The operation of heating the green
compact at high temperature in a controlled atmosphere (Reducing
atmosphere which protects oxidation of metal powders). The Sintering
increases the bond between the particles and therefore strengthens a
powder metal compact. Sintering temperature and time of sintering
depends on the type of powders and the strength required in a final
product. The Sintering temperatures usually 0.6 to 0.8 times the melting
point of powders.
Type of powder Sintering Temperature Time
Aluminium & Alloys 370 – 520 C 24 hrs
Copper, Brass, Bronze 700 – 900 C 30 Mins
Iron 1025 – 1200 C 30 Mins
Stainless Steel 1180 C 20 – 40 Mins
Tungsten Carbide 1480 C 20 – 40 Mins
Spark Sintering:
The process of simultaneous pressing & Sintering
of metal powders by high energy electric spark. This spark is discharged
from capacitor bank & removes the surface contaminants from powder
particles. This cause the particles to form a solid cohesive mass.
Immediately after spark, the current is continued for about 10 Seconds,
with high temperature which further strengthens the bond used for
sintering Aluminium, Copper, Iron and Stainless Steel.
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