Nontraditional machining: Chemical milling is performed by which basic arrangement?
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AOn a universal milling machine with a form cutter
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BOn a plain horizontal milling machine
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CIn a tank containing an appropriate etching (chemical) solution
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DOn any of these conventional milling machines
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EOn a CNC vertical machining center using end mills
Answer
Correct Answer: In a tank containing an appropriate etching (chemical) solution
Explanation
Introduction / Context:Chemical milling (a nontraditional process) removes metal by controlled chemical dissolution. It is used to lighten components, create shallow pockets, and adjust thickness without conventional cutting forces or chip formation.
Given Data / Assumptions:
- Workpiece material is chemically etchable with a selected reagent.
- Maskants protect areas not to be etched.
- Process controls include time, temperature, agitation, and concentration.
Concept / Approach:Unlike mechanical milling, chemical milling occurs in a bath or spray etch chamber. The masked workpiece is immersed or sprayed, and the exposed regions dissolve at a controlled rate, producing the desired cavity depth or thinning.
Step-by-Step Solution:
Select compatible chemical etchant for the alloy.Apply maskant and pattern; bake/cure as required.Immerse or spray-etch in the tank for a calibrated time to achieve target metal removal.Verification / Alternative check:Industry practices (aerospace, electronics) use dip or spray etching lines, not conventional milling machines, for chemical milling and photochemical machining.
Why Other Options Are Wrong:Conventional milling machines use cutters, not etchants; they cannot perform chemical milling.
Common Pitfalls:Underestimating undercut and edge effects; poor masking leading to dimensional errors; inadequate neutralization and waste handling.
Final Answer:
In a tank containing an appropriate etching (chemical) solution