JPH0742482B2 - Light molding method - Google Patents

Description

The present invention relates to a method for producing a sintered compact comprising metal or ceramic powder or a mixed powder of metal and ceramic by an optical molding technique using a photocurable resin, In particular, the present invention relates to a method for three-dimensionally molding a metal or ceramic powder or a mixture thereof without using a mold such as a mold, and a method for producing a functionally graded material or the like in which the component mixture ratio is changed.

[Conventional technology]

The conventional photo-molding technology using a photo-curable resin is mainly a method of irradiating a composition containing a photo-curable resin as a main component with light to produce a molded article having a predetermined shape. Due to its insufficient mechanical strength and thermal resistance, it was exclusively used for making models (models, etc.)
Application (Chemical Society of Japan), 3rd revised edition, published March 15, 1980, pages 799 to 806 (Maruzen)].

In addition, the conventional molding technology for metal powder, ceramic powder, or mixed powder thereof is mainly based on a mold, and therefore, expensive molds are manufactured or molds are changed when changing product types. However, complicated work such as the above was also required, and it was not suitable for high-mix low-volume production [Precision Handbook, 11th edition, issued October 15, 1986, 17th
Pages 45 to 1750 (Corona).

Furthermore, for example, in a method for producing a so-called functionally graded material in which the component mixture ratio is changed stepwise, conventionally, plasma spraying or the like [Precision Work Handbook, 11th edition, issued October 15, 1986, p. 1344] From 1345 to 1345 (Corona Corp.)], the area of the functionally gradient material obtained is small because it was prepared by changing the composition of the material to be sprayed or by implanting other atoms on the metal surface by the ion plating method or the like. Moreover, there is a problem that it takes a long time to manufacture.

[Problems to be Solved by the Invention]

As described above, the conventional method for producing a molded body made of metal powder or ceramic powder has a problem that it is not suitable for high-mix low-volume production because it is a mold-based molding technology. In the production, there are problems that the area of the obtained material is small and the production requires a long time.

An object of the present invention is to solve the above problems in the prior art, and the first object of the present invention is to:
A method for producing a sintered compact made of a metal powder, a ceramic powder, or a mixed powder thereof, which can be easily produced by a photoforming technique using a photocurable resin without using a mold which is a mainstream of conventional techniques. To provide an optical molding method suitable for high-mix low-volume production that can
The purpose of the method is to form a functionally graded material with a different component mixture ratio on a predetermined substrate by a photo-molding technique using a photo-curable resin, which is continuously laminated to produce a large area with a large area. An object of the present invention is to provide a method for efficiently manufacturing a functionally graded material.

[Means for Solving the Problems]

To achieve the first object of the present invention, the photoforming method,
By carrying out the following manufacturing steps, it is possible to obtain a sintered compact made of a desired metal powder, ceramic powder, or a mixed powder thereof.

(1) For example, a metal powder made of iron, copper, aluminum and an alloy based on it, a ceramic powder such as silicon carbide, silicon nitride, alumina, etc., alone or as a mixed powder thereof, or if necessary, a resin or paraffin. ,
A step of preparing a powder-mixed photocurable resin liquid by mixing it in a liquid photocurable resin together with a binder material containing a low melting point metal powder, cobalt powder, and the like.

(2) The above powder-mixed photo-curable resin liquid is applied onto, for example, a substrate, and X-ray, laser, and so on so as to have an irradiation surface of a set shape
The step of irradiating an electromagnetic wave such as an ultraviolet ray or a visible ray to cure the photocurable resin is repeated at least once to form a three-dimensional molded body in which a powder mixed resin layer is laminated, or the above powder mixed photocurable The surface of the moving stage installed in the resin liquid is positioned below the surface of the resin liquid by a predetermined depth so that the resin liquid having a predetermined thickness is formed on the surface of the moving liquid, and then the predetermined shape is obtained. The resin solution is cured by irradiating electromagnetic waves so that it has an irradiation surface of
Then, the moving stage is lowered stepwise into the resin liquid to form the resin liquid having a predetermined thickness on the surface of the stage, and the electromagnetic wave is irradiated to successively laminate and cure the photocurable resin to form a three-dimensional molded body. Forming step.

(3) Metal powder by heating in a high temperature atmosphere to burn and remove the resin component in the three-dimensional molded body made of the above-mentioned cured powder-mixed photo-curable resin, and to combine the powders contained therein. Alternatively, a step of forming a three-dimensionally-shaped sintered compact made of ceramic powder or a mixed powder thereof.

In order to achieve the second object of the present invention, which is a method of forming a functionally graded material with a changed composition ratio, the following manufacturing steps are performed to obtain a desired metal, ceramic powder, or a mixture thereof. A functionally graded material made of powder can be obtained.

(1) Metal powder, ceramic powder alone or a mixed powder thereof, or together with a binder material, if necessary,
A step of preparing a powder-mixed photocurable resin liquid by mixing it with a liquid photocurable resin.

(2) A step of applying the powder-mixed photocurable resin liquid on a substrate to a predetermined thickness and irradiating an electromagnetic wave from above to cure the photocurable resin.

(3) After the steps (1) and (2) are repeated while changing the compounding ratio of the metal and the ceramic powder stepwise, the resin compounded body having a laminated structure is formed by changing the compounding ratio of the components a predetermined number of times. , Heating in a high-temperature atmosphere to burn and remove the resin component in the molded body, bond the powders contained therein, and change the mixing ratio distribution of metal and ceramic in the thickness direction. Process of forming a functionally graded sintered compact of shape.

As the photo-curable resin, α, such as cinnamic acid,
A photodimerization type photosensitive resin made of a β-unsaturated carbonyl compound, or a photopolymerization type photosensitive resin made of various vinyl monomers is preferably used.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in more detail with reference to the drawings.

(Example 1) A three-dimensional molded body shown in Figs. 1 (a), (b), and (c) was produced using the apparatus having the configuration shown in Fig. 2. First,
A metal powder, a ceramic powder, or a mixed powder thereof is added to a liquid photocurable resin to prepare a powder-mixed photocurable resin liquid 9, or a binder substance is added to the resin liquid to powder-mix photocurable resin. A resin solution 9 is prepared and filled in the tank 8.

A stage 7 having a structure capable of gradually descending and moving is disposed in the tank 8, and the stage 7 is submerged by a predetermined depth from the liquid surface of the powder-mixed photocurable resin liquid 9 so that it is placed on the upper surface of the stage 7. , A powder-mixed photocurable resin liquid layer having a predetermined thickness to be cured [first
[Fig. (A)] is controlled so that the electromagnetic wave is radiated from above so that it has an X- and Y-axis plane projection shape of the three-dimensional object to be molded, that is, a circular slice-shaped irradiation surface. After the resin liquid layer is cured by the above, the stage 7 is gradually lowered in the Z-axis direction of the three-dimensional object to be molded, and the resin liquid layer is cured on top of the first exposure-cured layer. The thickness of the resin is controlled, and the operation of irradiating an electromagnetic wave so as to have the irradiation surface having the above-mentioned predetermined shape to cure the resin liquid layer is repeated a predetermined number of times, thereby attempting to form the resin 3.
It is possible to form a powder-mixed resin cured molding of a three-dimensional object [Fig. 1 (b)].

Next, the molded body that has been cured by irradiation with the electromagnetic wave is shaped into a molded body if necessary, and then placed in a high-temperature atmosphere firing furnace to burn off the resin component and burn the powder. By tying, a sintered molded product made of metal, ceramic or metal ceramic can be produced [Fig. 1 (c)].

As described above, the optical molding method for a metal and / or ceramic sintered body of the present invention can directly form a molded body of any desired shape without using a mold, Since high-mix low-volume production can be carried out efficiently, the design and processing time can be significantly shortened, and the product cost can be further reduced.

Example 2 As shown in FIG. 4, a resin coating unit for uniformly coating a carrier substrate on a moving stage with a metal powder or a ceramic powder mixed with a liquid photocurable resin or a mixed powder thereof, A resin curing unit that irradiates electromagnetic waves to the coated powder mixed resin layer so as to have an irradiation surface in a predetermined shape to cure the photocurable resin, and the surface of the cured powder mixed resin layer that is pressed by a roll or the like. Was used and a manufacturing module composed of a resin pressurizing unit for increasing the powder bonding degree by pressurization was used, and the powder component composition ratio was changed for each module as shown in FIG. 5 (a), for example. A tandem combination type in which manufacturing modules are continuously arranged and the powder-mixed resin layers are sequentially and sequentially laminated while moving the stage, or FIG. 5 (b).
As shown in Fig. 2, the repeating type manufacturing in which the powder mixture resin layer is laminated while the carrier substrate on the moving stage is reciprocally moved by changing the component mixture ratio in the resin coating unit in one manufacturing module for each layer The system makes it possible to mold a functionally graded material having a predetermined shape with a changed composition ratio. In the repetitive manufacturing system, a switching control mechanism for a plurality of powder mixed resin liquid supply systems having different component mixing ratios from the coating unit is required.

Using the above manufacturing system, a functionally graded material having the structure shown in FIG. 3 was manufactured by the following procedure.

From the normal line of the substrate 6 made of a metal thin plate or a ceramic thin plate placed on the moving stage, a liquid photo-curable resin mixed with a predetermined amount of metal / ceramic powder (adding a binder substance as necessary) is applied, After coating a certain amount of the powdered resin solution on the substrate [FIG. 3 (a)], it was exposed to an electromagnetic wave source and cured [FIG. 3 (b)].

Next, the powder-mixed resin liquid in which the mixed composition of the metal / ceramic powder is changed is laminated in the same manner as described above,
This was repeated a required number of times to form a plate-shaped raw material composed of a laminated body of powder mixed resin layers inclined to the required composition distribution. Next, this was charged into a high-temperature atmosphere firing furnace, the resin component was burned and removed, and the powder was sintered to obtain a functionally graded material with a desired shape in which the component mixture ratio was changed. .

In this example, the substrate 6 was used as the surface material of the functionally graded material, and the powder-mixed resin layer having a different component mixture ratio was laminated thereon. However, the substrate 6 was merely used as a carrier, and the above-mentioned powder mixture was used. It is also possible to obtain a functionally gradient material having a predetermined shape by a method of separating the substrate 6 at a stage after the resin layers are laminated and cured.

As described above, by using the photoforming method of the present invention,
It is possible to extremely efficiently obtain a functionally graded material having a predetermined shape in which the material component mixing ratio is changed between the front surface and the back surface of the material. It should be noted that in the repeatable manufacturing system, the device configuration is relatively simple, and it is effective for high-mix low-volume production, and in the tandem coupled manufacturing system, the functionally graded material of relatively low variety is mass-produced. Suitable for

〔The invention's effect〕

As described in detail above, in the case of producing a sintered compact made of a metal powder, a ceramic powder or a mixed powder thereof or a functionally graded material in which the component mixture ratio is changed by using the photoforming method of the present invention, the following will be shown. It has an excellent effect.

(1) Since the desired product shape can be formed directly from the CAD / CAM data, it is possible to efficiently carry out small-lot production of a wide variety of products.

(2) Since the required structure can be molded directly from the metal powder or ceramic powder material, the design and processing time can be shortened.

(3) The use of expensive and complicated molds and the like becomes unnecessary, and the processing cost of products with small production quantities can be greatly reduced.

(4) If a linear light emitting light source or a surface emitting light source is used in the optical molding method, the molding processing time can be further shortened and the product cost can be reduced.

[Brief description of drawings]

FIGS. 1 (a), (b), and (c) are schematic views showing the structure of the molded body produced in Example 1 of the present invention, and FIG. 2 is the production of the molded body produced in Example 1 of the present invention. 3 is a schematic diagram showing an outline of the apparatus used in FIG. 3, FIGS. 3 (a) and 3 (b) are schematic diagrams showing the constitution of the functionally graded material produced in Example 2 of the present invention, and FIG. 4 is an example of the present invention. 2 is an explanatory view showing a production module used for producing the functionally graded material produced in FIG. 2, and FIGS. 5 (a) and 5 (b) are configurations of the tandem coupling type and repetitive type production systems used in Example 2 of the present invention. FIG. 1 ... Metal particles, 2 ... Ceramic particles, 3 ... Binder material, 4 ... Photocurable resin, 5 ... Metal / ceramic particles, 6 ... Substrate, 7 ... Stage, 8 ... Tank, 9 ... Powder mixed light Curable resin liquid

Claims (1)

[Claims] 1. A single powder of metal or ceramic or a mixed powder of metal and ceramic is mixed into a liquid photocurable resin to prepare a powder mixed photocurable resin liquid, or a powder mixed resin liquid described above. Further, a step of adding a binder substance to form a powder-mixed photocurable resin liquid, applying the powder-mixed resin liquid on a substrate to a predetermined thickness, and irradiating electromagnetic waves to the applied powder-mixed resin layer to apply light. The step of curing the curable resin is referred to as a basic step, and the basic step is repeated a predetermined number of times while changing the compounding ratio of the metal and the ceramic in the powder-mixed photocurable resin liquid for each step, thereby forming a metal. And a ceramic component mixture ratio is changed for each coating layer to form a resin molded body of a predetermined shape consisting of a laminate of powder mixed resin layer, the resin molded body is heated in a high temperature atmosphere While baked removed, light shaping method characterized by forming a functional gradient material having a desired shape by sintering a powder containing.