Mechanical properties of nitrided injection moulded iron

Mechanical properties of nitrided injection moulded iron

processes was discussed with regard to part quality, process economics and production of complex shaped parts. It was considered that the use of HIP, ...

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processes was discussed with regard to part quality, process economics and production of complex shaped parts. It was considered that the use of HIP, or otherwise, depended on control of ‘net’ or ‘near-net’ shape. The value of modelling and simulation of HIP was emphasized and the application of models was outlined. Some examples were given and discussed.

dropped to 25% in the pole direction and 14% in the pole boundary direction after debinding and sintering. Magnetic properties were described. POWDER METALLURGY IN ELECTROMAGNETIC APPLICATIONS

An investigation of dimensional changes during sintering of injection moulded parts was described. Use was made of timeindexed image acquisition and analysis which enabled estimation of part density as functions of time and temperature and in situ measurement of time to attain full

C.G. Oliver, H.G. Hutz. (Hoeganaes Riverton, New Jersey, USA).

density. Microscopic images of part surface were also obtained. It was attempted to correlate these with sintering environment.

Characterization of powders

The role technological

NEW TECHNIQUES

of magnetic

FOR

CHARACTERIZATION

OF SUB-MICRON

POWDERS FOR INJECTION

MOULDING

K.M. German et al. (Pennsylvania State University, Pennsylvania, USA). The application of injection moulding to production of near-net shaped complex parts was discussed with reference to the enhanced

sinterability

powders. of

Techniques

ultrafine

of

sub-micron

powders

were

outlined

and

discussed. MICROSTRUCTURE WATER ATOMIZED

OFGASAND STAINLESS STEEL

POWDERS J. Wang et al. (Chalmers Technology, Sweden.) The morphologies

University

of

and microstructures

of gas and water atomized 405, ferritic, and 1242 and 2390, martensitic, stainless steels were invest.igated size. The

as functions

particles

were

of PM, particularly recent advances, in the production materials was discussed.

Mechanical properties of high alloy steels MECHANICAL PROPERTIES STAINLESS STEELS H.1. Sanderow, Technologies

for characterization

Corp,

An

reference to distribution

(Concurrent

Corp, USA).

investigation

of

the

effects

of

composition, density and conditions on the mechanical

sintering properties

of 300 and 400 series stainless

steels was

described.

For a 300 series steel an increase

in density from 6.5-6.9 gm.cm-” gave a small increase in strength and large increases in ductility and impact strength. MIXED

POWDER

PERFORMANCE CONTACT

BLENDS

FOR BEST

to

be

N.C. Trilk et al. (Powdrex

the effects of size, and agglomeration,

shape, was

out. Models were constructed for size geometries to represent

industrial simulations

powders. were

experiments

to

parameters

and

The computer combined with

identify to

critical

construct

system sintering

maps. A GENERALIZED

SINTERING

FURNACE ATMOSPHERE ITS VERIFICATION

MODEL AND

T. Philips et al. (BOC Gases, Murray Hill, New Jersey, USA). Studies of sintering furnace atmosphere profiles and the effects of changes in the location of gas injection points, flow rates

USES

of particle

reported

carried various

IN WEAR ROLLING

AND GENERAL

OF

S.G. Dubois, R.M. German. (Pennsylvania State University, Pennsylvania, USA) Simulation of solid state sintering, with

OF

T. Prucher.

SIMULATION FOR SINTERING REAL POWDERS

Ltd, Tonbridge,

and

discussed

with

regard to the use of computational

composition

were

fluid

Kent, UK). The addition of tool steel powders to low

dynamics.

and the larger were equiaxed with surface dendritic patterns. 6 ferrite was found in

alloy steels, giving a low cost improvement

atmosphere

in mechanical

energy conservation

the smallest particles.

Powder blends for wear, rolling contact fatigue, a sinter hardening alloy and general

determine atmosphere profiles, which were verified experimentally. Applicability of the

mechanical

model was discussed.

either spheroidal particles

or in droplet

form. Small

were microcrystalline

or cellular

ANALYSIS OF GAS ATOMIZED COPPER

NOVEL

K.M. German.

(Pennsylvania

State University, Pennsylvania, USA). The development, alloys for electronics reported.

of metastable applications

lnvestigation

characteristics

of

Cu was the

of the alloys was described.

The objective was to develop powders with optimum properties for electronics applications.

reported.

applications

were

J.W. Simmons, J.S. Dunning. (US Bureau of Mines, Albany, Oregon, USA) The effects of N as an aloying element in stainless discussed

steels were described and with regard to solid solubility,

solution

hardening,

austenite

stabilization and corrosion resistance. High nitrogen stainless steels were

PRODUCTION OF POLE ANISOTROPIC STRONTIUM FERRITES BY INJECTION MOULDING IN MAGNETIC FIELD T.S. Cho et al. (Korea Inst. of Science and Seoul, Korea).

reported

to

have

significantly

higher

strength and similar ductility than 300 series stainless steels. Processing, structure and properties were described.

ModeMing of sin tering

It was reported that pole oriented Sr ferrite rings, for use in DC motors, had been

MONITORING

fabricated

SINTERING

ferrite

by MIM. 1 urn anisotropic

powders

were

mixed

with

Sr-

44~01%

OTHER

AND CONTROL

D.W. Yoel et al. (Centorr/Vacuum tries Inc, Nashau, New Hampshire,

42

MPR February

1996

OF

where mass and

equations

are used to

MECHANICAL PROPERTIES OF NITRIDED INJECTION MOULDED IRON J. Rawers, F. Croydon

(US Bureau of Mines,

USA) Effects of processing 316L

stainless

atmosphere in structure 0.15wtX

steel

injection in

a

moulded N

or

Ar

was investigated

for changes

and properties.

For N up to

no

structural

detected. Samples tensile properties

changes

were

processed in Ar had below those of cast

alloys but for those treated in N the properties were similar to cast materials. PRODUCTION

OF AUTOMOTIVE

ADJUSTMENT

PARTS USING

INJECTION I.

IN SITU TECHNIQUES

in the pole direction

This

was described

of furnace

MOULDING

SEAT

TECHNOLOGY

USING IniIAGING AND

binder, injection moulded in a magnetic field. The particle alignment was about 85X after moulding.

model

Metal injection moulding

HIGH STRENGTH STAINLESS STEELS THROUGH ALLOYING WITH NITROGEN

solid

Magnetic materials

Technology,

property

was

suggested.

ALLOYS

K.G. Iacocca,

properties,

A simplified

Haupt,

H. Hartmut

(Arburg

GmbH,

Lossburg, Germany). IndusUSA).

It was reported that MIM had been used to manufacture Fe-2!%Ni steel gears for use