hard metal industry study

8/3/2019 Hard Metal Industry Study

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Hard Metal (WC-Co)

Market

Processes

Quantities

Manufacturers

Application

Dr. Wolf-W. Albrecht, retired Director of H.C. Starck, Germany

Dr. Fritsch Sondermaschinen GmbH, November 2008For internal use only


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Introduction:

The purpose of this report is to give a short description of markets,

processes, quantities, producers and application of hard metal (using

WC / Co) worldwide.

It shall render the application of the Dr. Fritsch pressure sintering

technology clearer and contribute to a more comprehensible discussion

on quality parameters of hard metals.

Technical and economic basis:

Tungsten is part of the family of refractory metals, i.e. of elements which

are very difficult to produce, due to their high melting temperature

(tungsten 3410C), among other things.

Its production therefore - unlike with most other metals - does not take

place by means of melting metallurgy but by chemical and/or thermal

treatment (see enclosure).

The central element of most hard metals is tungsten carbide (WC).

It is distinguished for its extreme melting temperature, and especially for

an excellent hardness.


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WC powder usually is mixed with Co metal powder (Atritor pulverizing)

and, by means of a sintering process (liquid-phase sintering), converted

into a solid object, which is denominated hard metal. Its hardness is

similar to diamond hardness. This is why its inventors, the Krupp

company, also called it Widia (like diamond).

Hard-metal producers worldwide do not only differ with respect to their

production method (mixing, pressing, sintering and coating) and to the

fields of application (processing of metals, composites, wood etc.) of

their products, but also with respect to the WC powder used:

- The standard in most companies is the purchase of WC, for

example from HC Starck, Wolfram Bergbau, or also from China.

Along with cobalt metal powder which is purchased as well, the

WC is then processed into hard metal, by mixing, pressing and

sintering it.

- Some of the very big hard-metal producers such as Mitsubishi

MMC, Sumitomo, Iscar / Taegu Tec and recently also Global

Tungsten & Powder Group (Metallwerk Plansee / OsramSylvania)

dispose of a tungsten chemistry of their own. For Chinese

producers, this seems to apply in general. These producers are in

a position to process ore (wolframite / scheelite) on plants of their

own and to produce WC for their hard-metal production.


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Thanks to its high scrap value, recycling of tungsten scrap has an

excellent rank and is therefore applied by many companies, viewing

the target of producing WC. These kinds of WC with a frequently

higher degree of impurities are added to the clean WC powders.

Further, very big hard-metal producers, such as Sandvik, Seco Tools

and Kennametal do not dispose of chemistry plants of their own, but

purchase large batches of tungsten compounds such as:

ammonium paratungstate (APT) and

tungsten oxide (which differs depending on its oxygen contents: blue

or yellow oxide; this is important, since different WC qualities result).

These compounds are then converted into WC on their own plants.

This WC is re-processed into hard metal.

Of course, these companies also purchase clean WC.


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Due to its parameters cleanness, grain size and grain distribution, WC

has a decisive influence on the quality of the hard metal produced

from it. The process of producing WC itself therefore in many cases

may not be neglected when assessing the quality of the hard metal.

For a better comprehension of the use of different tungsten products

and their processing into hard metal, which is somewhat confusing for

outsiders, production methods are represented in the following for:

- Ore processing into ammonium-paratungstate (APT)

- From APT to tungsten carbide (WC).

According to todays knowledge, the processes starting from ore

and/or alternatively from W-scrap, must be realized in order to

produce WC.

Tungsten Market:

According to latest figures (ITIA Meeting Xiamen, Sept. 2008) approx.

88 000 t of tungsten are consumed worldwide.


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Processing of ore into ammonium paratungstate APT


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From APT to WC


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This consumption is subdivided into

Western Europe: 23 000 t

USA 14 000 t

Japan 9 000 t

China 30 000 t

Russia 5 000 t

India 5 000 t

China is hence not only the biggest producer of tungsten worldwide,

but also the biggest consumer.

Referred to intermediate products which contain tungsten, the

following consumption results worldwide (figures referred to W-

content):

WC 63 000 t

FeW 8 000 t

W - metal products 7 000 t

W - compounds 5 000 t

W - various 4 500 t

These figures are explained in the following:

Hard metal made from WC finds its application in the following

sectors, for example:

General engineering, automotive engineering, energy and mining.


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FeW serves as alloy component for tool steel and for superalloys.

For W-metal products, tungsten powder is used for re-processing in

lighting industry, in the manufacture of contacts (with Cu, Ag), in the

military sector, for medical engineering and for aircraft construction.

Tungsten compounds are used for tungsten chemicals (e.g. W-acid),

for catalysts and for hydro-cracking.

Various tungsten products are used for surface coating for wear

protection and for surface hardening.

From the above figures, it is obvious that more than 70 % of tungsten

consumption worldwide refer to WC contained in hard metal.

WC consumption is subdivided as follows (W contents).

Western Europe 17 000 t

USA 10 000 t

Japan 5 000 t

China 16 000 t

Korea 3 000 t

Russia 4 000 t

India 4 000 t


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Western Europe and China are the biggest WC-producing regions

worldwide, with an increasing tendency, while production in the USA

is stagnating and the quantities produced in Japan are decreasing.

Hard-Metal Manufacture

The process is demonstrated in the following flowchart (manufacturing

process of hard metal):

Starting from powders such as WC and Co, and, if required, from

further carbides, hard metal is manufactured via wet pulverization

(Atritor), addition of binder and granulation for improving the flow

characteristics during pressing, as well as by pressing, removal of

binder, sintering and, sometimes, by repeated surface coating.

The sintering step would be the possible application for the Dr.

Fritsch pressure sintering technology.

Possible tasks from the new sintering technology might result in the

following sectors:

-process optimization (shorter sintering cycles)

- improvement of hard-metal quality (Co loss at high temperatures

and long sintering times might be an issue)

- reduction of the binder share (Co, Ni) up to processing without

binder

- use of alternative binders for hard metals.


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Production of Hard Metal


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Depending of the application of the hard metal - just to name some

examples:

machining of: metals, composites stone / mining / ceramics, oil-well

drilling, wood, for drills and cutters, for surface treatment, for hot-

rolling wear parts as well as projectiles for the military sector, -

different grain sizes of WC and Co are used.

Today, WC kinds from approx. 0.2 m up to 150 m are used, in order

to optimize hardness, strength and tenacity.

TaC or other carbides (TiC, TwiC, WTiTaC) are added only in few

cases, if, at high temperatures, a corrosion of the hard metal itself has

to be feared (example metal machining).

The following chart (ITIA publication) shows some examples of hard-

metal composition (WC / Co / Ti, Ta, NbC) with Co shares from 4 to

25 % as well as of the parameters measured at the sintered samples:

hardness, transverse rupture strength, fracture toughness, etc.

These parameters are decisive for the later use of the hard metal.


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This means that, when using the Dr. Fritsch pressure sintering

technology, on the one hand, a variety of production parameters from

the way from powder, its processing, up to its application will have to

be evaluated when assessing the quality of the sintered samples,

On the other hand, a series of parameters will have to be measured at

the sample itself. These parameters will then decide on whether the

new sintering technology offers advantages in the manufacturing

process of hard metal or with respect to the hard-metal properties.

It is recommendable to establish a corresponding test laboratory

(hard-metal laboratory) either in the Dr. Fritsch company or to contact

a corresponding commercial laboratory.

Manufacturers / Fields of Application

The following chart lists hard-metal manufacturers worldwide, as well

as their WC consumption (as W contents) and the fields of application

of the hard metals manufactured by them.

The chart does not claim to be complete; the quantities are to be

considered as approximate.

The deduction from worldwide consumption and/or consumption

according to continents and/or product sector, however, gives a

certain safety that the figures are not completely wrong.


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Manufacturer Country Application

1Henan ZhuZhou CC,Golden Egret, CBCarbide

China Metal processing / composites

2 Kennametal USA All applications

Sandvik Sweden All applications

4 CeratizitAustria /Luxemburg

Wood / stone processing

5Ghring, Gelit, Dr.Friedrich

Germany Metal / composite processing

6 TaeguTec / Iscar ROK / Israel Metal processing / composite

Seco Tools Sweden All applications

8 Newcomer, Vista USA Metal processing

Kyocera, Hitachi, SanAlloy

Japan Metal processing / composite

10 Betek Germany Stone processing / street working

Board Longyear USA Metal / stone processing

Saar Hartmetall Germany mining

Mitsubishi (MMC) Japan Metal processing / composite

Sumitomo Japan Metal processing / composite

Tungaloy (AMC) Japan Metal processing / composite

Iscar Israel Metal processing / composite

17 Hydrocarbide USA Metal processing

General Electric USA Metal processing

Dijet Japan Metal processing / composite


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Conclusion

Market, process, quantities, manufacturers and fields of application of

hard metal (WC/Co) have been summed up briefly, with the aim of

providing a basis for a discussion of the use of the Dr. Fritsch high-

pressure sintering technology. It is obvious that most of the listed

parameters have been treated only very briefly and consequently

require further explications.

This should, however, be the task of a future discussion.

hard metal industry study

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