Improving oxidation resistance of base metal powders

Literature. review Compaction

substrate

Metal powder compaction by differential speed rolling

making

S.Shima et al.

(Kyoto University, Kyoto, Japan.) J. Mater. Proc. Techn., Vol 111, No J-3, 2001, 113-117. Compaction technology speed

of metal

may superior to conventional

deposition

with

ring

a reciprocating

shape

It is shown that when the atom-

izer disc is located on the substrate axis or dis-

by rolling

placed in a direction

differential

plane.

Cu

powder

for

deposit growth is proposed.

powder

Electrolytic

in

model

A

deposit growth is symmetrical

is discussed, particularly

rolling.

preforms.

spray

substrate

was

perpendicular

It was possible

to the tilt

to make

a tapered

deposit.

rolled between rolls running at different speeds with roll speed ratios of 1.0 to 1.33 and controlled

powder feed rates.

rolling

load increases

feed volume:strip

Numerical simulation of die compaction with consideration of cracking

It was found that

as the ratio of powder

speed increased. The density

of the strip was 15%

higher

for differential

speed rolling than with conventional

O.Coube, rnsr. fiiT H.Riedel. (Fraunhofer WerkstofJinechanik, Freiburg, Germany.) Powder Met&, Vol43, No 2, 2OC0, 123-131.

rolling at

the same rolling load.

Die compaction the intention

Densification of mixed metal powders at high temperature

Powder Production

Densification

Economics of steel powder production by rotating electrode processes

of tool

steel

powder

mixed

using McMeeking

tials in deduction of constitutive element

calculations

creep poten-

for high-quality, identify

low cost powders is empha-

of technical

cost drivers

cost

models,

which

and aid in minimising

costs is discussed in terms of a caSe study, the production

of steel powders by rotating

elec-

trode processes. It is shown that there are possibilities for cost reductions.

agreement

coating with a mono-layer cementation kinetic

method.

differences

of noble metal by a

Thermodynamic

between

powders are considered.

and raw

Applications

are sug-

gested.

38

and

coated

MPR February

2002

on Fe powder.

Examples

are

of calculation

of

and that cracking

can be

Y.Thomaset al. (National Research Council, Bouche&e, Canada.) PowderMetall., Vo143, No2, ZOOO,139-142.

M.Sagawa er al. (Intermeraffics Co. Ltd., Kyoto, J ajxzn.) Mat&&/Design, VoI 21, no4, 2000, 243-249.

with Fe powder was investigated

Effect of temperature

Development

of rubber isostatic

pressing is

reviewed. It is reported that a new filling techair tapping

and grid separation,

shaping a wide range of metallic,

It is reported that the oxidation resistance of

are

formulated. Some parameters were determined

Rubber isostatic pressing for magnets and other materials

had

rubber isostatic pressing i useful technique

fine base metal powders had been increased by

in strength

Effect of temperature of lubricants during powder compaction

been developed and it is shown that this makes

C.A.Randali et al. (Israel Inst. of Technology, Haifa, Israel.) Japan. J. Applied Physic, Parr I, Vol39, No 10, 2000,6004-6007.

Drucker-Prager

for changes

with experiment.

nique,

improving oxidation resistance of base metal powders

model. Equations

strength and cohesion in the

modelled.

Advantages of PM are outlined and the need sised. Use

Cohesive

are considered

density distribution

models. Finite

showed fair

slope

given to show the accuracy

tigated by hot pressing and HIP. The process was modelled

formation unloading

experimentally

with varying amounts of Cu powder was inves-

D.A.Chiango et al. (Lucenr Technologies Inc. North AT&~, Mass, USA.) Int. J. PowdprMet&, Vol 36, No 4, ZOOO, 49-56.

crack

during powder transfer, compaction, and ejection.

J.H.Cho, K.T.Kim. (Pohang University of Science nnd Technology, Pohang, Korea.) Inr. J. Mech. Sciences, Vol 43, No4, 2001, 921-933.

of powder is modelled with

of describing

magnetic

ceramic

for and

materials.

Y.Y.Zhao. (University

of Liverpool, Liverpool, UK.) Vo143,No2, 2000, 117-122.

It is suggested that centrifugal tion (CSD)

using an instrumented

applied and transmitted ficient

is evaluated.

study revealed differences between

start and finish

was influenced

spray deposi-

using a tilted rotating

cylindrical

0026-0657/01/O-see

admixed

at X,65

and

die to measure

pressures. A slide coef-

This

is related

ratio and die wall coefficient

to stress

of friction.

The

in slide coefficient of compaction

by the amount of lubricant

the die wall. Stick-slip

Modelling of deposit growth on tilted rotating cylindrical substrate in spray deposition P&Me&l.,

llGC,

on lubricants

phenomena

and at

could arise

with low shear resistance.

Fluidised fill shoe for uniform die filling G.Gassbarre et al. (MATSYS Inc., USA.) Key Engineering Mater., Voll89-f 91, 2001, 288-294.. It is reported

that a fluidised fill shoe had

been developed

to increase powder flow and

front matter 0

2001

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