Manufacturing Processes Multiple Choice Questions on “Micromachining – 1”.
1. Micro machining processes (MMPs) are used to increase selectivity, accuracy, performance, etc. parameters.
a) True
b) False
Answer: a
Clarification: Micro machining processes (MMPs) are used for;
(1) Minimizing energy and materials used in manufacturing Reduction of power budget
(2) Faster devices
(3) Increased selectivity and sensitivity
(4) Improved accuracy and reliability
(5) Cost/ performance advantages
(6) Integration with electronics, simplifying systems.
2. Choose the odd one out.
a) micro-AJM
b) micro-USM
c) micro-AWJM
d) micro-EDM
Answer: d
Clarification: Among all the processes, micro-AJM (micro abrasive jet machining), micro-USM (micro ultrasonic machining) micro-AWJM (micro abrasive water jet machining) use mechanical energy to remove the material; whereas, micro-EDM (micro eletro discharge machining) process uses thermal energy to remove the material.
3. Choose the odd one out.
a) micro-turning
b) micro-milling
c) micro-EBM
d) micro-grinding
Answer: c
Clarification: Micro-turning, micro-milling and micro-grinding are traditional material removal processes; whereas, micro-EBM (micro electron beam machining) process is one of the advanced manufacturing processes.
4. Choose the odd one out.
a) Micro-EBM
b) LBM
c) EDM
d) ECMM
Answer: d
Clarification: Micro-EBM, LBM (laser beam machining), EDM (electron discharge machining) processes uses thermal energy for removing material and ECMM (electrochemical micro machining) process uses chemical energy to remove material.
5. Choose the odd one out.
a) EBM
b) ECM
c) EDM
d) LBM
Answer: d
Clarification: Among all the above mentioned processes, electric discharge micromachining (EDM), electron beam micromachining (EBM) and electrochemical machining (ECM) are used only for electrically conducting materials; whereas, laser beam micromachining (LBM) process can be used for both conducting and non-conducting materials.
6. Thermal deformation of the workpiece is the major problem in micromachining.
a) True
b) False
Answer: a
Clarification: Following are the major problems faced during micromachining;
•Mechanical deformation
•Thermal deformation
•Surface integrity
•Gap between tool and work piece
•Coordinate shift in tool handling.
7. In abrasive jet machining, material is removed by shear as well as brittle deformation of the material.
a) True
b) False
Answer: a
Clarification: If the KE of the abrasive particle is high enough, then it will remove the material by shear deformation in case of ductile workpiece material and by brittle fracture if workpiece material is brittle.
8. Holes up to _____ deep can be drilled without using AJM process.
a) 10 nm
b) 45 mm
c) 66 μm
d) 100 μm
Answer: c
Clarification: In AJM, holes up to 66 μm deep can be drilled without employing any special techniques. This process is also useful for producing microcavity.
9. Fused ion beam machining process is based on binding energy of atoms in the workpiece material.
a) True
b) False
Answer: a
Clarification: Fused ion beam machining process is nothing but knocking out atoms from the work-piece surface by the kinetic momentum transfer from incident ion to the target atoms. In this process removal of atoms occur when the actual energy transferred exceeds the usual binding energy.
10. In thermal advanced micromachining process, intense heat is produced.
a) True
b) False
Answer: a
Clarification: In this process, localized intense heat is produced which increases temperature of the workpiece in a narrow zone (i.e.Beamdiameter), equal to its melting or vaporization temperature. Which leads to removal of material at micro/nano level in the form of debris (irregular shaped particles or spherical globules).