Rheological phenomena during capillary flow of hardmetal powder compacts

Rheological phenomena during capillary flow of hardmetal powder compacts

prepared by mechanical . compacted alloying by spark-plasma was added through alloy powder. Densification AlN or NbN pressed of N a w...

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prepared

by mechanical

.

compacted

alloying

by spark-plasma

was

added

through

alloy

powder.

Densification

AlN

or NbN

pressed of

N

a

was added

grain growth. from

the

and hot

sintering.

N

was rapid.

There

sup-

was no loss

mechanically

alloyed

specimens.

Compositions

bide phase were determined contain

Fe-9.85%N and this

were described. (Ti,W)C

determined

and

WC

in amounts

by the TIC content.

ity of the Tic-WC-Co WC-Co.

of the carand found to The ductil-

was higher

A high-temperature

used. Coating

of cutting

TiN, Ti(C,N)

and/or Al,O,

than

process

was

tools with TIC, increased

ser-

vice life.

Production of nano-particles by vapour phase condensation N.Kishkoparov

et al. (Fine Metal Powders

Co., Ekaterinburg, A study

Russia.)

of kinetics

and mechanisms

nano-powder

production

condensation

was described.

of Cu, Sn and Cu-Sn

of

by evaporation/ Production

alloy powders

was

reported.

University, Tallinn, Estonia.) Strength

and

reliability

steel/Tic-cermets were

produced

process.

by a diffusion

Effects

size range of 50nm

to lOOnm, had been

bustion

by vacuum synthesis.

vapour-phase

com-

The process was report-

Tallinn, Estonia.)

Production

It was

reported

energy

ball

extruded

milling

had been used to synthesise

TiC

for

that

elemental

Ti

parameters

micron Tic

high and

C.

and

Effects

of formation

were investigated electron

grained Tic-NiMo

of

of sub-

by X-ray dif-

microscopy.

was to optimise

production

The of fine

cermets.

of

inverse

Al alloys were discussed.

and applications

Needs

high

alloys

extrusion

and

extrusion steel

pressures

dies

to

conditions

as well as sintered investigation bilised reported

T.Gestrich et al. (Fraunhofer

the product.

Ceramics/Sintered.

inst.

hardmetals,

WC-Co

was

occurring

were

desorption of lubricants,

reduction

transformation

of liquids,

Effect of carbon content and

ties, magnetic

density on rolling contact fatigue

mass transport

of a steel

characterised

of

Technology, Aachen, Germany.) It was reported fatigue

tester

that

contact

had been developed.

This

was used to test Distaloy

HPl,

ious core

to 7.lgm/cm-“,

%C,

processed

hardened

Rolling

contact

108 cycles

and

mine the S/N curve. a maximum to

The

Hertzian

pressure

specimens

with

to

levels

to deter-

Endurance

reached

at a core carbon

0.4%.

ground.

tests extended

at five stress

highest was

surfaces

lubricants,

content

of

endurable

reached rolled

and

to

with to near

H13

steel

in

quality

of

which the speof

optimise

L.G.Bodrova, G.M.Kramar. (Temopil State Ivan Pul’uj Technical University, Ukraine.) Applications tools

of TiC

and for heat

were discussed

cermets,

as cutting

and wear

resistance,

with reference

to proper-

ties. A wide range of properties cermets

was investigated

the effects 1000°C.

with

of Tic regard

of VC, at temperatures

Substitution

of TIC

to

up to

for WC-Co

was reported.

T.Honek et al. (Tomas Bata University

A.V.Laptev,

in

Zlin, Zlin, Czech Republic.) Rheology

of powder

was discussed

injection

with reference

ery and proper

mould

sideration

hardmetals.

models

of were

tested limited

to

size distributions to

55~01%

con-

rheological and polymer

applicability

complex

of the powders.

with

Published

against

40~01%

gies,

Only due

moulding to machin-

filling

V.A.Falkovsky

hardmetals

outperform

of die life and surface

carbide-nickel by high energy hot

particle

of the effects of adding 4, 8,

cer-

Solid-state consolidation of tungsten

A titanium carbide hardmetal for steel cutting et al.( GUPVNIITS,

and a special

The last of these was

Rheological phenomena during capillary flow of hardmetal powder compacts

binders.

Moscow, Russia.)

sta-

processing.

found

June 2003

were

and allow predictions

behaviour

Hard materials

to WC-8%Co

of Co and These

by various techniques

data for a range of carbides

12 or lbwt%TiC

melting

were shown to yield data about thermal

as

of oxide impuri-

full density.

Investigations

identified

with var-

finish

fatigue

discussed.

phenomena.

cific mechanisms

a rolling

An

ZrOL

Properties of titanium carbide cermets of

Microstructure property relationships

P,Beiss. (Aachen University

to

H13 but not

Mater., Dresden,

Germany.) Processes

J.Petersen,

were noted. conditions

with Mg, Si,N,

terms

some severe

oxides or carbides.

of

Process during heat treatment of

for

withstand

can meet these

tungsten carbide-cobalt compacts

Sintering

ed to have low cost.

and struc-

aluminium alloys

met was described.

prepared

factors,

of the insert material

A.Caso et al. (Bettini SPA., Lecco, Italy.)

China.) powder, of high

bonding

of metallurgical

Cermet dies for hot extrusion of hard

fraction

shape and a particle

WCThese

mechanical activation of powder

object

It was reported that Bi,O,

dual

reviewed.

constituents ].Pirso et al. (Tallinn Technical University,

powders

purity, near spherical

of

were

ture of the steel were discussed.

ZSheng et al. (Guangzhou Research Inst. for Non-Ferrous Metals, Guangzhou,

0.2

H.Klaasen et al. (Tallinn Technical

properties

process

case

by diffusion bonding

Synthesis of titanium carbide by

from

Production of nanometre bismuth oxide

Compound carbide composites produced

was

pressing L.Fochas. (Inst. for Problems

of Materials Ukraine.)

Science of UAS, Kiev,

WC-26wt%Ni

hot-pressed samples

triple

to

1250°C.

hot-pressed

1100°C.

urn-sintered

and morpholo-

Densities

above

of

were

powder

high-energy 90%

unstable

flow

consolidated

on

feedstock

99%

attained

by

at 1150°C,

but

at 1150°C

samples

and

determined.

were

density. Properties

liquid-phase

Mechanical were

hot pressing

vacuum sintering

It was shown that the onset of

and

was made with vacu-

specimens. properties

at

were

at lOOO”C, 1050°C

Comparison

physical

with

depends

Some

characteristics,

Experiments

were high energy

950°C

described. temperature.

powders

ball milled and high-energy

attained

only

of the solid-state exceeded

those

sintered materials.

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