JPS6082679A - Manufacture of metal mold by metal thermal spray and electroforming - Google Patents

Abstract

PURPOSE:To obtain a titled mold having excellent strength, precision, and durability by applying Ni electroforming to a model obtained by precision casting, and backing up a shell formed by spraying high-melting point metal. CONSTITUTION:A product model 1 is enclosed with a steel frame 2, and a low- melting point metal is sprayed to form a metallic layer 3. The melt of a ternary or quaternary alloy of Sn, Bi, In, etc. is poured into a reversed mold 5 obtained by releasing the model 1, cooled, and released to obtain the second precisely cast model 7. Ni electroforming 8 is applied on the surface of the second model 7, and a sprayed layer 9 is formed by bonding spraying a high-melting point metal such as stainless steel. The second model 7 is heated, melted, and released to obtain a hard metal shell 9. The shell 9 is fixed to a mold base 10, and the space on the rear side is backed up 11 with molten metal or a sprayed metal film, etc. A cooling water pipe 12 is embedded in the backup part 11. The metal mold is completed by finishing the recessed surface of the shell 9 with polishing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on room-temperature total refraction thermal spraying (Japanese Patent Publication No. 47-24859).
This relates to a method for manufacturing molds that not only have a high degree of M and are highly precise, but also have excellent durability. After making a model of the desired product and spraying metal on its surface, the model μ is released from the mold to form a shell μ made of a metal spray coating, and this is backed up to form a mold. Not only is it inferior in durability, but distortion occurs during the manufacturing process, and the precision of the shape and dimensions may cause problems. , -aL 7+ Tofu Kanoda Ayaya Tsumetatetsu An A Because it has to be repaired, metals with high hardness cannot be used, and therefore weak molds for manufacturing prototypes are required at best. However, the mold according to the present invention has almost the same strength and precision as an ordinary mold obtained by machining a metal block, and is excellent in durability.

Metal spraying technology, especially the above-mentioned Japanese patent (or U.S. Patent No. 8,
The method of making molds using the thermal spraying method disclosed in No. 901,441 (hereinafter referred to as room-temperature spraying) has the great advantage of being able to manufacture molds with complex shapes easily and in a short time, and is therefore inexpensive. mosquito! However, on the other hand, it has the drawbacks mentioned above.The reason for this is that there is a heat storage effect in the process of accumulating metal particles flying at extremely high speeds and forming a layer, and the particles fly one after another at extremely high speeds. Due to the collision, it is inevitable that this will cause a plastic effect and cause distortion as a whole, and it is also difficult to remove the resulting distortion, making it difficult to obtain the desired accuracy. Since the strength of the metal layer itself is not very high, it is necessary to reinforce it, but numerous tests and studies have shown that this is due to reasons such as the lack of developed means to increase the reinforcing effect without causing distortion etc. The result has been clarified.

The mold manufacturing method of the present invention is a method for manufacturing an innovative and excellent mold that eliminates these drawbacks and takes advantage of the excellent points.

To explain an example of the implementation of the present invention with reference to drawings, first, a model [+] of the target product is made from an easily processable material such as wood, gypsum, plastic, etc. (hereinafter referred to as the first model) (first model). figure),.

This first model is surrounded by a steel frame (2), and its surface and surroundings are made of metal that melts at low temperatures, such as zinc.
A metal layer (3) is formed by spraying aluminum or an alloy thereof at room temperature (FIG. 2). In this case, it is convenient to place the entire assembly on a base plate (4).

Next, by releasing the first model /l/(]) from the sprayed metal layer (3) thus formed, an inverted version (5) (sprayed shell/I/) of model (1) is obtained. After flattening the flow of the melt (7) of a low melting point alloy such as tin, binumanu, and indium into the inverted recessed space (6), a sprayed metal layer (3) is further formed. Low melting point metal part (7)
is released from the mold to obtain a precision cast body made of a low melting point metal that is exactly the same shape as the first model (this precision cast body is referred to as the second model (7)).
). This second model can be formed with extremely high precision because the low-melting point metal does not shrink and expands by a small amount of 0-6/100x after cooling.

Next, the surface of this second model /l/+71 is normally 1.
Nickel 7L' electroforming (8) with a thickness of 5 to 2.0x is applied to obtain an electroforming master. In addition, before performing this nickel ff1t casting, if necessary, the second model /L/(71
After polishing the surface, apply glossy nickel/I/electroforming to a thickness of 2 to 3 microns, and further polish the surface as necessary.
This may be subjected to electroforming of Nickel 7L'. Also, nickel electroforming is said to have a thickness of 1.5 to 2.0χ.

A high melting point metal such as nickel, nutless steel, etc., is sprayed onto the surface of the electroformed nickel (8) of the electroformed master thus obtained by bonding with a high adhesion force to form a sprayed layer (9) of the required thickness. A so-called overlay is formed (Fig. 4).

Furthermore, the entire structure shown in FIG. 4 is heated to a temperature (
200°C), for example in a furnace, to melt and remove the second model Jv(7) part, and then add a high melting point metal having nickel/l/'t14'', @j on the surface. A hard metal shell formed by thermal spraying (9) is obtained.

Then, the hard metal shell (9) is placed on a mold base (lO
) and then spray an appropriate metal such as zinc, a) v-minilam or an alloy thereof at room temperature into the space on the back side thereof, or
Back up (II) by pouring molten metal or, in some cases, pouring cement. Backup part (cooling paddy field pass 119 in one space) or book supply-F
6 and 1-1 The mold is completed.

Although the above explanation uses the mold base, it is preferable to use it for the convenience of handling intermediate products in the mold manufacturing process and for operational convenience.
Its use itself is not essential to the method of manufacturing the mold of the present invention. After the mold is completed, it is reattached to the mold base in the same way as a general mold.

The method for manufacturing a mold according to the present invention includes the above-mentioned process, that is, a series of steps, and the mold thus obtained is as follows:
It has many advantages, such as being highly accurate, making it possible to create precise shapes, being durable, being manufactured quickly, and therefore being inexpensive.To further explain this point, first, As mentioned above, it is not difficult to understand that the first model made of materials that are easy to process can be made easily and in a short time, no matter how precise or complex the shape. It is. Next, most of the processes of the present invention consist of a simple operation of backing up the production of the inverted mold by cold thermal spraying, and only a slight casting process of the second model is added to this, so sophisticated machinery is required. It does not require any equipment or skilled operations or techniques. It will be understood that for this reason, the mold can be completed in a short time and at low cost.

It is well known that melting q, j metal n da with a regular solvent can faithfully copy even the extremely detailed shape of the model surface, and the inverted type from the first model (5) is extremely faithful to the h11 of the first motel.
The second model obtained from this inverted mold is also a precision casting mold made of a special low-melting point alloy, so it is a faithful reproduction of the first model, and the final hard metal shell is also nickel). Since it is made by electroforming and cold-temperature spraying, it is a faithful copy of the second model, so the completed mold itself is extremely precise.

Now, looking at the overall distortion, which is considered to be the biggest drawback of the mold using the seed sprayed metal layer, the present invention solves this problem by using a hard metal shell (9) with nickel electrode. It is unique in that it is obtained by spraying a high melting point metal onto the casting surface.

It is said that when a melting point metal is thermally sprayed onto a nickel electroformed surface +81, the sprayed metal is sprayed in the form of fine particles at high speed, colliding with each other and mechanically bonding the fine particles. In the case of , the high melting point metal particles are melted into the particles on the metal coating surface and the two-dimensional nickel electroformed surface (8) due to the heat of the fine particles and the heat generated by collision, creating a welding bonding force.

This is a metal with poor thermal conductivity, such as iron (ferrous @ conductivity 0.1
40 CGS, 4'), etc.

Therefore, the sprayed metal shell obtained in this way, that is, the hard metal shell Lv, has a maximum strength of 20 Kq/md) and properly maintains its overall shape.
In addition, by backing up the original shell, we succeeded in obtaining a metal spraying mold that does not cause any distortion.The mold produced by the manufacturing method of the present invention is truly highly accurate and excellent, making it suitable for metal shaving. Comparable to a mold.

The second model (7) according to the present invention can be made from the melting point metal shell (5), and it is extremely easy to manufacture a plurality of molds of the same shape. Very advantageous in terms of time and economy. Also, as can be seen from the structure of the mold, shear Az (9j) is a nickel electrode with a high melting point metal layer welded to the nickel electrode surface 712,
The overall strength of the shell is extremely high, and
The inner surface is made of dynamic hardness metal, and the backup is firm, so the mold is completed with excellent durability. The metal thermal spraying means of the present invention is carried out by a conventional method, and involves a pretreatment process such as sandgellast, etc.
The use of a release agent etc. [11] is in accordance with conventional methods.

As described above, the present invention is a method for manufacturing molds with excellent Wj degree, precision, and +1IiJ durability in a short time and at low cost by repeating extremely simple steps, and is a method that can be used as a mold manufacturing method. It is temporary.

[Brief explanation of drawings]

Figure 1 is a front view of the first model, Figure 2 is an explanatory diagram showing the state of metal spraying on the surface of the first model, and Figure 8 is the melting of low melting point metal in the shell obtained by metal spraying in Figure 2. An explanatory diagram showing the state in which the liquid has been poured, Fig. 4 is an explanatory diagram showing the state in which hard metal has been sprayed on the surface of the second model, and Fig. 5 is an explanatory diagram showing the state in which the space on the back side of the hard metal shell is backed up. be. Symbol explanation m...First model, (2)...Steel frame, +3)...Sprayed metal layer, (4)...
... base plate, (5) ... inverted type, (6) ...
...concave space (5), (71...low melting point metal, (8)...nickel/l' electroforming, (9)...
...High melting point metal sprayed layer, (10) ...Mold bene, (1) ...Backup. Applicant Masu Hamamura Attorney Patent attorney Takashi Mizuguchi - Figure 1 Rin 2 figure

Claims (1)

[Claims] A model made of easily processable materials such as wood, plaster, plastic, etc. is placed in a steel frame, a low melting point metal (e.g. zinc or its alloy) is sprayed on the surface at room temperature, and then the model is released from the mold. An inverted mold made of a metal sprayed layer is made, and tin, bismuth, and indium S are placed inside the recessed part of the inverted mold.
A molten liquid of a low melting point metal consisting of a ternary to a duplex alloy is poured, and after cooling and solidifying, it is released from the inverted mold to make a second model.Next, the surface of this second model is coated with nickel/nickel of the required thickness. I
/Electroforming is performed, and then any high melting point metal (e.g. evanickel, stainless steel/I
/ etc.) After removing the obtained material to a temperature sufficient to melt the second model and surrounding the thus obtained hard metal shell with a mold base, the space on the back side of the shell μ is filled with suitable means, e.g. Metal spraying and electroforming are characterized by backing up with molten liquid or metal spray coating, etc., burying a cooling water pipe in this backup layer if necessary, and finally polishing the inner surface of the shell if necessary. Mold manufacturing method.