JPS589744A - Production of precision mold - Google Patents

Abstract

PURPOSE:To produce precision molds simply and easily by the use of inexpensive materials by mixing binders and a good electrical conductor material with zircon type powder treated in an electrolyte soln., coating the mixture on the surface of a pattern, and heating the same electrically to allow the coating to harden. CONSTITUTION:Zircon type sand or fine grain sand is used for the aggregate of refractory materials, and the sand is beforehand treated in an electrolyte soln. Inorg. and org. binders are used, for which a part or a number of kinds of water glass, bentonite, starch, CMC, hexametaphosphoric acid are used. As the good electrical conductor, 1 or 2 kinds of compds. among Ca, Na, K, Mg, Al, etc. are added in the form of an aq. soln. The refractory material 2 obtd. by mixing the above-mentioned materials is coated or packed on the surface of a wooden pattern 1 and is heated electrically via electrodes 3, 3, whereby the material is heated quickly and the hardened layer is formed. The pattern 1 is removed, and the precision mold is obtained.

Description

[Detailed Description of the Invention] The present invention mainly consists of zircon-based powder. - This relates to a precision mold that is molded and solidified in accordance with a model.

Conventionally, precision molds have been manufactured by adding ethyl silicate or the like to zircon powder, hydrolyzing it, and firing it. In the present invention, a caking agent and a good electrical conductor substance are added to and mixed with zircon-based powder that has been previously treated in an electrolyte solution, applied to the surface layer of a model, and dehydrated and solidified by applying electricity. The thickness of the mold layer can also be freely controlled by adjusting .

The firing process in conventional precision molds has the drawback of significantly increasing mold manufacturing costs.

Also, ethyl silicate as a binder is expensive.
It has the disadvantage that it can only be applied to high-quality cast products.

Solving these shortcomings and making a versatile precision mold simply and easily is not only a dream of the foundry people, but also has an extremely wide range of applications. The present invention provides a method for solving such problems.

That is, the present invention involves adding and mixing inorganic and organic binders and electrically conductive substances to zircon-based powder treated in an electrolyte solution, and coating or filling the surface of a model with the resulting refractory material. The present invention relates to a method for manufacturing a precision mold, characterized in that the material part is dehydrated and solidified by applying electricity to the material part, and a subsequent model is separated.

The aggregate of the refractory material used in the present invention may be commonly used zircon-based powder or fine-grained sand1, and the binder may be water glass, bentonite, starch, CMC, or hexametaphosphoric acid monomer. The aggregate is treated in advance in an electrolyte solution.

In addition, as electrically conductive substances, Ca%Na, Ki, Mg, A
Add one or two compounds such as J to an aqueous solution.

The above-mentioned mixed refractory material is optionally coated or filled on the surface layer of the model, and by energizing it, water is dehydrated in a short time to form a hardened layer.

As for the energization method, an electrode formed of a copper plate is attached to an arbitrary position, and electricity is applied at a voltage of 50 to 100V. The energization time is about several minutes to 10-odd minutes.

The position for attaching the electrodes needs to be selected depending on the shape of the model, but it suffices to be at a position where current can easily flow, and its complexity can be ignored.

Next, examples will be described.

An example of the combination of fire-resistant substances is as follows.

, zircon powder (treated in 10% NaCl solution) 100
1 part bentonite 5 parts starch 3 parts electrically conductive material 5 parts This refractory material (2) was applied and filled onto the surface of the wooden mold (1) in a water-like manner, and energized at 100 V for 5 minutes using electrode (3) K. A solid mold was obtained, which was removed from the wooden mold (1) to obtain a precision mold. This mold had sufficient accuracy as a precision mold.

As described above, the present invention makes it possible to manufacture precision molds using inexpensive materials that have been conventionally used, at low manufacturing costs, and with simple operations.

[Brief explanation of the drawing]

The figure is an explanatory diagram of the precision casting manufacturing method of the present invention. (1)--wooden mold, (2)-=refractory material (3)--electrode,

Claims (1)

[Claims] Add and mix inorganic and organic binders and electrically conductive substances to zircon-based powder treated in an electrolyte solution, apply or fill the resulting refractory material onto the surface of the model, and energize this refractory material part. A method for manufacturing a precision mold, characterized by dehydrating and solidifying it by K, and separating a post-model.