250+ TOP MCQs on Ultrasonic Machining – 2 and Answers

Manufacturing Processes Multiple Choice Questions on “Ultrasonic Machining – 2”.

1. Which of the following materials is not used as abrasive in ultrasonic machining?
a) SiC
b) Boronsilicarbide
c) Diamond
d) TiC
Answer: d
Clarification: Abrasive materials used as abrasive in USM are as follows;
• Al₂O₃
• SiC
• B₄C
• Boronsilicarbide
• Diamond.

2. Pick the odd one out.
a) Frequency of vibration
b) Abrasive size
c) Coolant flow rate
d) Flow strength of work material
Answer: c
Clarification: The process parameters which govern the ultrasonic machining process are listed below;
• Amplitude of vibration – 15 – 50 μm
• Frequency of vibration – 19 – 25 kHz
• Feed force – related to tool dimensions
• Feed pressure
• Abrasive size – 15 μm – 150 μm
• Flow strength of work material
• Flow strength of the tool material
• Contact area of the tool
• Volume concentration of abrasive in water slurry
• Abrasive material.

3. Which of the following is not the component of USM machine?
a) Slurry delivery
b) Transducer
c) Concentrator
d) Lead screw
Answer: d
Clarification: The typical elements of a USM are as follows;
• Slurry delivery and return system
• Feed mechanism to provide a downward feed force on the tool during machining
• The transducer, which generates the ultrasonic vibration
• The horn or concentrator.

4. In USM, horn is used for amplifying the vibrations.
a) True
b) False
Answer: a
Clarification: The horn or concentrator in USM mechanically amplifies the vibration to the required amplitude of 15 – 50 μm and accommodates the tool at its tip.

5. The transducer for USM works on how many principles?
a) 2
b) 3
c) 4
d) 5
Answer: b
Clarification: The ultrasonic vibrations are produced by the transducer. The transducer is driven by suitable signal generator followed by a power amplifier. The transducer for USM works on the following principle
• Piezoelectric effect
• Magnetostrictive effect
• Electrostrictive effect.

6. The horn or concentrator can have how many different shapes?
a) 2
b) 5
c) 3
d) It can have any shape
Answer: c
Clarification: The horn or concentrator is a wave-guide, which amplifies and concentrates the vibration to the tool from the transducer. The horn or concentrator can be of different shape like
• Tapered or conical
• Exponential
• Stepped.

7. Which of the following is not machined by USM?
a) Brittle metals
b) Glass
c) Ceramics
d) Ductile materials
Answer: d
Clarification: USM is used for machining;
• hard metallic alloys
• brittle metallic alloys
• semiconductors
• glass
• ceramics
• carbides.

8. For which of the following operations USM is not used?
a) Round shaped hole
b) Square shaped hole
c) Irregular shaped hole
d) Boring
Answer: d
Clarification: USM is used for machining;
• round shaped holes
• square shaped holes
• irregular shaped holes
• surface impressions.

9. USM has low material removal rate.
a) True
b) False
Answer: a
Clarification: Limitations of USM are as follows;
• Low MRR
• Rather high tool wear
• Low depth of hole.

10. USM machine uses _____ axis table.
a) single
b) 2
c) 3
d) 5
Answer: b
Clarification: The basic mechanical structure of a USM is very similar to a drill press. However, it has additional features to carry out USM of brittle work material. The workpiece is mounted on a vice, which can be located at the desired position under the tool using a 2 axis table. The table can further be lowered or raised to accommodate work of different thickness.