C. to obtain silicon carbide fibers containing 0.01% or more of free carbon, the silicon carbide fibers containing 80 to 2% by volume and a nickel alloy of 20 to 98% by volume as the alloy components. One or more elements selected from chromium, molybdenum, manganese, silicon, niobium, titanium, aluminum, cobalt, tungsten, vanadium, tantalum, zirconium, calcium, and boron, which are elements that react with carbon to form carbides. The nickel alloy base added with is heated and melted to fill the gaps between the filaments, and the free carbon in the fibers undergoes a carbide-forming reaction with the nickel alloy base, thereby improving the bonding properties between the silicon carbide fibers and the alloy base. A method for producing a silicon carbide fiber-reinforced nickel composite material characterized by improved