Generally for tubes copper is used and for fins aluminum is used. Materials for heat transfer equipment should have good heat transfer characteristics. You can refer any material science book .
......what is the material used for evaporator and condenser coil in refrigerator.
More information is required..........evaporator coils may be made of stainless steel, plain carbon steel, copper etc...............same goes for condensers, e.g. stainless, copper, 90/10 cupro-nickel, etc.
What refrigerant are you using (India-could be R12......we hope not)), plant capacity, environmental problems, are you chilling brine, etc., etc., etc.
I certainly hope that you are not considering manufacturing a refrigeration plant, or for that matter even trying to repair one!!!
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TO BE. or NOT TO BE. That is the question!! The Bard