JP3236385B2 - Mold for ceramic powder molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder molding die used for manufacturing a product by adding a binder to a powder of a material generally called ceramics and dry-molding the same.

[0002]

2. Description of the Related Art Conventionally, a molding die used when a binder is added to a powder of a material generally called ceramics such as an oxide-based / non-oxide-based ceramic material or a ferrite-based magnetic material and press-formed is used. As shown in FIG . Generally, this powder molding die is composed of a die 1, an upper punch 2 (in some cases, plural) and a lower punch 3 (in some cases, plural). The three surfaces (the surfaces that are in direct contact with the powder and the sliding surfaces of the dies and the punch) have extremely short life due to the abrasion caused by the powder, increase the cost of the die, and have to replace the die in a short time. As a result, productivity was significantly impaired. Further, as a material of the conventional mold, alloy tool steel (JIS G440) is used.
4), high speed tool steel (JIS G4403), carbide (V
10-V60 was used.

[0003]

As described above, conventional powder molding dies are appropriately selected from alloy tool steels to high-speed tool steels, and furthermore, to appropriately select materials for extending the life of the dies such as carbide. And gradually becoming more sophisticated. However, wear resistance, galling resistance, and seizure resistance (releasability) are still inadequate, and further improvements in wear resistance and releasability in particular are inevitable in order to extend the life. What is needed is the reality.

[0004] Therefore, conventionally, Japanese Utility Model Publication No. 4-6883,
JP-A-2-285064 and JP-B-3-178.
No. 91 discloses coating on a mold surface. For example, in Japanese Patent Application Laid-Open No.
The first layer in contact with the mold base material is coated with pure Ti to increase the adhesion, but pure Ti has a low hardness of Hv = 700-900, High hardness (Hv = 2000-240)
Coating the TiN layer of 0) is not practical because the effect is not so large.

In Japanese Patent Publication No. 3-17891, coating is performed in two layers. However, the first layer requires a nitriding furnace and takes about 20 hours, resulting in poor equipment cost and efficiency and cost reduction. Problematic and impractical. Furthermore, in Japanese Patent Application Laid-Open No. 4-6883, the first layer is made of TiC
Although TiC has a high hardness, its adhesion to the base material is inferior to that of TiN, and the problem of peeling of the coating still remains practically.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for forming a first layer of a base material using an alloy tool steel (JIS G4404) or a high-speed tool steel (JIS G4403) as a base material of a mold. TiN film with good adhesion and good wear resistance
By laminating the films, a long life mold having good adhesion and abrasion resistance was realized. TiCN is TiN and TiC
Was found to be a solid solution having a low chemical reactivity close to that of TiN and stable. Then, by further laminating the second layer as the third layer and coating the film with TiN, the releasability from the powder is improved, the effect is extremely large in practical use, and all of the above problems are solved. We were able to.

[0007] It is an essence of the invention, the ceramic powder was added to the binder in the press mold to carry out a dry, the mold base material low-alloy tool steel, high alloy da
Chair steel or high-speed steel, and the surface of the die
A first layer coating of N is formed and then laminated to the first layer to form a second layer coating of TiCN, and a second layer of TiCN is formed over the second layer.
Further, the third layer film of TiN is tempered with the tempering temperature of the mold base material.
A mold for molding ceramic powder , wherein a surface coating is formed at the following temperature .

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a ceramic powder molding die according to the present invention. As shown in FIG. 1, the ceramic powder molding die includes a die 1, an upper punch 2, and a lower punch 3.
The surface is severely worn by powder. Therefore, the coating layer 4 on the surface of the die 1 and the upper punch 2 and the lower punch 3
Need to be applied. Reference numeral 1 'denotes an inner die, and 5
Indicates powder.

Therefore, in order to prevent the coating 4 from peeling (deterioration) from the interface between the mold base material and the coating and from the inside of the coating (deterioration), in the present invention, as shown in FIG. A TiN film 7 having good adhesiveness is applied as a first layer and a second layer is laminated on the first layer to form a titanium carbide or titanium carbonitride film 8 which is TiC _X
When expressed as N _1-x , a TiC _x N _1-x film is applied as a second layer. At this time, the coating components are controlled so that 0 <x ≦ 1. In order to further improve the releasability from the powder, a ceramic powder molding mold having good wear resistance and releasability is developed by forming a coating of TiN9 as a third layer by laminating it on the second layer. I was able to.

[0010]

The material used as the base material in the present invention is a low alloy tool steel (SKS2, 3 etc.), a high alloy die steel (SKD11 or DC53) or a high speed steel (S
KH51), and it is important to form a surface film at a temperature equal to or lower than the tempering temperature of the mold base material. Because if the film is formed above the tempering temperature of the base material, the base material will soften,
This is because the dimensions may change and the mold may become unusable. In addition, these films are formed by chemical vapor deposition (CVD),
Coating technology such as physical vapor deposition (PVD) can be used, but physical vapor deposition (PVD) has a lower processing temperature and has less deformation, deformation, and softening of the base material and is used as a mold. If you are suitable. In particular, an ion plating method is preferable because of its high adhesion.

[0011]

EXAMPLES Table 1 shows the material of the base material and the life (durability) index as a test result as the operating conditions of the examples and comparative examples of the present invention. As shown in Table 1, the life of the mold was much longer in the present invention than in the conventional method.

[0012]

[Table 1]

[0013]

As described above, according to the present invention, the life of the mold can be greatly extended as compared with the conventional method, the cost of the mold can be reduced, the frequency of the mold replacement can be reduced, and the productivity can be reduced. Was significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a ceramic powder molding die according to the present invention,

FIG. 2 is a sectional view of a ceramic coating layer according to the present invention;

FIG. 3 is a cross-sectional view of a conventional powder molding die.

[Explanation of symbols]

 Reference Signs List 1 die 1 'inner die 2 upper punch 3 lower punch 4 coating layer 5 powder 6 base material 7 TiN film 8 titanium carbonitride film 9 TiN film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-231175 (JP, A) JP-A-2-159363 (JP, A) JP-A-3-122280 (JP, A) JP-A 61-231 170559 (JP, A) JP-A-53-82672 (JP, A) JP-A-49-66513 (JP, A) JP-A-4-164504 (JP, A) JP-A-2-159363 (JP, A) JP-A-5-214512 (JP, A) JP-A-5-285511 (JP, A) JP-A-5-320913 (JP, A) Japanese Utility Model Laid-Open No. 64-25103 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B28B 3/02 C23C 14/00-14/58

Claims (1)

(57) [Claims] 1. A ceramic powder is added with a binder.
In the dry press molding, the mold base material is
Low alloy tool steel, high alloy die steel or high speed steel,
Forming a first layer coating of TiN on the surface of the mold base material , and then laminating the first layer to form a second layer coating of TiCN , and further forming a third layer of TiN on the second layer; The coating
A mold for forming ceramic powder , wherein a surface coating is formed at a temperature equal to or lower than a tempering temperature of a mold base material .