JPH03243787A - Production of metallic mold - 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 [Field of Industrial Application] The present invention relates to a method for manufacturing a mold having a concave molding surface.

[Prior art and its problems]

For example, Ti is applied to the molding surface of a synthetic resin injection mold.
When a hardened layer such as a ceramic film such as C, TiN, or T1CN or a dispersion plating layer in which these ceramics are dispersed is formed by PVD (physical vapor deposition) treatment such as ion blasting or dispersion plating treatment, these hardened layers are extremely Since the hardness is high and the surface is smooth, the frictional force and mold release force are reduced, reducing the damage rate of molded products during mold release.
Cycle time can also be shortened. In addition, the occurrence of deposits released from the melt in the mold is reduced, and there is no need to remove deposits, reducing downtime.

Furthermore, since the melt flow within the mold becomes longer, pressure loss, uneven temperature distribution, uneven wall thickness, etc. are alleviated, reducing molding defects, and corrosion resistance against hot gas is also greatly improved. .

Even when a hardened layer is formed on the press mold, cold welding and adhesive wear are reduced, which slows down surface shedding after microcracks occur, and processing is only possible after the hardened layer is formed. There are many cases where this has happened.

By the way, in PvD processing such as the ion blating method, a sufficient magnetic field is not formed in the deep grooves of the processed product, the inner surface of the hole, or the bottom surface of the hole, so it is difficult for ions to reach these parts, making it difficult to secure the required film thickness. There are problems in that it is difficult to adhere and the adhesion is not sufficient. Furthermore, in dispersion plating treatment, especially electrolytic plating treatment, it is difficult to uniformly disperse ceramics in deep grooves, inner surfaces of holes, or bottom surfaces of holes in the treated product. Therefore, when forming a hardened layer such as a dispersed plating layer on the molding surface of a mold (mother mold) with a concave molding surface, it is not possible to sufficiently coat deep structures or the inner surfaces of holes, so that the above-mentioned advantages cannot be fully obtained. For this reason, the mold is made into a split mold to eliminate deep grooves and holes, or vapor deposition is performed using CVD (chemical vapor deposition) processing, but if the mold is made into a split mold, the cost of the mold increases. Furthermore, CVD treatment requires heating the treated product to a high temperature and is only carried out in special cases.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a mold manufacturing method that can form a dispersed plating layer in which ceramic is uniformly dispersed even in deep grooves and hole inner surfaces of a mold with a concave molding surface. .

[Structure of the invention and its effects]

The mold manufacturing method of the present invention includes a step of forming a dispersed plating layer in which ceramic particles are dispersed on the surface of a convex master pattern, and a step of forming a backup shell on the dispersed plating layer by electroforming or the like. This method is characterized by including the steps of removing the master pattern from the dispersion plating layer to which the backup shell is in close contact, and incorporating the backup shell into the recess of the mold body.

That is, a master pattern for a mold with a concave molding surface is convex, and the portions corresponding to the deep grooves and holes of the mold become ridges and protrusions. For this reason, portions corresponding to deep grooves and holes can also be coated with a dispersion plating layer in which ceramic is uniformly dispersed through dispersion plating treatment using electrolytic plating. Then, after the backup shell is brought into close contact with this dispersion plating layer and the master pattern is removed, the backup shell is incorporated into the recess of the mold body, so the ceramic is evenly distributed even in the deep grooves and inner surfaces of the holes of the completed mold. coated with a dispersed plating layer.

〔Example〕

The present invention will be specifically described below based on embodiments shown in the drawings.

(1) Master pattern The master pattern l made of aluminum has a protrusion 11 corresponding to a deep hole in a mold having a concave molding surface and an annular protrusion corresponding to a groove in the mold, as shown in FIG. 1(A). 12 is formed and has a convex shape as a whole.

(2) Formation of a dispersion plating layer A dispersion plating layer 2 was formed on the surface of this master pattern 1 under the primary conditions as shown in FIG. 1 (CB).

Slurry nickel sulfamate 300 g / Q Nickel chloride 10 g / Q Boric acid 40 g / Q Ethylene glycol 100w1Q/ff1SiC (1
~3μm) 1gIQ Bath condition Slurry 100g/Q pH4.0 Temperature 50°C When treated under these conditions for 20 in., the film thickness was approx.
A μ-shaped dispersion plating layer 2 is formed, and a master pattern l
SiC is uniformly dispersed over the entire surface. Ceramics are not limited to SiC, but include TiC, TiN, WC, B4C, M
Various materials such as o, C, Cr5Cx can be used.

(3) Formation of backup shell When electroforming is performed for 240 hours under the following conditions, a backup shell 3 made of Ni with a film thickness of about 12 mm is formed as shown in Figure 1 (C), and the dispersion plating layer 2 closely adhere to.

Nickel sulfamate 300 g / Q Nickel hydrochloride 30 g / Q Boric acid 40 g / Q pH 4,0 Bath temperature 50°C Current density 8 A/d The method for forming the back-up shell 3 is not limited to electroforming, but also thermal spraying. , a pressing method such as HIP or SIP, or a hard resin.

(4) Removal and assembly of master pattern When immersed in water and sodium hydroxide (30g/Q),
The master pattern l made of aluminum is dissolved and removed, leaving a backup shell 3 to which the dispersion plating layer 2 is adhered. Then, the outer periphery is removed to the specified dimensions and shown in Figure 1C.
D), and the mold is assembled into the recess of the mold body 4, as shown in FIG. 1(E), to complete the mold. Note that the outer periphery of the backup shell 3 may be removed to a predetermined size, the master pattern 1 may be removed, and then the back-up shell 3 may be incorporated into the recessed portion of the mold body 4.

In this way, the dispersion plating layer 2 in which ceramic is uniformly dispersed is formed on the master pattern 1, so that the dispersion plating layer 2 in which ceramic is uniformly dispersed is also formed on the surfaces of the deep holes 51 and grooves 52 of the completed mold. is formed, making it possible to create a mold with an extremely hard molding surface.

〔Effect of the invention〕

As explained above, the mold manufacturing method of the present invention involves forming a dispersion plating layer in which ceramic is dispersed on the surface of a convex master pattern, bringing a backup shell into close contact with this dispersion plating layer, and removing the master pattern. After that, the backup shell is incorporated into the concave part of the mold body, so it is possible to form a dispersed plating layer in which the ceramic is evenly dispersed even in deep grooves and inside holes of the mold with a concave molding surface. .

[Brief explanation of drawings]

FIGS. 1(A) to 1(E) are process explanatory diagrams of an embodiment of the present invention.

Claims (1)

[Claims] A step of forming a dispersed plating layer in which ceramic particles are dispersed on the surface of a convex master pattern, a step of forming a backup shell on the dispersed plating layer by an electroforming method, etc. A method for manufacturing a mold, comprising the steps of: removing a master pattern from an adherent ceramic film; and incorporating a backup shell into a recess of a mold body.