Advanced Machining Processes Multiple Choice Questions on “Electrostream (Capillary) Drilling”.
1. In advanced machining processes, what is the full form of ES drilling?
a) Electro stream
b) Electrical shaped
c) Electron shaped
d) Electric shock
Answer: a
Clarification: In advanced machining processes, full form of ES drilling is Electrostream drilling.
2. This Electrostream drilling is used when we cannot drill which of the following type of holes?
a) Too deep holes by EDM
b) Small holes by STEM
c) All of the mentioned
d) None of the mentioned
Answer: c
Clarification: ES drilling is used to drill finer holes which are too deep to be produced by EDM and too small to be drilled by STEM.
3. What is the value of diameter of glass nozzle used in Electrostream drilling?
a) 0.01 – 0.02 mm
b) 0.025 – 0.5 mm
c) 0.5 – 0.75 mm
d) 0.75 – 1.25 mm
Answer: b
Clarification: Electrostream drilling uses a gas nozzle, whose diameter ranges between 0.025 – 0.5 mm.
4. Compared to the required diameter of the hole, how is the nozzle diameter?
a) Smaller
b) Larger
c) Same as required
d) All of the mentioned
Answer: a
Clarification: The diameter of nozzle used is smaller than the hole size required to be drilled in work piece.
5. Which of the following acts as the cathodic tool in ES drilling?
a) Titanium base
b) Platinum wire
c) Glass nozzle
d) Work piece
Answer: b
Clarification: Unlike the case of STEM process, which uses coated Ti tube as cathode, ES drilling used platinum wire as cathode electrode.
6. What is the concentration of electrolytes that are commonly used in ES drilling?
a) 1 to 10wt %
b) 12 to 20wt %
c) 23 to 30wt %
d) 34 to 50wt %
Answer: b
Clarification: Commonly used electrolytes have a concentration between 12 to 20wt %.
7. State whether the following statement is true or false regarding ES drilling.
“In ES drilling, hydrochloric acid is used for machining aluminium and its alloys.”
a) True
b) False
Answer: a
Clarification: Hydrochloric acids are used for machining Al and its alloys and sulphuric acid is recommended for other metals.
8. Which of the following are the metals, which can be machined using sulphuric acid?
a) Carbon steels
b) Haste alloy
c) Inconel
d) All of the mentioned
Answer: d
Clarification: Haste alloy, Rene alloy, Inconel, carbon and stainless steels are the materials machined using sulphuric acid.
9. What are the values of electrolyte pressure recommended for ES drilling?
a) 50 – 100 kPa
b) 100 – 250 kPa
c) 275 – 400 kPa
d) 500 – 750 kPa
Answer: c
Clarification: Electrolyte pressure values must range between 275 – 400 kPa for ES drilling to take place.
10. Which of the following parameters must be carefully monitored for satisfactory machining?
a) Acid temperature
b) Pressure
c) Concentration
d) All of the mentioned