JPS63195172A - Ceramic mold and punch for forming dry battery fuel - 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] This invention is applicable to the production of various dry batteries such as manganese dry batteries, alkaline dry batteries, and mercury batteries. The present invention relates to molds and punches used in encapsulation molding processes, etc., and particularly relates to ceramic molds and punches that exhibit excellent corrosion resistance and abrasion resistance against fuel.

[Conventional technology]

Conventionally, for example, molds and punches made of stellite or stainless steel have been used to form fuel pellets, and molds and punches made of stellite or stainless steel have been used to mold fuel into zinc cylinders, and %WC-based super-base hard alloy speed steel and stainless steel have been used to mold fuel into zinc cylinders. Currently, molds and punches are mainly used, and the materials used are selected depending on the purpose of use.

[Problem that the invention seeks to solve]

In this way, the materials that make up the molds and punches are not constant, and these molds and punches are corroded by the fuel, which contains highly corrosive components such as manganese dioxide and electrolyte. The problem is that it is easily damaged, is subject to significant wear, and reaches the end of its service life in a relatively short period of time.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors developed a metal that can be used for all fuel forming processes such as fuel pellet forming and encapsulation into zinc cylinders, and that also exhibits excellent corrosion resistance and wear resistance. As a result of research to develop molds and punches, we found that a composite metal oxynitride consisting of one or more of Mgs Ys and rare earth elements, and one or more of Si and AA as binder phase forming components = 2 ~20%, and further, if necessary, carbides and oxides of metals from groups 4a, 5a, and 6a of the periodic table, nitrides of metals from groups 4a and 5a, and solid solutions of two or more of these metals. (Hereinafter, these are collectively referred to as metal carbon, nitride, and oxides) 1 or more 20, 5 ~
40%.

, and the rest is silicon nitride as a hard phase forming component (
(hereinafter referred to as Si3N4) and Sialon (generally 81
and M oxynitride) and unavoidable impurities.
%) and a ceramic having a theoretical density ratio of 98% or more.

In addition, in molds and punches in which there are no pores of 2 μm or more on the molding surface and the surface roughness of the molding surface is 1.38 or more, the above ceramics can be used for any fuel molding. It has been found that corrosion resistance and abrasion resistance are ensured, and the above-mentioned molding surface properties ensure excellent moldability, and as a result, excellent molding performance can be exhibited over an extremely long period of time. It is.

This invention has been made based on the above findings, and the reason why the component composition and molding surface properties are limited as described above will be explained below.

A. Component composition (a) Composite metal oxynitride The ceramic of the present invention basically ensures excellent corrosion resistance and wear resistance by 5i5N4 and sialon as hard phase forming components, while on the other hand, it has excellent corrosion resistance and wear resistance as a binder phase forming component. The composite metal oxynitride ensures high density and high strength. Therefore, the content of composite metal oxynitride is 2
If the content is less than 20%, it will not be possible to secure the desired high strength and high density of theoretical density ratio: 98% or more, while if the content exceeds 20%, the wear resistance will decrease. Its content was determined to be 2 to 20%.

(b) Carbon, nitride, and oxides of metals These components have the effect of improving the strength of ceramics, so they are included as necessary, but if their content is less than 0.54, the desired strength cannot be achieved. No strength improvement effect was obtained,
On the other hand, if the content exceeds 40%, the strength will decrease significantly, so the content should be reduced to 0.5 to 40%.
It is determined that

B. Theoretical density ratio In order to ensure the desired excellent wear resistance and to prevent the presence of pores of 2 μm or more on the molded surface, the theoretical density ratio needs to be 98% or more. 98%
If the theoretical density ratio is less than that, the hardness of the ceramic will decrease to 1600 or less in terms of Vickers hardness, and pores of 0.2 μm or more will exist on the molded surface.

Furthermore, when attempting to manufacture ceramics with a high density, HRP (hot isostatic pressing) or hot pressing is effective.

C1 voids on the molding surface If there are large pores of 0.2 μm or more on the molding surface, 1
For example, when forming pellets, the pellets become scratched, and these scratches can cause cracks to occur when pressing the pellets, impairing formability. It was made such that there were no pores of 0.2 μm or more.

D. Surface roughness of molding surface If the molding surface is rougher than 1.3S, friction with fuel during press molding will increase.

When molding the fuel into the zinc cylinder, smooth installation becomes difficult and formability deteriorates, so the surface roughness was set to be smooth with a surface roughness of 1.38 or more.

〔Example〕

Next, the present invention will be specifically explained using examples.

Raw material powders include 5i5N4 powder, SiO2 powder, AIN powder, Al2O3 powder% MgO powder, and Y2O powder, all of which have an average particle size within the range of 0.5 to 3,/j m.
, powder, La2O3 powder, Ce2O3 powder, as well as carbide powders and oxide powders of metals of groups 4a, 5a, and 6a of the periodic table, and nitride powders of metals of groups 4a and 5a of the periodic table.

Furthermore, metal carbonitride powder, metal carbonate powder, metal oxynitride powder, and metal carbonitoxide powder, which are solid solutions of two or more of these types, are prepared.

These raw material powders were blended into the composition shown in Table 1, mixed for 72 hours in a ball mill under normal conditions, dried, and then pressed into a green compact at a pressure of 1 ton/cIn2. After molding, this green compact is
Normally sintered at 1,750°C in a nitrogen atmosphere of 1 atm for 2 hours, or sintered in a nitrogen atmosphere at 16
By hot pressing at a temperature of 50°C, the molds and punches 1 to 16 of the present invention having the component compositions shown in Table 1 were produced (the molds and punches 7 to 9 of the present invention were hot pressed). The other products were manufactured by ordinary sintering. For comparison purposes, conventional molds and punches 1 to 3 having the same compositions shown in Table 1 were prepared. Note that the mold has an outer diameter of 37 mm x inner diameter of 12 mm.
．． The punch had a ring shape with dimensions of 3MX height: 45 mm, and the punch had an outer diameter of 23.3 LI+.

Next, for the various molds and punches obtained as a result, the theoretical density ratio was measured, as well as the presence or absence of pores of 0 or 1 μm or more on the molding surface, and the surface roughness of the molding surface. Outer diameter for AA batteries: 12.
A fuel having dimensions of 3" x height of 219" was used for molding the pellets, and the number of shots until the amount of wear reached 50 μm, which is a guideline for the service life of this type of mold and punch, was measured.

These results are shown in Table 2.

〔Effect of the invention〕

From the results shown in the second test, the mold and punch 1 of the present invention
It is clear that all of the molds and punches 1 to 16 have a much better service life than the conventional molds and punches 1 to 3.

As mentioned above, the ceramic mold and punch of the present invention have excellent corrosion resistance and abrasion resistance, so when used for forming fuel for dry batteries, they exhibit excellent performance. This allows for long-term use.

Claims (2)

[Claims] (1) Contains 2 to 20% of a composite metal oxynitride of one or more of Mg, Y, and rare earth elements and one or more of Si and M as a bonding phase forming component, The remainder is composed of a composition (volume %) consisting of one or more of silicon nitride and sialon as hard phase forming components and unavoidable impurities, and a ceramic having a theoretical density ratio of 98% or more, and A ceramic mold and punch for forming a fuel for a dry battery, characterized in that there are no pores of 2 μm or more and the molding surface has a surface roughness of 1.3S or more. (2) Contains 2 to 20% of a composite metal oxynitride of one or more of Mg, Y, and rare earth elements and one or more of Si and M as a bonding phase forming component, Furthermore, carbides and oxides of metals from groups 4a, 5a, and 6a of the periodic table, nitrides of metals from groups 4a and 5a, and one or more solid solutions of two or more of these: 0.5 to 4
0%, with the remainder consisting of one or more of silicon nitride and sialon as hard phase forming components and unavoidable impurities (volume %), and a theoretical density ratio of 98% or more. 2μ on the molded surface
A ceramic mold and punch for forming a fuel for a dry battery, characterized in that there are no pores of m or more in size, and the molding surface has a surface roughness of 1.3S or more.