Question

) A 2.5 in diameter through hole is to be cut in a block of Copper(1) by electrochemical machining. The block is 2.0 in thick. To speed the cutting process, the electrode tool will have a center hole of 2.25 in, which will produce a center core that can be removed after the tool breaks through. If the efficiency of the ECM operation is 90%, what current is required to complete the cutting operation in X2 minutes?

Answer 1

Hello the cutting operation time is 30 minutes and not X2 minutes

answer: 256.825 amps

Step-by-step explanation:

assuming for a copper block

Fr = 2.69 * 10^-4 in/amp-min

area =
`(\pi )/(u)` (
`(2.5^(2) - 2.25^(2))` = 0.93266
`in^(2)`

Fa = Fr / area = (2.69 * 10^-4) / 0.93266 = 0.000288 in/min

at 90% efficiency of ECM

Fa = Fa * 90% = 0.000288 * 0.9 = 0.00025958 I in/min equation 1

also considering block thickness and time

Fa = block thickness / time = 2/ 30 = 0.06667 in/min equation 2

equate equation 1 to equation 2

I (REQUIRED ) = 0.06667 / 0.00025958

= 256.825 amps