Effect of sintering atmosphere on corrosion and mechanical properties of stainless steels

Effect of sintering atmosphere on corrosion and mechanical properties of stainless steels

Control of sintered properties of iron-phosphorus by adjustment of sintering conditions Injection moulding for production of copper alloys with tungs...

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Control of sintered properties of iron-phosphorus by adjustment of sintering conditions

Injection moulding for production of copper alloys with tungsten or molybdenum

compressibility

B.Hu. (Pyron Corporation, USA.)

EPetzofdt et al (Fraunhofer Inst., IFAh4, Germany.)

evaluated and discussed.

Structural

and electomagnetic

applications

The

improve compactability erties

small size of parts used in electronics

of Fe-P alloys were discussed with reference to

packaging was noted. Properties were discussed

properties.

and W-Cu and MO-Cu were shown to be suit-

It was noted that, due to a liquid

phase formed during sintering,

there may be

poor dimensional

control

for understanding

and control of sintering con-

ditions

to

dimensions.

attain

and there is a need

required

Sintering

properties

and

of pure Fe and Fe-P

alloys at conventional

temperature,

and at high temperature,

112OoC

tigated to determine

effects of sintering atmoson

Dimensional

time

uses in respect conductivity

expansion

mechanical

sintered

properties.

changes were sensitive to atmos-

phere, N:H ratio, but not to time, hardness and transverse rupture strength were not affected.

properties.

Effect of method of adding and distribution of copper on properties of steel etal. (Sundram Fasteners Ltd., In&.)

The strong influence

of Cu on dimensional

changes in PM Fe alloys was noted. of mixing

Cu into

Methods

the Fe, mixing,

mixing

with a binder to bond the powders and prealloying,

were considered and these were inves-

tigated

to determine

sintered

properties.

distribution,

Production

methods and by injection

distribution

of Cu and

Effectiveness

of the Cu

using a range of initial

ingredi-

ents was discussed.

Powder injection moulding

that

cast aerospace

one was under consideration. base IN718 moulding Machining

of an

part by a sintered The alloy was Ni

that would be made by injection with

a water-based

agar

binder.

costs would be markedly reduced.

The density, shape retention

and mechanical

properties of the sintered parts were shown to be superior to those of the cast parts.

(Pennsylvania

StateUniversity,

The effects of adding WC powder to M2 tool steel powder, on sintering, properties and structure, were investigated. moulded. materials

Comparison

Samples were injection was made

with and without

between

the added WC.

WC additions were shown to increase the sintering window and improve mechanical erties.

Variations

in %WC

were also studied.

www.metal-nowder.net

and particle

propsize

It was shown that the corrosion resistance of stainless

steel can be compromised

high sintering temperatures

Effects of process parameters on impact toughness of injection moulded parts

position

moulding

was

discussed

such as Fe or

variations

tion runs. Un-notched

within

with

Charpy specimens were

moulded samples and results were analysed for statistical variations and effects of process paraSuggestions

1Oppm to 2500ppm, 115O”C, 1230°C or

13 15”C, have on corrosion stainless

resistance

steel were investigated

tests on 5%NaCl

of 3 16L

by corrosion

solution.

produc-

used to evaluate inpact toughness of injection

meters.

that even out com-

The effects that levels of

and sintering temperature,

regard to properties and it was noted that there may be significant

differences.

the above contaminants,

J.W.Newkirk et al. (Uniwersity of Missouri-Rolla, USA.)

were made for improve-

ments in toughness and reproducibility.

Test methods Measurement of electrical conductivity in green-state powder compacts D.Apelian et al. (Worcester Polytechnic Inst., USA.) Measurement

Injection moulding of aluminium nitride

that an electrostatic

had been developed to determine

moulding

and

the product evaluated.

Feedstock

and process conditions

composition

were optimized. Effects

from the binder were investi-

and thermal conductivity

of green density was discussed.

It was reported

Qu Xuanhui. (Central South University of Technology, Changsha, China.)

on the AlN partidensity

were discussed.

tribution

in green compacts.

passed through voltages

are measured

predict

and compared

The

in density

A clear correlation

were used to throughout

and compact

density. The

Stainless steels Effect of sintering atmosphere on corrosion and mechanical properties of stainless steels

Investigation of sintering by noncontact electromagnetic acoustic transducers

P.K.Samal et al. (OMG Americas, USA.)

J.A.Foky, in H avoids

of Cr nitrides and gives better cor-

D.K.Rehbein. (Ames Laboratory, USA.)

It was reported that non-contact netic

the

was established

presence of lubricant was considered.

Sintering of stainless steel in H and dissociat-

with a

The results were

measurements

resistivity

is

surface

to various densities

lubricant.

variations

compacts.

Direct current

studies were carried out

on Fe powder, compacted with and without evaluated.

method

density dis-

the part and resultant

model. Experimental

between

precipitation

H.Zhang, R.M.Gennan. USA.)

P.K.Samal J.B.Tewell. (OMG Americas, USA.)

ferritic stainless steel. This can be alleviated by

ed NH3 were compared. Sintering

Addition of carbides on sintering of injection-moulded tool steel

identified,

Effects of contamination level and sintering temperature on corrosion of stainless steel

by particles of lower alloy content

costs.

cle surfaces. Effects of C on sintered

replacement

were

shaping and low production

gated. C reacted with Al,O,

K.Barton et al. (Honeywell PowderFlo Technologies, USA.)

density

austenitic

of C remaining

Injection moulding of an aerospace part

investment

by PM

moulding were com-

AlN was made by injection

It was reported

of and

and sintered

to

and hence green prop-

pared. It was shown that MIM offers near net

Injection

S.Ashok

and

129OoC, were inves-

phere

and

able for microelectronics thermal

due to the high alloy content

compared with lower alloy steels. Methods

acoustic

transducers

study sintering

electromag-

had been

in situ. Samples

used to

studied were

gives steels

high purity Al, Ag , Cu and Fe and were made

properties. Samples of 2

by uniaxial pressing. Changes in amplitude and

stainless steels were sintered at 1260°C in H, H-

velocity of acoustic waves were measured during

lO%N or cracked NH3 and cooled at three dif-

sintering.

ferent rates. H-lO%N

microstructures

rosion

resistance.

Cracked

with better mechanical

NH3

gave a good combination

of corrosion and mechanical

Evolution

properties.

The

changes and

were correlated

mechanical

changes in a series of echoes in the

samples provided data concerning

Evaluation of methods for improving green properties of stainless steels J.H.Reinshagen, R.P.Mason. (AMETEK Special Metal Products, USA.) Properties powders

in compaction

were

reviewed.

of stainless These

have

with

properties. the progress

of sintering and development of internal defects.

Defect definition - structural not visual W.Kitson et al. (Quasar International Inc., USA.)

steel

A

low

which

definition fails

in

MPR

of its

a defective application,

lulv/Aunust

part,

one

was given.

2002

87