engineering doctorate lubricants increase green density for given pressure and powder decrease...
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Engineering Doctorate
LubricantsLubricants
Increase green density for given pressure and powder
Decrease ejection force
Reduce die wear
Reduce density gradients
Reduce flow rate
Increase OR reduce green strength
Decrease strength after sintering
Engineering Doctorate
SinteringSintering
Engineering Doctorate
(Diagram)
Figure 6.4: In the course of sintering (a) the compact acquires
permanent strength while the volume shrinks (density
increases) as a result of (b) elimination of most pores
between particles.
Engineering Doctorate
Sintering Temperature and Time for Various Metals
Sintering Temperature and Time for Various Metals
MATERIAL TEMPERATURE (°C) TIME (Min)
Cooper, Brass and Bronze
Iron and Iron-graphite
Nickel
Stainless Steels
Alnico alloys (for permanent magnets)
Ferrites
Tungsten Carbide
Molybdenum
Tungsten
Tantium
760 – 900
1000 – 1150
1000 – 1150
1100 – 1290
1200 – 1300
1200 – 1500
1430 – 1500
2050
2350
2400
10 – 45
8 – 45
30 – 45
30 – 60
120 – 150
10 – 600
20 – 30
120
480
480
Engineering Doctorate
(Chart)
Effect of the sintered density on the mechanical properties of
powder compacts.
Engineering Doctorate
(Chart)
Effect of sintering time on density and strength of iron
compacts.
Engineering Doctorate
(Chart)
Typical effects of powder particle size and compaction on
density changes produced by sintering.
Engineering Doctorate
(Chart)
Typical effects of initial (green) density on density changes
produced by sintering (course powder compacts).
Engineering Doctorate
Liquid Phase SinteringLiquid Phase Sintering
Low Tm powder component
W-Cu (1100°C)
Low Tm product after diffusion
WC-Co @ 1420°C
Pre-alloyed powder with supersolidus sintering
Engineering Doctorate
ApplicationsApplications
Cemented carbide tools (WC-Co)
Fe-Cu or Fe-P
Cu-Sn, Fe-Cu, self-lub bearings
Alnico magnets
Dental Amalgams