Method of manufacturing aluminide sheet by thermomechanical processing of aluminide powders

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:872873

Hajaligol, Mohammad R ^[1]; Scorey, Clive ^[2]; Sikka, Vinod K ^[3]; Deevi, Seetharama C ^[1]; Fleischhauer, Grier ^[1]; German, Randall M ^[4]

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1. Midlothian, VA
2. Cheshire, CT
3. Oak Ridge, TN
4. State College, PA

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr.ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: AC05-84OR21400
• Assignee: Philip Morris Incorporated (New York, NY)
• Patent Number(s): US 6030472
• OSTI ID: 872873
• Country of Publication: United States
• Language: English

Related Subjects

method
manufacturing
aluminide
sheet
thermomechanical
processing
powders
powder
metallurgical
process
preparing
intermetallic
alloy
composition
iron
nickel
titanium
manufactured
electrical
resistance
heating
elements
improved
temperature
ductility
resistivity
cyclic
fatigue
oxidation
strength
sagging
entirely
ferritic
microstructure
free
austenite
weight
32
optional
additions
ltoreq
gtoreq
05
zr
75
submicron
oxide
particles
electrically
insulating
conductive
covalent
ceramic
rare
earth
metal
cu
forming
non-densified
consolidating
roll
compaction
tape
casting
plasma
spraying
cold
rolled
rolling
increase
density
reduce
thickness
annealing
water
polymer
gas
atomized
subjecting
sieving
blending
binder
prior
consolidation
step
partially
sintered
steps
repeated
achieve
desired
properties
carried
vacuum
furnace
inert
atmosphere
final
recrystallizes
average
grain
size
10
30
stress
relief
b2
phase
range
temperature sagging
metallic alloy
average grain
optional additions
atomized powder
gas atomized
entirely ferritic
fatigue resistance
ferritic microstructure
conductive covalent
cyclic fatigue
covalent ceramic
vacuum furnace
temperature strength
heating elements
resistance heating
alloy composition
intermetallic alloy
plasma spray
oxidation resistance
temperature ductility
heating element
ceramic particles
electrically insulating
temperature range
electrically conductive
rare earth
metal sheet
grain size
earth metal
electrical resistance
inert atmosphere
electrical resistivity
plasma spraying
oxide particles
iron aluminide
titanium aluminide
cold rolled
cold rolling
annealing steps
powder metallurgical
ceramic particle
tape casting
temperature oxidation
rolled sheet
annealing step
metallurgical process
sheet thickness
phase temperature
roll compaction
stress relief
consolidation step
thermomechanical processing
resistance heat
mechanical process
aluminide powder
oxide particle
tape cast
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