Sintering behaviour of copper coated M2 high speed steel powders

boundaries were determined but were subject to contamination by 0. Solutions of TiBz in Ti-Fe liquids were investigated. Good wettability of TiBa by Ti-Fe liquid was reported. It was suggested that TiBa alloys could be made with a Ti-Fe matrix by liquid phase sintering. SINTERING COATED

BEHAVIOUR

OF COPPER

M2 HIGH SPEED

analysis. The parameters determined were volume fraction of solid, surface area of solid/pore interfaces and linear intercepts in solid and porous phases. A new model based on studies of Fe and Ni was proposed. COMPUTER SIMULATION OF MICROSTRUCTURES AND A MODEL FOR COMPACTED POWDERS

THE QUICRSET

I. Orgzall, B. Lorenz (University

ancourt,

STEEL

C. Quichaud

POWDERS

Potsdam, F. Molnar

et

al

(Technical

University,

Kosice, Slovak Republic). The vacuum sintering behaviour of M2 high speed steel powders coated with Cu was investigated.

The alloys contained

2 to

1OwtXCu. Effects of sintering temperature were determined. The Cu alloys were compared with M2 without Cu. Microstructures and properties were determined. The results were discussed in terms of sintering

was outlined. Factors considered included powders size and shape and size distribution, powder loading and binder characteristics. Particle contact coordination number distribution was calculated to evaluate flow of feedstock.

parameters.

of Potsdam,

Germany)

The compaction in two-dimensions

of powder was modelled by means of the

geometry of randomly shown that complete

placed discs. It was space tilling occurs

when there is a particle coordination number of 6. The results were discussed in

TRANSFORMATIONS

DURING

TRANSIENT

LIQUID

PHASE

SINTERING

OF IRON-TITANIUM

A. Cias, T. Pieczonka (Academy and Metallurgy, Krakow, Poland)

of Mining

The Quicksetm injection moulding for

J.M. Missiaen,

J.M. Chaix

application

Ti

powders

at temperatures

eutectic

temperatures

were

used

between

and

thicknesses be made.

0.5

(Inst.

National

sintered

TiBz was proposed.

Image

used to make a range of on TiBz-ZOvol%Fe with and

these

MODEL

ASSOCIATED

A. Ragulya

of

formed

the

K.J. Kurzylowski

(Warsaw

(Inst. for Problems

of Materials

specimens

sizes distribution way effect hardness

with differing

functions.

on mechanical

grain

An experimental

and theoretical study associated with thermally

sintering

activated

phase

described.

The

transformations integral

with

was

viscosity

regard

to

was phase

The

was found to obey the Hall-Petch

relationship grain size

except where there was a wide distribution when there was

reduced hardness. The possibility of using grain size engineering to improve mechanical

properties

temperature, heating rate differences between metals

SIZE EVOLUTION OF CARBIDES DURING SINTERING OF HIGH SPEED STEELS

was discussed.

J.M. Chaix et al (Inst. National

growth of M& carbides

speed steels was described. The steels differed significantly in carbide growth rates.

GRANULAR

MODELLING

INJECTION

MOULDING

(IJniversity

of Poitiers,

investigated

and by

between

cold isostatic

microstructure

was

quantitative

image

oxalic

acid

had

of

nitric

acid,

for

and exhaust

J.

Kihara

et

al

The

FOR

(University

development

dimensional

granular

the flow of feedstock

gas treatment.

Effects

of catalytic

moulded

of time, temperature

debound

layer

scanning

electron

of

of

two-

models in injection

and

was

of the Fe powder were discussed.

debinding

parts was described. and catalytic in detail. The

characterized

by

microscopy.

Oxidation

and sintering

behaviour

RHEOLOGICAL BEHAVIOUR OF BINDERS AND PLASTICIZERS USED IN METAL

INJECTION

MOULDING

T. Novae et al (Polytechnical Bucharest, The and

Bucharest,

rheological

plasticizers

moulding considered viscous viscosity rate

behaviour used

was investigated

modelled

University

in

of

binders

injection

experimentally

mathematically.

included

of

Romania).

activation

Factors energy

for

flow, index of flow, apparent and constants in the Arrhenius

equation.

The

main

conclusion

reported to be the determination maximum practicable solids content

was of the of WC-

Co feedstock. BURNOUT OF STEARIC ACID FROM INJECTION MOULDED COMPACTS

Tokyo,

Tokyo, Japan).

The relationship pressing

of the

in two sintered high

MICROSTRUCTURE et al

Polytechni-

que, Grenoble, France). An image analysis investigation

Metal injection moulding

Poitiers, France).

that

instead

PROPERTIES OF INJECTION MOULDED CATALYTICALLY DEBOUND IRON PARTS

and

MODELLING OF COLD ISOSTATIC PRESSING ACCORDING TO TYPE OF

M. Grosbas

to

This had a hvoproperties.

reported

used,

gas flow rate were described

Uni-

It was reported that PM had been used to prepare

et al (BASF AG, Ludwigsha-

An investigation

Kiev, Ukraine)

discussed

Warsaw, Poland),

DEBINDING

S. Ito et al (Citizen Watch Co Ltd, Saitama,

and new phases. The model was reported explain shrinkage interuptions during sintering.

versity of Technology,

could

Japan).

PROPERTIES

J.J. Bucki,

20 mm

WITH PHASE

composition, and viscosity

MATERIALS

to

OF SINTERING

EFFECT OF GRAIN SIZE DISTRIBUTION ON MECHANICAL OF POLYCRYSTALLINE

been

of injection

composition

modelhg

mm

IN CATALYTIC

M. Bliimacher

TRANSFORMATIONS

Science,

Microstructure

and

handling

It was deduced that liquid phase sintering is only possible over a small range.

cermet

fen, Germany).

the two

in the Fe-Ti system.

metal,

phase

analysis was measurements

PROCESS

sintered

to

a binderless was outlined

catalytic debinding of injection moulded parts. Oxalic acid had advantages in

PERCOLATION

spheroidal

process, system,

Polytechnique, Grenoblee, France). A model for the microstructure of liquid

mechanisms.

coarse

Bill-

OF LIQUID

PHASE SINTERED TITANIUM DIBORIDE-IRON HARDMETALS

described. The objective was to determine the diffusion and phase transformation and

Systems,

ceramic systems. It was reported that parts in the range 10 g to 1 kg and with

PROGRESS CHARACTERIZATION

about 3’%; porosity basis of the model.

sponge

Process

terms of relative density and pore space.

An experimental and model study of vacuum sintering of Fe-8’XTi alloys was

Fe

(Metal

France).

It was PHASE

PROCESS

three-

to describe moulding

H-H. Angermann, 0. van der Biest (Leuven University, Heverlee, Belgium). The kinetics of stearic acid removal from injection

moulded

compacts,

polypropylene/polyethylene investigated. Stearic acid much lower temperature

with

binder burns out

a

was at a

than the polymers,

MPR May 1995

49