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High density PM gears by enhanced solid state sintering
parameters and particle size distribution and microstructures were investigated for two Ni base alloys. Design of experiments concepts were used in an industrial setting. The most important parameters for particle
size distribution
gas pressure, alloy atomizer geometry.
were found to be composition
and
matrix, such as oxides or introduced by mechanical was investigated.
carbides, alloying,
A perspective powders
on metal
SOME
USES OF METAL
SURPRISING
A die lubrication PM parts production or die are heated,
FROM
OF ALUMINIUM
MECHANICALLY
ALLOY
ALLOYED
Unusual
and et al. (Polytechnic
University
of Madrid, Madrid, Spain. ) It was reported that a 2014 Al alloy powder had been prepared from elemental powders by mechanical alloying followed by extrusion at 500°C. with an extrusion ratio of 25:1, and heat treatment to optimize properties and structure. Powders and consolidated alloy were characterized and a high degree of homogeneity was reported. PRODUCTIVE
MECHANICAL
BY REPEATED J.
Kihara
et
POWDER al.
AL.LOYING
FORGING
(llniversity
of
Tokyo,
forging, with a load capacity of 500 tons was used to process Cu-Ag and a range of Al alloys.
Tungsten
heavy
DISTORTION SINTERED Upadhiya,
PHASE
(Pennsylvania
State University, USA) Shape control and dimensional
stability
in sintered W heavy alloys were discussed with regard to properties and applications in the light of the proportion of liquid phase formed during sintering. Investigations of microstructural evolution, grain size distribution and slumping. of WCu-Ni alloys were described. Effects of powder and liquid phase characteristics and process conditions were studied. A general model was proposed. DISPERSION
STRENGTHENING
TUNGSTEN-IRON-NICKEL
OF
ALUMINIDE
COMPOSITES R.M. German
et
al.
University, USA) The development
(Pennsylvania
the
arts
State
of W heavy alloys
as
substitutes for depleted IIw;tsdiscussed with reference to adiabatic shear. Note was taken of efforts to strengthen the matrix phase, by use of a Fe-N&Al matrix to attain this and the need for further strengthening. The addition of dispersoids to the Fe-Ni&l
automotive
and
was to stimulate
others.
The
non-metallurgical
MANUFACTURING TECHNOLOGY Kaufman.
(Technology
Management
industries
were
were
emphasized. for
process
rapid
of data
illustrations
were
the
on
noted.
presented
importance
regard
and
design
was
of
ferritic
which
were
structural
steel,
CURRENT
taking
Hot
densification
of
PM
and parts with to
Implementation
ferrous
plasma ferrous
alloys,
SURFACES
State University, USA) Surface ausforming of steel parts was outlined. The process is plastic deformation of the surface of steel in a metastable austenitic condition asquenched to just above the M, temperature. This improves surface densification and gives a microstructure with high strength and resistance to rolling contact fatigue. Wear properties were also improved. BY A
MICROSTRUCTURAL AFFECTING
of
and
novel
STRUCTURAL B. Weiss
RELATIONSHIPS
PERFORMANCE
OF PM
PARTS
et
al.
(Ilniversity
of
Vienna,
Vienna, Austria.) Degradation
in mechanical
PM parts, due to porosity, materials that
was
than
properties
compared
discussed.
properties
is
with
the
reduction
in
cross-section.
Interconnected
to be more detrimental
pores.
Inhomogeneity
also had an effect., region acting
as crack
inclusions.
inhomogeneities material
K. Komatsu components
effect
of
is great.er at higher
basic
AND MECHANICAL OF STAINLESS STEELS et
al.
(Engineered of
properties steels
SYSTEM
was
M.L. Kelley. (General
mechanical
of
Sintered
Co., USA.)
investigation
mechanical
effects
sites,
pores or
strength.
CORROSION PROPERTIES
An
The
of
of high
initiation
which may also start at secondary slag
It was
in
isolated
porosity
of
with
reduction
sintering
Corp, ISA)
and
Processing
by traditional
stainless
LOW PRESSURE
Motors
with
Structure property relationships
porosity
(Pennsylvania
DIE LUBRICATION
for
used
reviewed
was discussed.
load bearing
OF HIGH DENSITY
G.R. Stoudt.
processes were
pores were shown
R.A. Queeney,
HIGH VOLUME
Carp, Petaluma, I‘SA.)
consolidation.
disproportionate
processes
STEEL
HOT
PROCESSES
materials
shown
in ferrous
WEARRESISTANCE
fatigue low alloy
unconventional
and for product
AUSFORMED
and with
AND ADVANCED
densification
wrought
hnovations
Wear
compared
pseudo-HIP
will be required.
manufacture.
core.
properties
of
effects
PM
was
as
which
reviewed
hardness
note
was discussed.
EXTERNAL
the
Surface
C and there was high ductility
such
use will be made of computing decision
used.
was
sintor
particular
Management
critically
to changes
and
was
powder
press,‘single
techniques
AND FUTURE
management
single
AG
high density
and
MANUFACTURE
facilitate
A
methods,
NEW MANAGEMENT
Extensive
reported.
with
3.5’kMost,eel
Some
analysis was
of parts
prealloyed
A Bose. (Parmatech
control
new technology.
PARTS
Production
L)emag
PM
Process
Dependence
dissemination showed
in
discussed.
and statistical
computers
(Mannesmann Germany.)
DENSIFICATION
and Associates, USA ) Possible future developments
SINTERING
Huttentechnik, from
and
BY
STATE
K.H. Lindner.
in
PARTS
AND THE NEW
compaction
PM GEARS
SOLID
90 Rockwell
A REVIEW OF FUTURE
SM.
lower
systems.
method
use of metal powders.
manufacture
HEAVY ALLOYS
R.M. German.
object
Future
AND
IN LIQUID TUNGSTEN
industries,
applications,
were
were given from food
H.A. Tews. (Technology Associates, USA)
alloys
GRAIN SIZE VARIATION
chemical
in non-
applications,
Examples
monitoring
Tokyo, Japan.) It was reported that repeated powder forging had been used to prepare nonequilibrium and nano-structured materials, A novel machine for repeated powder
A
uses of metal powders,
described.
J.M. Torralba
pressures due to reduced die wall The system could be fitted to the feed shoe and utilises existing
HIGH DENSITY
pressed/non-sintered
POWDERS
allows
ENHANCED
SF. Claeys. (Pyron Corp, USA.) PREPARATION
system ejection friction. powder control
POWDERS
Mechanical alloying
system, for use 111 where powder and, was described. The
1000
corrosion
of 410L
after
belt
described. hour
properties
salt
and
and
or
434L
vacuum
Results
of
the
spray
tests
on
were present,ed.
MPR April 1997 47
size distribution
gas pressure, alloy atomizer geometry.
were found to be composition
and
matrix, such as oxides or introduced by mechanical was investigated.
carbides, alloying,
A perspective powders
on metal
SOME
USES OF METAL
SURPRISING
A die lubrication PM parts production or die are heated,
FROM
OF ALUMINIUM
MECHANICALLY
ALLOY
ALLOYED
Unusual
and et al. (Polytechnic
University
of Madrid, Madrid, Spain. ) It was reported that a 2014 Al alloy powder had been prepared from elemental powders by mechanical alloying followed by extrusion at 500°C. with an extrusion ratio of 25:1, and heat treatment to optimize properties and structure. Powders and consolidated alloy were characterized and a high degree of homogeneity was reported. PRODUCTIVE
MECHANICAL
BY REPEATED J.
Kihara
et
POWDER al.
AL.LOYING
FORGING
(llniversity
of
Tokyo,
forging, with a load capacity of 500 tons was used to process Cu-Ag and a range of Al alloys.
Tungsten
heavy
DISTORTION SINTERED Upadhiya,
PHASE
(Pennsylvania
State University, USA) Shape control and dimensional
stability
in sintered W heavy alloys were discussed with regard to properties and applications in the light of the proportion of liquid phase formed during sintering. Investigations of microstructural evolution, grain size distribution and slumping. of WCu-Ni alloys were described. Effects of powder and liquid phase characteristics and process conditions were studied. A general model was proposed. DISPERSION
STRENGTHENING
TUNGSTEN-IRON-NICKEL
OF
ALUMINIDE
COMPOSITES R.M. German
et
al.
University, USA) The development
(Pennsylvania
the
arts
State
of W heavy alloys
as
substitutes for depleted IIw;tsdiscussed with reference to adiabatic shear. Note was taken of efforts to strengthen the matrix phase, by use of a Fe-N&Al matrix to attain this and the need for further strengthening. The addition of dispersoids to the Fe-Ni&l
automotive
and
was to stimulate
others.
The
non-metallurgical
MANUFACTURING TECHNOLOGY Kaufman.
(Technology
Management
industries
were
were
emphasized. for
process
rapid
of data
illustrations
were
the
on
noted.
presented
importance
regard
and
design
was
of
ferritic
which
were
structural
steel,
CURRENT
taking
Hot
densification
of
PM
and parts with to
Implementation
ferrous
plasma ferrous
alloys,
SURFACES
State University, USA) Surface ausforming of steel parts was outlined. The process is plastic deformation of the surface of steel in a metastable austenitic condition asquenched to just above the M, temperature. This improves surface densification and gives a microstructure with high strength and resistance to rolling contact fatigue. Wear properties were also improved. BY A
MICROSTRUCTURAL AFFECTING
of
and
novel
STRUCTURAL B. Weiss
RELATIONSHIPS
PERFORMANCE
OF PM
PARTS
et
al.
(Ilniversity
of
Vienna,
Vienna, Austria.) Degradation
in mechanical
PM parts, due to porosity, materials that
was
than
properties
compared
discussed.
properties
is
with
the
reduction
in
cross-section.
Interconnected
to be more detrimental
pores.
Inhomogeneity
also had an effect., region acting
as crack
inclusions.
inhomogeneities material
K. Komatsu components
effect
of
is great.er at higher
basic
AND MECHANICAL OF STAINLESS STEELS et
al.
(Engineered of
properties steels
SYSTEM
was
M.L. Kelley. (General
mechanical
of
Sintered
Co., USA.)
investigation
mechanical
effects
sites,
pores or
strength.
CORROSION PROPERTIES
An
The
of
of high
initiation
which may also start at secondary slag
It was
in
isolated
porosity
of
with
reduction
sintering
Corp, ISA)
and
Processing
by traditional
stainless
LOW PRESSURE
Motors
with
Structure property relationships
porosity
(Pennsylvania
DIE LUBRICATION
for
used
reviewed
was discussed.
load bearing
OF HIGH DENSITY
G.R. Stoudt.
processes were
pores were shown
R.A. Queeney,
HIGH VOLUME
Carp, Petaluma, I‘SA.)
consolidation.
disproportionate
processes
STEEL
HOT
PROCESSES
materials
shown
in ferrous
WEARRESISTANCE
fatigue low alloy
unconventional
and for product
AUSFORMED
and with
AND ADVANCED
densification
wrought
hnovations
Wear
compared
pseudo-HIP
will be required.
manufacture.
core.
properties
of
effects
PM
was
as
which
reviewed
hardness
note
was discussed.
EXTERNAL
the
Surface
C and there was high ductility
such
use will be made of computing decision
used.
was
sintor
particular
Management
critically
to changes
and
was
powder
press,‘single
techniques
AND FUTURE
management
single
AG
high density
and
MANUFACTURE
facilitate
A
methods,
NEW MANAGEMENT
Extensive
reported.
with
3.5’kMost,eel
Some
analysis was
of parts
prealloyed
A Bose. (Parmatech
control
new technology.
PARTS
Production
L)emag
PM
Process
Dependence
dissemination showed
in
discussed.
and statistical
computers
(Mannesmann Germany.)
DENSIFICATION
and Associates, USA ) Possible future developments
SINTERING
Huttentechnik, from
and
BY
STATE
K.H. Lindner.
in
PARTS
AND THE NEW
compaction
PM GEARS
SOLID
90 Rockwell
A REVIEW OF FUTURE
SM.
lower
systems.
method
use of metal powders.
manufacture
HEAVY ALLOYS
R.M. German.
object
Future
AND
IN LIQUID TUNGSTEN
industries,
applications,
were
were given from food
H.A. Tews. (Technology Associates, USA)
alloys
GRAIN SIZE VARIATION
chemical
in non-
applications,
Examples
monitoring
Tokyo, Japan.) It was reported that repeated powder forging had been used to prepare nonequilibrium and nano-structured materials, A novel machine for repeated powder
A
uses of metal powders,
described.
J.M. Torralba
pressures due to reduced die wall The system could be fitted to the feed shoe and utilises existing
HIGH DENSITY
pressed/non-sintered
POWDERS
allows
ENHANCED
SF. Claeys. (Pyron Corp, USA.) PREPARATION
system ejection friction. powder control
POWDERS
Mechanical alloying
system, for use 111 where powder and, was described. The
1000
corrosion
of 410L
after
belt
described. hour
properties
salt
and
and
or
434L
vacuum
Results
of
the
spray
tests
on
were present,ed.
MPR April 1997 47