JPH05200526A - Production of wear resistant composite material - Google Patents

Abstract

PURPOSE:To produce the wear resistant composite material having a combination of both advantages of the high toughness of an alloy system and the high hardness of ceramics. CONSTITUTION:A casting mold 1 consisting of a surface layer 2 formed by kneading an inorg. binder with coarse ceramic particles of about 1 to 3mm and molding the mixture and a back layer 3 formed by kneading the inorg. binder with ordinary fine ceramic particles and molding the mixture on the rear surface of this surface layer 2 is formed. This casting mold 1 is preheated to a high temp. and a molten metal is poured therein, by which a casting 6 having a wear resistant layer 5 combined with the ceramic particles on the surface is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wear resistant composite material such as a blast wear resistant and a slide wear resistant part.

[0002]

2. Description of the Related Art Blast wear and sliding wear parts are conventionally made of high chrome cast iron or other high hardness alloy or alumina,
High hardness ceramic parts such as silicon nitride have been used.
Further, only the surface of the metal is hardened by a method such as nitriding or carbonization. Alternatively, a surface treatment method has been adopted in which a high hardness material such as ceramics is attached by thermal spraying.

[0003]

However, these conventional members cannot provide sufficient hardness in the alloy system, and in the ceramic system, molding is difficult even if the hardness is sufficient, and complicated parts are required. However, there was a problem that it was not practical because it could not be made. With respect to blast wear resistance, ceramics, due to their inferior toughness, may cause slight wear when the collision particles are large and the mass is high, and may be more severe than the alloy system.

The present invention is directed to the production of a wear-resistant composite material which combines the advantages of the high toughness of the alloy system, the ease of formability and the high hardness of ceramics with respect to the disadvantages of the conventional wear-resistant composite materials. The purpose is to propose a method.

[0005]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. The present invention is based on coarse ceramic particles of about 1 to 3 mm and inorganic particles. A mold comprising a surface layer 2 which is formed by kneading a binder to form a wear resistant composite layer and a back layer 3 which is formed by kneading an inorganic binder with ordinary fine ceramic particles on the back surface of the surface layer 2. 1 is formed, the mold 1 is preheated to a high temperature, and a molten metal is poured into the mold 1 to produce a cast product 6 having a layer 5 on the surface of which composite particles of ceramic particles are formed by the thickness of the surface layer. Is characterized by.

[0006]

According to the present invention, the surface layer of the wear-resistant portion of the cast product is made into a composite with wear-resistant and high-hardness ceramics by the above-mentioned means, and the main body has the conventional metal properties (high toughness, working property). In addition, according to this method, any complicated shape can be manufactured.

In addition, since the composite part manufactured by this method has a shape in which a metal having high toughness is filled with hard ceramics, damage to the ceramics due to wear of the ceramics is unlikely to occur, especially with respect to blast wear. It can be said that it is a composite wear resistant part with extremely excellent wear resistance. Further, according to the present method, the high hardness ceramics to be composited can be composited of all materials including alumina, silicon nitride, silicon carbide, boron carbide, etc. or cemented carbide materials. This combines these ceramics and the like to form a mold. This is because the inorganic binder of colloidal silica or ethyl silicate has a sufficient adhesive force to all the binders, and is due to the manufacturing method of the present method in which this composite portion is formed by impregnation of the molten metal.

Further, as a binder for forming a mold,
By selecting an inorganic binder such as colloidal silica or ethyl silicate, this mold is about 1500 °
It can withstand high temperatures up to C without deformation. This makes it possible to supply the molten metal to the mold that has been kept at a sufficiently high temperature, and it is possible to stably impregnate the molten metal into the coarse particles on the surface of the mold and the voids between the particles, making it stable and sound. It became possible to manufacture cast products with various wear-resistant composite surface layers.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The present invention is, as shown in FIG. 1, a wear resistant composite in which the surface of a mold 1 is required to have wear resistance of a cast member. The surface layer 2 is formed by kneading the inorganic binder into coarse ceramic particles having a thickness of about 1 to 3 mm, and the back surface of the surface layer 2 is kneaded with inorganic binder into ordinary fine ceramic particles. And the molten metal is poured into this mold, the molten metal penetrates between the sand grains on the surface of the mold, and as shown in FIG. 2, a cast part 6 having a wear resistant layer 5 in which ceramic particles 4 are compounded is produced on the surface.

The inorganic binder is colloidal silica,
An inorganic binder capable of withstanding high-temperature firing of ethyl silicate and coarse particles are kneaded, and a surface layer is formed by molding a wooden mold for the thickness of the abrasion-resistant composite layer required.
This thickness is about 3 to 10 mm, and molding may be performed by the thickness of the composite portion to be molded. However, when the thickness is 10 mm or more, the molten metal is not sufficiently impregnated, so that it is preferably 10 mm or less in order to stably obtain a sound composite part.

Then, 5 to 20% of colloidal silica is mixed and kneaded with usual foundry sand such as zircon sand, and kneaded, and a mold is formed as a buff-up layer on the above-mentioned surface layer. After air-drying, it is removed from the wooden mold and baked at 1000 ° C to form a strong mold. The firing temperature is preferably 900 ° C. or higher from the viewpoint of strength development of the inorganic binder and colloidal silica, and sufficient strength is expressed at 1000 ° C., and need not be higher than that.

The mold produced in this manner is used as an upper mold, a lower mold,
If necessary, assemble a mold having a space for pouring molten metal by combining cores. This mold is fired again at 1000 ° C. and preheated. The preheating temperature needs to be a temperature at which the molten metal is sufficiently impregnated, but 1500 ° C from the deformation of the mold.
The following is desirable.

The mold preheated in this way was taken out of the firing furnace, and the molten metal of SUS310 was immediately cooled to 1600 °.
Cast in C. The material to be cast can be selected from high-chromium cast iron, heat-resistant steel, stainless steel, etc. depending on the intended use of the part, and any material that can be cast can be used. After casting, it is naturally cooled, the mold is disassembled, and the product is taken out. Except for the wear resistant part, it is the same as a normal cast product, so that it is possible to cut the riser, machine it, and so on.

As a result of a sandblasting wear test conducted on a cast product having a wear resistant composite layer on its surface, the wear resistance was three times higher than that of the uncomposited SUS310 material.

[0015]

As described above, according to the present invention, 1 to 3 m
A back surface formed by kneading an inorganic binder with coarse ceramic particles of about m to form a wear-resistant composite layer by a required thickness and a back surface of the surface layer by kneading an inorganic binder with ordinary fine ceramic particles. By forming a mold consisting of layers and preheating the mold to a high temperature, and pouring a molten metal into the mold, a cast product having a layer on the surface of which a composite of ceramic particles corresponding to the thickness of the surface layer was produced. Therefore, it is possible to stably manufacture a wear-resistant cast product in which ceramic particles are compounded on the surface, and the wear-resistant layer in which ceramics and metal are compounded has wear resistance and toughness, and It has higher wear resistance than parts made of only metal.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold according to an embodiment of the present invention.

FIG. 2 is a sectional view of a casting according to an embodiment of the present invention.

[Explanation of symbols]

 1 mold 2 surface layer 3 back layer 4 ceramic particles 5 wear-resistant layer 6 cast product

Claims (1)

[Claims] 1. A surface layer formed by kneading a coarse ceramic particle having a size of about 1 to 3 mm with an inorganic binder to a required thickness of a wear-resistant composite layer and an ordinary fine ceramic particle on the back surface of the surface layer. To form a mold comprising a back layer formed by kneading, and preheating the mold to a high temperature, and pouring a molten metal into the mold, so that the surface is coated with ceramic particles in an amount corresponding to the thickness of the surface layer. A method for producing an abrasion resistant composite material, which comprises producing a cast product having an abrasion layer.