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Microstructure of gas and water atomized stainless steel powders
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
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