Engineering Questions with Answers - Multiple Choice Questions
Manufacturing Processes – Ultrasonic Machining – 2
1 - Question
Which of the following materials is not used as abrasive in ultrasonic machining?
Explanation: Abrasive materials used as abrasive in USM are as follows; • Al2O3 • SiC • B4C • Boronsilicarbide • Diamond.
2 - Question
Pick the odd one out.
a) Frequency of vibration
b) Abrasive size
c) Coolant flow rate
d) Flow strength of work material
Explanation: 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 - Question
Which of the following is not the component of USM machine?
a) Slurry delivery
d) Lead screw
Explanation: 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 - Question
In USM, horn is used for amplifying the vibrations.
Explanation: 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 - Question
The transducer for USM works on how many principles?
Explanation: 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 - Question
The horn or concentrator can have how many different shapes?
d) It can have any shape
Explanation: 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 - Question
Which of the following is not machined by USM?
a) Brittle metals
d) Ductile materials
Explanation: USM is used for machining; • hard metallic alloys • brittle metallic alloys • semiconductors • glass • ceramics • carbides.
8 - Question
For which of the following operations USM is not used?
a) Round shaped hole
b) Square shaped hole
c) Irregular shaped hole
Explanation: USM is used for machining;
• round shaped holes
• square shaped holes
• irregular shaped holes
• surface impressions.
9 - Question
USM has low material removal rate.
Explanation: Limitations of USM are as follows;
• Low MRR
• Rather high tool wear
• Low depth of hole.
10 - Question
USM machine uses _____ axis table.
Explanation: 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.