JPS5874574A - Plasticity working tool for copper and copper alloy - 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 The present invention relates to a plastic working tool used for drawing, wire drawing, wire rolling, extrusion, or die casting of alloys mainly composed of copper and steel.

Conventionally, cemented carbide and die steel high speed steel have been used as plastic working tools for copper and copper alloys.

However, the manufacturing conditions for mass-produced products, such as wire drawing rolls, have become stricter year by year due to higher precision and economic demands, and as a result, plastic working tools have also become more demanding, such as heat resistance, abrasion resistance, and thermal shock resistance. In order to meet these demands, new materials are being developed day and night in the fields of cemented carbide, die steel, etc., but no material with the above performance has yet been found. It has not been.

As mentioned above, metal plastic working tool materials are generally made of tool steel or cemented carbide, and even when looking at the movement toward new plastic working tool materials, there have only been slight changes.

On the other hand, ceramics have recently attracted attention as a material for plastic working tools, but their thermal shock resistance, impact resistance,
Because properties such as pigeonness are inferior to those of the above-mentioned materials,
Among plastic working tools, it is only gradually beginning to be used in the field of guide rolls, etc., which have low stress, and the idea of using it for rolling rolls has hardly been considered.

The present inventors have arrived at the present invention as a result of studying the possibility of using the material as a T-11 machining tool material over the wood.

That is, the present invention is a new plastic working tool made of a silicon nitride ceramic, in particular, a sintered body having 5% or less of pores and obtained by a force-pressure sintering method.

This brings about a revolutionary change that breaks the conventional concept of various plastic working tools.

Even though silicon nitride is a ceramic material, it has the same weaknesses as a ceramic, but on the other hand, it is superior to the metal materials in terms of wear resistance, especially at -temperature. In terms of wear resistance, 10 to 1
It reaches a value of 00 times. Therefore, among plastic working tools, it is particularly effective in the field of hot rolling rolls and the like that are used at high temperatures.

The general concept for conventional jigs and tools is that they reach the end of their service life after a short period of use, so processes and equipment have been designed accordingly.

However, the plastic working tools of this invention have a lifespan of 10 to 100 times longer than conventional tools, and these jigs and tools have come to be considered part of the equipment.
For example, it becomes possible to think of adding it to regular maintenance items for the equipment itself, and as a result, not only will the operating rate of the equipment be improved, but also the amount of stock generated during the process will be reduced, and the large number of jigs and tools on hand will be reduced. No treatment is required9, and its effects are very large.

These plastic working tools differ depending on the metal to be plastic worked, but for example, when plastic working copper or copper alloys, tools made of conventional materials are used to A reaction occurs between the material and the processed material, a welding phenomenon occurs, and the surface layer repeats the phenomenon of welding and separation, which increases the roughness or wear of the surface layer, and eventually reaches the end of its life.

In addition, particularly during hot working, cemented carbide and die steel high speed steel are subject to repeated welding and separation, which causes cracks to occur due to a peeling phenomenon called spalling and fatigue phenomena, which causes a shortened service life.

In view of the Queen's point, the present inventors conducted studies to solve the drawbacks of conventional plastic working tools for steel and copper alloys, and as a result they arrived at this invention.

That is, the present invention provides a raw material composition for plastic working tools for steel and copper alloys, including 8t3N407596 or more □ Al, 0.
, MgO,Mg5N* e Bed, OaO,F
ed, A et al.

1 to 20% by weight of one or more of Mo, O, or A41N, Y2O2, ZrO,, Tie,, H
fO,,8i(3,CeO□.

It is characterized by being made of a Si, N4 sintered body containing 1 to 20% by weight of 1111 or two or more of TiN, W (3, No, C) and 6% or less of pores.

Hereinafter, the present invention will be described in detail. First, it is important to construct the tool with a material that exhibits a bathing phenomenon as small as one lens.

However, ceramics have low weldability to metals.

Among them, the most common alumina-based ceramic has low strength and cannot withstand use in plastic processing where it is subjected to high stress and impact due to reliability problems.

So I tried testing with each persimmon ceramic tool.
: 2'8 + 3 N4 It was discovered that t-based ceramic exhibits better performance as a plastic working tool for copper and copper alloys than conventionally used cemented carbide and die steel. be.

Regarding Si3N, which is used as the main material in this invention, two methods are known: a reaction sintering method of nitriding, and a powder metallurgy method of mixing Si3N with additives. It is being However, the former method has more than 10% pores, making it unsuitable for the purpose of the present invention.

It is also known that the latter production method uses additives, which greatly affect properties and quality.

However, basically, high strength and impact resistance are required, and for this purpose it is necessary to use 75% by weight or more of Si3N4.

Next, additives used for 8i, N4 weighing more than 75% are Al2O,, MgO, Mg, N2, Ba
d, CeO2゜F'eO, AI, We, Mo2C
film or two or more of 'tl~20% by weight or AIM, YIO3e ZrO,t'I'io,
.

1ife, , 8iC,0eO2,'I'iN, W
1 to 20 of 1 m or 2 or more of e, Mo, 0
Weight percent is preferred.

If it is less than 1% by weight, sufficient strength cannot be obtained;
If it exceeds 0% by weight, the rounding becomes brittle.

A sintered body having such a composition shows little deterioration in strength, hardness, etc. even under usage conditions of 900'0 or less, and therefore is suitable for hot extrusion die 7 for buttons used under such conditions.
, rolling rolls, guide rolls, and other cold plastic working tools. At the same time, its life as a cutting tool for copper and copper alloys is significantly extended.

Such a sintered body is produced by thoroughly pulverizing and mixing the mixed powder weighed to the above-mentioned σ force using means 1 such as a ball mill.
~4t/lI! Molding was carried out at a pressure of 2.0 N. Mr.
A sintered body having 5% or less of pores can be obtained by sintering at 1,600 to 1,900° C. in an inert atmosphere, an ammonia atmosphere, or a reduced pressure atmosphere.

In such a tool, if too many holes remain, the strength and reliability will decrease, so it is preferable to have as high a density as possible. From this point of view, it is appropriate for the number of pores to be 5% or less, but in areas where the manufacturing and usage conditions of the tool are not so severe, pores of less than 10q6 do not have much of an effect.

Additionally, metals such as R, Fe, Co, and Ni as additives can be effective if used in small amounts.

Regarding 8 i 3N4, either the β type or β type can be used without any difference in effectiveness.

Hereinafter, the present invention will be explained in detail by way of examples.

Examples 1 to 10 8i3N was mixed with various sintering aids in the proportions shown in Table 1 and mixed in a ball mill, then l t/am
Press molding was carried out at a pressure of 1.5" and then sintered at 1700 to 1850"C for 4 hours under a nitrogen pressure of 1 voltage to produce a 10th stage hot rolling row A/10 type for finishing copper wire.

The results of each rolling temperature, the amount of rolling required to reach the end of life, and the causes of life are as shown in Table 1.

Table 1 In conventional rolling rolls made of cemented carbide, die steel, high speed steel, etc., the rolling amount of copper wire is 500 to 700.
However, it was confirmed that the rolling roll of the present invention having a composition shown in Table 1 above had a life span 2 to 5 times longer.

It has been found that these rolling rolls have a particularly long life under conditions of 900°C or lower, and that their lifespan rapidly decreases when the temperature exceeds 900°C, making it impossible to obtain the desired wear resistance.

Example 11 Commercially available 8i3N480% by weight, Al2O, 15% by weight,
A guide roller for copper wire drawing was prepared in the same rectangular shape as in Example 1 by mixing 05% by weight of Mg. The sintering temperature at this time is 1
The temperature was 700°C.

We conducted a comparison test on the service life of the guide roller of this example with commercially available guide loaves made of cemented carbide and alumina ceramic, and the results shown in Table 2 were obtained, indicating that the guide loaf of this example was It has been proven to be very good.

In addition, the wire rod has a speed coefficient temperature of 500° at 5 m/sec.
It was C.

Claims (2)

[Claims] (1) 8i, 75% by weight or more of N4 contains A4,03I MgO・M g 3 N 2 e B eO@G a
Oe F eO* Al e We *AruiiijMo
A plastic processing tool for copper and copper alloys made of a sintered body of 8i, N, containing 1 to 20% of 2001 species or two or more species and having 5% or less of pores. (2) 8i, 75% by weight or more of N4 #N, Y
,03°ZrO2,Tie, ,HfO,,8i0.
CeO, TiN, We. 1 to 20% by weight of one or more of Mo20
A plastic working tool for copper and copper alloys according to claim 1, characterized in that it contains a plastic working tool for copper and copper alloys.