JPS60155579A - Ceramic-casted metal composite body and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite body of a ceramic sintered body and a cast metal, and a method for manufacturing the same, and more particularly to a composite body in which at least a portion of the casting is composed of a ceramic sintered body. The present invention relates to a ceramic-cast metal composite in which the ceramic sintered body constitutes the outer surface or inside of a casting, and a method for manufacturing the same.

In recent years, composites made by dispersing ceramic powder in various metals or reinforcing metals by mixing them with inorganic fibers have been proposed in order to obtain new materials having various properties suitable for various purposes of use.

However, the above-mentioned composites are generally homogeneous as a whole, and in many cases expensive ceramic materials must be used in areas other than high-temperature areas, sliding parts, or areas where corrosion resistance is particularly required. This was rather unreasonable, such as using excessive quality materials in unnecessary places.

Therefore, the present invention aims to utilize the characteristics of ceramics mainly for parts that require heat resistance, wear resistance, corrosion resistance, etc. in composites of various metals and ceramics, depending on the application. Only the sintered body is in contact with the other parts, and the other parts are made of various cast metals, so the ductility, strength, and workability characteristic of multimetallic materials are utilized as they are. To provide a ceramic-noxu cast metal composite having a structure that allows the use of ceramics and metals, and a method for manufacturing the same,
It is an object of this invention to overcome the above-mentioned disadvantages in the use of conventional composites.

Hereinafter, the composite of the present invention and its manufacturing method will be specifically explained.

According to the present invention, it is necessary that at least a portion of the casting is made of a ceramic sintered body.

The castings include cast iron castings, steel castings, copper or copper alloy castings, aluminum or aluminum alloy castings, zinc or zinc alloy castings, and cast iron castings, steel castings, copper or copper alloy castings, aluminum or aluminum alloy castings, and zinc or zinc alloy castings. It is preferable to use one or more of alloy castings, magnesium or magnesium alloy castings, tin or tin alloy castings. This is because these castings can be obtained from metals that are relatively inexpensive and easy to cast compared to ceramic materials. Note that the term "master alloy" as used herein refers to an alloy containing 50 or more metals serving as a matrix.

The above-mentioned cast iron is an iron alloy containing carbon, silicon, manganese, phosphorus, sulfur, etc. The most typical example is flake graphite cast iron, and these include ordinary cast iron and gray casting, and other strong iron alloys are used. There are 2 types of cast iron: 2) Alloy cast iron, 9) Spheroidal graphite cast iron, malleable cast iron, and chipped cast iron. Among these, ordinary cast iron and gray cast iron, which are flaky graphite cast irons, have a microscopic structure in which graphite is precipitated in flakes within other ferrite or pearlite, and the amount of carbon and silicon in the components has a large effect on the structure. It is preferable that the size and shape of the graphite as well as the condition of the ground change depending on the amount and proportion of the graphite. The reason for this is that this casting usually has good castability and is relatively cheap, and in conjunction with the above-mentioned good castability, it is easy to fit the ceramic sintered body during heat shrinkage, so a strong interfacial bond is created. This is because it is easy to obtain. Therefore, in the present invention, this casting is most often used. On the other hand, tough cast iron is made by reducing the amount of carbon and silicon in order to increase the strength of ordinary cast iron, and is characterized by having small graphite. Therefore, it can be used as a composite material suitable for applications requiring relatively high heat resistance and strength as a heat-resistant structural material, but it also has the drawback that it is difficult to cast compared to the above-mentioned ordinary cast iron.

Alloy cast iron is made by adding alloying elements to improve the properties of the cast material by refining graphite and stabilizing the ground. There is. The additive alloys mentioned here are chromium,
These elements include nickel M, copper, molybdenum, vanadium, titanium, etc., and by adding these elements, the heat resistance, abrasion resistance, corrosion resistance, machinability, etc. of the composite can be improved. Therefore, applications where heat resistance is required not only for a part of the composite but also for the whole, such as a part of a turbine blade, a part of a turbocharged rotor nut, or a mechanical seam,
Noz I.

It is suitable as a composite used for lining materials, etc. On the other hand, spheroidal graphite cast iron is manufactured by adding magnesium, calcium, cerium, etc. to the molten metal to precipitate spheroidal graphite, and is also called ductai M.
It has high strength and toughness, and is superior in heat resistance and wear resistance to flake graphite cast iron.In addition to being used as a composite as cast, it can be annealed like malleable cast iron to further improve its toughness. It can also be improved. Furthermore, chilled cast iron has a structure in which white pig iron is deposited on the surface and graphite is precipitated inside, and the surface is wear-resistant and the inside is tough. Therefore, as shown in the perspective views of Figures 1 and 2, it is advantageous to form a composite body in which a rod-shaped ceramic sintered body (2) or a tubular body (3) is fitted inside a casting α). be. The reason for this is that chilled cast iron has graphite precipitated in its internal structure, forming a nine-structure structure, so it is easily compatible with the surface of carbide-based ceramic sintered bodies, such as silicon carbide, boron carbide, and carbon crystal graphite, and is compatible with metals and ceramics. This is because the bonding at the interface with the material becomes better. In the composites obtained in this way, those with rod-shaped objects (■) fitted inside have a ceramic core part that has high hardness and wear resistance like silicon carbide or silicon nitride, and also has carbonized Materials with excellent lubricity and heat resistance, such as boron and graphite, have good sliding properties, so they are suitable for bearings, mechanics, and dies.

A tubular object suitable for use as a nozzle etc. (3)
Those made of silicon carbide are suitable for applications such as corrosion-resistant pipes.

Furthermore, cast steel can be broadly classified into carbon steel and special steel, and the lower the carbon content, the lower the tensile strength, the higher the elongation, the higher the equilibrium value, and the better weldability. Therefore, as shown in the longitudinal cross-sectional view of Figure 3, one side, that is, the steel shell side of the furnace (a) and the steel frame road side of the chemical plant (b), is made of cast steel, and the other side, that is, the inner wall of the furnace and the chemical reaction tank, is made of cast steel. The inside is made of a sintered body made of plate-like materials such as silicon carbide and silicon nitride with excellent corrosion resistance and heat resistance (4)
If so, it is advantageous. The reason for this is that cast steel, which has a metal surface, can be easily joined using simple methods such as welding, and positioning and installation can be done quickly and easily. has excellent corrosion resistance such as heat resistance and chemical resistance, and especially in the case of composites using silicon carbide sintered bodies, it has excellent oxidation resistance up to a high temperature range of 1400°C or higher, and is resistant to most strong acids, This is because it has extremely stable properties even against strong alkali. Therefore, it is possible to construct chemical plant linings with excellent durability that cannot be obtained with conventional metal materials. Since composites of cast steel and ceramics can be obtained relatively inexpensively, they are suitable for machine parts, such as machine tools, various modes, valves, etc., but castability is somewhat poorer than that of cast iron. Therefore, when manufacturing such a composite, it is necessary to
As shown in the explanatory diagrams (A) to (E) of the figure, the parts where the ceramic sintered body comes into direct contact with the cast steel are plate-shaped or flat-shaped objects with various shapes of uneven parts (C). The mechanical bond at the interface can be made even stronger by using . Furthermore, a ceramic sintered body having many pores may be used in place of the uneven portion (C). In this way, the bonding force can be improved by the mechanical fitting force as an anchoring effect due to the unevenness, and the relationship between the surface roughness and the wetting contact angle improves the castability, and the heat shrinkage of the metal The fitting performance and the compatibility between the two are improved, and the wetting of molten metal is particularly good due to capillary action.

According to the present invention, it is a composite of copper, aluminum, magnesium, zinc, nickel V, tin, alloys thereof, or composite alloys having two or more of these as a mother alloy, and various ceramic sintered bodies. You can also do that.

Copper alloy castings include bronze, brass, and aluminum bronze.Since these have a melting temperature of about 1000°C, they are lower than iron alloys and have good castability as well as ordinary cast iron. It has excellent corrosion resistance and wear resistance, and is suitable for various mechanical parts such as bearings, mechanical M sea 7L/, nozzles,
Suitable for parts such as corrosion-resistant pumps. Also precision measuring instrument parts, machine tools, and decorative items.

It can also be used as a leisure item.

On the other hand, MK aluminum, an alloy with improved mechanical properties by adding iron, manganese, nickel metal, etc., and aluminum bronze are alloys of copper, aluminum, and other alloys that have excellent wear and corrosion resistance. Composites with ceramic sintered bodies with excellent wear resistance and corrosion resistance, such as sintered bodies, are particularly suitable for various uses such as bearings, mechanical seats A/, nozzles, corrosion resistant linings, and corrosion resistant nozzles M. .

In addition, there are other light alloy castings such as amminilam alloy castings and magnesium alloy castings, and composites of these light metal alloys and relatively low-density amminiram sintered bodies (alumina sintered bodies) are lightweight. Because it has excellent heat resistance, it is suitable for applications such as heat exchangers, high-temperature jigs, and impeller reaction tubes.It also has good dimensional stability and excellent workability, so it can be used in complex shapes and high It can also be used for parts such as precision measuring instrument parts and turbine blades that require precision. In this regard, aluminum alloy castings and ceramics have improved mechanical properties by adding alloying elements such as copper, silicon, magnesium, manganese, and nickel, since aluminum alone has poor castability and poor mechanical properties. It is advantageous to form a complex with

In addition, magnesium alloys are more advantageous than the aluminum alloys in producing lightweight composites, and generally alloys containing aluminum, manganese, beryllium, etc. are used.

Other alloy castings include a die-casting alloy made by adding a small amount of amminilum to zinc, a nickel alloy called Monel Remeta 1, which is made by adding copper to nickel, and Hastelloy, which is made by adding molybdenum, chromium, and silicon.
Furthermore, it is an alloy made by adding copper and tin to lead.

A bearing alloy containing copper or antimony or an alloy containing copper or antimony added to tin can also be used as a casting. However, by combining the properties of these alloys with various ceramic sintered bodies, they can be used for automotive parts such as transmission cases, cylinder blocks, e-inlet manifolds, pumps, and camera bodies.

It can be used as a composite for various purposes such as instrument cases and covers.

On the other hand, according to the present invention, silicon carbide, boron carbide, silicon nitride, aluminum nitride, boron nitride, titanium nitride, and amminilum oxide are used as the ceramic sintered body.

It is preferable to use one or more of various materials having excellent properties such as sialon, zirconia, ferrite, cordierite, and graphite.

This is because these ceramic sintered bodies have excellent properties that make them suitable as heat-resistant structural materials, wear-resistant materials, and corrosion-resistant materials. However, according to the present invention, ceramic sintered bodies other than those exemplified above can also be used.

That is, the various ceramic sintered bodies used in the present invention are sintered bodies using various ceramic raw material fine powders.

Various materials can be used as the ceramic raw material fine powder, but among them, it is preferable that the main component is at least one selected from carbides, nitrides, oxides, or compounds thereof. For example, silicon carbide, boron carbide, aluminum carbide, tungsten carbide, titanium carbide, tantalum carbide, zirconium carbide, and nitrides include silicon nitride, boron nitride, aluminum nitride, titanium nitride, tungsten nitride, di-I nitride, etc.
Reconium, oxides such as steatite and forsprite.

Alumina, zircon, beryllia, magnesia, mullite, cordierite, aluminum titanate, zirconia, etc. can be used.

In the present invention, the ceramic fine powder has an average particle size of 2
It is preferable that the powder be a fine powder of μm or less.

Ceramic powder with an average particle size as large as 2 μm has relatively few contact points between particles, and conventionally known lubricants can sufficiently improve the formability, but the powder has poor sinterability, so it is difficult to achieve high density. This is because it is difficult to manufacture a sintered body of.

Next, an example of the method for manufacturing the ceramic-cast metal composite of the present invention will be described.

FIG. 6 is a longitudinal cross-sectional view of a mold suitable for manufacturing the composite of the invention. An example of the method for manufacturing the composite of the present invention will be explained below based on FIG. 6. In this drawing, a ceramic sintered body (4) is temporarily fixed to any part of a mold 6), for example, to the bottom part. Temporary fixation here refers to a fixed state that does not easily move when molten metal is cast, and refers to a fixed state that allows it to be separated from the mold after casting. As an example of temporary fixation, various shapes of keren (6
), and there is also a method of temporarily bonding one side of the ceramic sintered body to the mold with a binder. Keren is a metal fitting that supports the core, and is also called a mold holder, and can be of various shapes such as rod, drum, dragonfly, basket, or hat shapes. Select one that meets the following conditions, and preferably one made of the same metal as the casting. Also, it is advantageous to always cleanly polish the surface of the keren before use. This is because if oxides or moisture adhere to the surface of the coating, it will not only hinder welding but also cause cavities. On the other hand, a part of the ceramic sintered body is temporarily bonded to the surface of the mold using various binders such as diacrylate, cement, furan resin, 7-dinol resin, drying oil, or clay. It can also be temporarily fixed. After the ceramic sintered body is temporarily fixed in any part of the mold in this way, molten metals of the various metals mentioned above are poured through the sprue (7). Here, the shape and size of the sprue (7) are not limited at all, but it is advantageous to have a shape that allows the molten metal to flow quietly into it. Generally, gravity is used to pour the molten metal, but as a special method, there is a method of applying pressure to the molten metal during or after pouring. The die casting method is a method in which molten metal is injected into a mold under high pressure, and this method is used to manufacture a composite body made by joining a relatively thin casting and a ceramic sintered body in the form of a plate. suitable for In addition, the low-pressure casting method is a method in which a pressure slightly higher than atmospheric pressure is applied to the molten metal surface in the furnace, and the molten metal is pushed up into the mold through a tube. On the other hand, the centrifugal casting method is a method in which molten metal is poured into a mold while it is rotating, and the molten metal is pressurized using centrifugal force to create a casting. It is a composite body in which a ceramic sintered body is fitted into a sintered body, and is suitable for casting long objects such as pipes and gutters.

After casting in this way, remove the casting from the mold,
Remove any sand or dirt adhering to the casting, and remove any debris that overhangs from the sprue or the boundary between the molds. In this way, in addition to performing various post-treatments as necessary, the surface of the composite is ground or polished, cut into various shapes, and finished according to the purpose of use. Finally, we visually inspect the external appearance and presence of defects, and use ultrasonic flaw detection equipment and radiation equipment to check for internal defects.

Various types of furnaces are used to melt the above-mentioned metals, for example, Keepola or low-frequency induction electric furnaces are used for cast iron, electric arc heating electric furnaces and high-frequency induction furnaces are used for cast steel, and M is used for copper alloy and light alloy castings. It is advantageous to use a pot furnace. The reason for this is that it is possible to obtain the most economical and high-quality molten metal for each of these materials. - The mold is generally made by hardening sand with a binder, but it is also possible to use a green mold, a self-hardening mold (phenol resin type), or metal in addition to sand.

The most typical embodiments of the present invention will be described below.

Example After assembling a green mold or self-hardening mold (5) as shown in Fig. 6, a ceramic sintered body (4) with a plate-like thickness of about 3'Mk and vertical and horizontal A silicon carbide sintered body (product name ``IBICERAM'') with dimensions of 60 x 43 m was temporarily fixed in a cast iron keren (6), and the casting temperature was 1400±.
Ductai p was cast at 20°C. It has been newly discovered that preheating the ceramic sintered body at about 400°C is an effective means of mitigating thermal shock during casting.

When a brick-like composite consisting of the silicon carbide sintered body and Ductai V thus obtained was used to construct a liner for lining a chemical plant, ib had extremely excellent heat resistance, corrosion resistance, and It exhibits wear resistance and is several times more durable than a single ductile liner.

As described above, the present invention has excellent workability and workability that take advantage of the characteristics of various ceramic sintered bodies and metals, and also has properties that cannot be obtained by metal properties alone such as heat resistance, corrosion resistance, and wear resistance. It is possible to obtain a novel composite material that has never been used before, thereby expanding new uses, and at a relatively low cost, it is possible to easily obtain a composite material having various properties.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views of the composite of the present invention, Figure 3 is a longitudinal cross-sectional view of a furnace lining using the composite of the present invention, and Figure 4 is a diagram of a furnace lining using the composite of the present invention. A perspective view showing the cutout state of the lining sealer construction for a chemical plant, Fig. 5 is an explanatory diagram showing various uneven shapes of the ceramic sintered body, and Fig. 6 is an apparatus (mold) used for manufacturing the composite of the present invention. FIG. 1... Cast metal part, 2... Rod-shaped ceramic sintered body, 3... Tube-shaped ceramic sintered body. 4... Plate-shaped ceramic sintered body, 5...
···template. 6... Keren, 7... Spruce. Name of patent applicant: IBIDEN Co., Ltd. Representative: Jun Taga Figure 5 (a) (b) (c) (d) (e) Figure 6

Claims (1)

[Scope of Claims] 1. A ceramic-cast metal composite, characterized in that at least a portion of the casting is composed of a ceramic sintered body. 2. The composite body according to claim 1, wherein at least a portion of the cast material has an outer surface or an inner surface made of a ceramic sintered body surface. 3. The casting is a cast iron casting steel casting whose mother alloy is iron, copper, aluminum, zinc, magnesium, or tin;
A patent claim characterized in that it is any one or more of copper or copper alloy castings, aluminum or aluminum alloy castings, zinc or zinc alloy castings, magnesium or magnesium alloy castings, tin or tin alloy castings. The complex according to Scope 1 or 2. A start - I + 1 ≦ ko htsugu pregnant horse mackerel 1 humble discharge 巳l carbon, silicon nitride, aluminum nitride, boron nitride. 4. The composite according to claim 1, wherein the composite material is any one or more of titanium nitride, aluminum oxide, sialon, zirconia, ferrite, cordinilite, and graphite. 5. The shape of the ceramic sintered body may be a plate-like object, a flat object with at least a flat surface, a tubular object, a rod-like object, or various shapes having pores or uneven parts on at least a part of the back surface or side surface thereof. A composite according to any one of claims 1 to 4, characterized in that: 6 Ceramics in which the surface of the ceramic sintered body is exposed from the mold to the surface or inner surface of at least a portion of the casting, after sintering the ceramic and temporarily fixing the supply body to any part of the casting mold, and then pouring the molten metal through the sprue. 1. A method for producing a ceramic-cast metal composite, which comprises taking out a composite composed of a sintered body and a cast metal, and subjecting the composite to post-treatment if necessary. 7. The manufacturing method according to claim 6, characterized in that the ceramic is temporarily fixed to the mold via a V-type screw.