
360 Fundamentals of Machining Processes
TABLE 11.1
Theoretical Removal Rates in ECM
Metal
Atomic
Weight Valence
Density
(g/cm
3
)
Removal Rate (1000 A and
100% Current Efciency
a
)
Mass (kg/h)
Volume
(mm
3
× 10
3
/min)
Aluminum
26.97 3 2.7 0.34 2.1
Beryllium
9.0 2 1.9 0.17 1.5
Copper
63.57 1 9.0 2.37 4.4
2 1.18 2.1
Chromium
51.99 2 7.19 0.97 2.3
3 0.65 1.5
6 0.32 0.78
Cobalt
58.93 2 8.85 1.1 2.1
3 0.74 1.38
Iron
55.85 2 7.9 1.04 2.3
3 0.69 1.5
Magnesium
24.31 2 1.7 0.45 4.4
Molybdenum
95.94 3 10.2 1.19 2.0
4 0.89 1.5
6 10.2 0.60 1.0
Nickel
58.71 2 8.9 1.09 2.1
3 0.73 1.3
Niobium
92.91 3 8.6 1.16 2.3
4 0.87 1.6
5 0.69 1.3
Silicon
28.09 4 2.33 0.26 1.86
Tantalum
5 16.6 1.35 1.3
Tin
118.69 2