Engineering Questions with Answers - Multiple Choice Questions
Manufacturing Processes – Abrasive Jet Micromachining – 9
1 - Question
Which of the following technology is used for ferrite substrates?
a) Powder coating
b) Powder blasting
c) Sintering
d) Continuous powder processing
View Answer
Explanation: Another possible application of the powder blasting technology is the micro-structuring of ferrite substrates. In this case, powder blasting proved to be not only the most appropriate but also a very fast and cheaper way to get such structures.
2 - Question
Manufacturing of capillary electrophoresis chips has an application of which of the following process?
a) Ultrasonic machining
b) Chemical Milling
c) Abrasive jet machining
d) Electron beam machining
View Answer
Explanation: The device consists of a glass chip which contains a single separation channel as well as an integrated conductivity detection cell. In contrast to most micro-fluidic glass devices, the channels are not wet etched in HF but machined by AJMM which allows the creation of micro-structures below 100μm, and additionally makes parallel holes machining at very low costs outside the clean room environment.
3 - Question
Monolithic suspended micro-structure in glass was realized using _____
a) oblique AJMM
b) ion beam technique
c) photo chemical technique
d) laser beam technique
View Answer
Explanation: Complex three-dimensional and monolithic suspended microstructure in glass was realized using normal and oblique AJMM. By controlling the under etching induced by oblique AJMM blasting, millimetrer high microstructure single as scan be fabricated with an aspect ratio of 5:10, as well as free-standing monolithic 100-μm-wide structures, suspended over many millimeters.
4 - Question
The mask using SU8, _____ is applied as a micro-pattern for AJMM process.
a) SU6
b) SU7
c) SU8
d) SU9
View Answer
Explanation: A passive micro-mixer with3-dimensional feature fabricated by AJMM process by employing photo-polymer as a mask on a glass slide target. The mask using SU8, a photo-sensitive polymer is applied as a micro-pattern for AJMM process. The fabrication process involved three glass target slides and conducted multi-masking processes with four different mask patterns.
5 - Question
Which of the following is true about AJMM?
a) It is a high maintenance process
b) It is a time consuming process
c) Depths upto few microns are not possible
d) Multiple features can be machined in one operation
View Answer
Explanation: Following are the few advantages of AJMM; • Minimal tooling cost • Quick turn-around for prototyping and development work • Feature sizes down to 100 μm and featured depths to just a few microns are possible • Multiple features can be machined in one operation.
6 - Question
AJMM generates no heat.
a) True
b) False
View Answer
Explanation: Following are the few advantages of AJMM; • The process generates no heat and does not change the material properties of the work-piece • Very high pattern densities are possible • Process works well with metalized parts • Features can be of any 2D shape: square, round, designed shapes, and connected channels.
7 - Question
Abrasive jet machined features have tapered sidewalls ranging from _____
a) 5—10˚
b) 22—28˚
c) 15—30˚
d) 18—26˚
View Answer
Explanation: Unlike vertical side walls produced by ultrasonic machining, abrasive blasting machined features have tapered sidewalls ranging from 18 to 26˚, depending on several factors.
8 - Question
Maximum possible aspect ratio in AJMM is_____
a) 1:2
b) 1.5:3
c) 2:1
d) 3:1
View Answer
Explanation: In AJMM, maximum aspect ratio is 3:1 (Thickness: Diameter). Therefore, its applications are restricted to brittle materials because of low MRR in case of ductile materials.
9 - Question
Which of the following is correct about AJMM?
a) It requires no cleaning
b) It has very high accuracy
c) It tends to pollute the environment
d) The nozzle has very less wear
View Answer
Explanation: Following are the limitations of AJMM; • Sometimes additional cleaning operation is required to machine parts to remove abrasives from the surface • Machining accuracy is poor • Nozzle wear rate is high • The process tends to pollute the environment.
10 - Question
Dimensional tolerances of very less microns are possible with AJMM
a) True
b) False
View Answer
Explanation: With AJMM, feature location and dimensional tolerances down to +/-25 microns are possible. Also, features of any 2D shape: square, round, designed shapes, and connected channels can be machined.