JPS61176462A - Manufacture of composite ceramic casting - Google Patents

Abstract

PURPOSE:To improve the wear resistance of a casting by disposing a thin-walled metallic material made of the same or similar material as the casting on the outside of a hollow ceramic molding in tight contact therewith then pouring an insert-casting metal to the outside thereof thereby uniting said material and the metal. CONSTITUTION:The thin-walled metallic material 2 made of the same base alloy as the insert-casting metal 3 is disposed on the outside of the hollow ceramic molding 1 formed of ceramics such as silicon carbide in tight contact therewith. The combined material of the molding 1 and the material 2 is then disposed in a casting mold 4 and the metal 3 is poured into the mold to unite the combined materials 1, 2. Since the metal 3 of a high temp. does not contact directly with the molding 2, the cracking of the molding 2 is prevented. The wear resistance of the insert-casting is thus improved.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is applicable to parts that are hollow castings and require excellent wear resistance, corrosion resistance, and heat insulation properties, such as concrete pumps that require wear resistance. car gate housing material,
This article relates to a method for manufacturing cast ceramic composite castings used for diesel engine liners, chemical parts that require corrosion resistance, diesel engine exhaust pipes that require improved heat insulation, etc.0 (prior technology) For example, low-manganese cast steel has traditionally been used for the gate housing of concrete pump cars, which is a type of hollow casting, but the concrete mortar that passes through the gate housing wears it out in a short time, and the current situation is that it is replaced with a new part. It is.

As a countermeasure to this problem, high hardness cast iron, hardened overlay materials, and chrome plating materials are used, but this has not yet solved the wear problem.

Furthermore, a method of casting a ceramic molded body with molten metal in order to improve wear resistance, corrosion resistance, and heat insulation properties is already well known. However, with this method, cracks are often generated in the ceramic due to thermal shock during pouring of the molten metal and compressive stress when the molten metal solidifies and shrinks, making it difficult to put into practical use.

(Problems to be Solved by the Invention) The present invention seeks to provide metal parts and ceramic castings that can eliminate the drawbacks of the above-mentioned conventional methods.

(Another means to solve the problem) That is, in contrast to the conventional method in which molten metal is poured into the outside of a ceramic molded body prepared in advance, the present invention prepares a hollow ceramic molded body in advance and pours the molten metal into the outside of the ceramic molded body. After arranging a thin metal material of the same or similar material as the metal material that is in close contact with the material for the casting material, pour the metal material for the casting material on the outside of the thin material material, and weld the thin material material and the metal material for the casting material together. This is a method of bonding ceramics and integrating metal parts and ceramic molded bodies by casting. One of the features of the present invention is that because the partition walls are made of thin materials, the high temperature molten metal in the casting does not come into direct contact with the ceramics, thereby preventing cracks in the ceramics due to thermal shock.

Hereinafter, the method of the present invention will be explained in detail with reference to the accompanying drawings. Figures 1.2 and 3.4 are diagrams for explaining one embodiment of the method of the present invention.

In Figures 1 and 2, a single hollow ceramic molded body is made of alumina (AJzOs) and silicon nitride (Sl).

N4) and silicon carbide (S1a). 2
is a thin metal material manufactured so as to be in close contact with the outside of the hollow ceramic molded body 1, and is manufactured from the same base alloy as the casting metal 3 shown in FIGS. 3 and 4.

In other words, if the cast metal 3 is iron-based, the thin-walled material is also iron-based.
If it is a copper alloy, use a copper alloy, and if it is an aluminum alloy, use an aluminum alloy. The reason for this is that if the alloys are not of the same type, the fusion between the thin metal material 2 and the cast metal 3 will be incomplete.

When the cast metal 3 is iron-based, the thin metal material 2 is made of carbon steel, which is easily available and has excellent workability and cost. For the same reason, steel is used for copper alloys, and aluminum is used for aluminum alloys. .

Figures 3 and 4 show the product after being cast, with the combination of ceramic and thin metal material shown in Figures 1 and 2 placed in a mold 4 and cast metal 3 poured into it. It is.

In the present invention, the thickness K of the thin metal material 2 is limited,
If the thickness is too small, the thin metal material 2 will melt, and the hollow ceramic molded body 1 will be damaged by compressive stress when the cast metal 3 solidifies and shrinks. Further, if the thin metal material 2 is thick, the welding with the cast metal 3 will be poor. Examples of the present invention are shown in Table 1, and 11h1 and 2.3 have a wall thickness of 1.5 to 6 pieces, which is desirable as a thin metal material, and the casting condition is good. However, in -4 and Fl&L5, the thickness of the thin metal material was as thin as cL5 to 1 cL, so it melted and cracks occurred in the ceramics. -6 is a case where there is no thin metal material, and the ceramic was damaged by compressive stress during solidification and shrinkage.

-7 and N8 have thin metal material thickness of 8m and 91m.
Because it was as thick as 1II, the fusion between the thin metal material and the cast metal was poor. In the tests shown in Table 1, alumina and silicon nitride were used for the ceramics, and low manganese cast steel was used for the cast metal.

Ceramic casting materials were prototyped in the manner described above, and rotated and abraded for 15 hours in a concrete mortar having the composition shown in Table 2 to reduce the amount of abrasion and compare the abrasion resistance with conventional materials.

The conventional material used was low manganese cast steel for gate housings, whose wear resistance has been a problem in actual machines.

The wear test results are shown in Table 3, and the ceramic cast material was approximately 11 times more excellent in wear resistance than the conventionally used low manganese cast steel product.

Therefore, if the present invention material is used in parts that require wear resistance, such as concrete pump car gate housing materials and diesel engine liners, it will have significantly better wear resistance than conventional products, so it will be easier to prevent wear due to wear than conventional products. The degree of training required for replacement can be significantly reduced. As a result, equipment maintenance and inspection can be omitted for a long period of time, resulting in a significant cost reduction. Furthermore, since ceramic has excellent corrosion resistance and heat insulation properties, the material of the present invention can also be used for parts that require corrosion resistance and heat insulation properties.

Table 1 *1: JIS 50Mn3 Table 2 Table 3

[Brief explanation of drawings]

1 to 4 are diagrams for explaining the procedure of the method of the present invention.

Claims (1)

[Claims] In a method for manufacturing a ceramic composite casting in which a hollow ceramic molded body is cast into the hollow inner surface of a casting having a hollow part, a thin metal material made of the same material or similar material as the casting is closely placed on the outside of the hollow ceramic molded body. After that, a casting metal that will become a metal part is poured on the outside of the thin metal material, and the hollow ceramic molded body and the metal part are integrated as a casting. How to make castings.