Model Test paper( AMM)

Note: Ques 1 is compulsory & Do 5 question from 7 question.

Ques 1(a) What is lean manufacturing?

Lean manufacturing, lean enterprise, or lean production, often simply, "lean", is a

production practice that considers the expenditure of resources for any goal other

than the creation of value for the end customer to be wasteful, and thus a target for

elimination. Working from the perspective of the customer who consumes a product

or service, "value" is defined as any action or process that a customer would be

willing to pay for.

Ques:1 (b) What is role of dielectric in EDM?

The functions of a dielectric fluid in Electric Discharge Machining process are as

follows:

• To serve as a spark conductor in the spark gap between the tool and work

material.

• To act as a coolant to quench the spark and to cool the tool and work piece.

• To carry away the condensed metal particles and to maintain the gap for

continuous and smooth operation

Ques: 1(c) What are the similarities between Agile & lean Manufacturing?

Lean and agile manufacturing are both ultimately focused on increasing business

sustainability in the high-cost manufacturing sector. Both are answers to challenges

faced by historical manufacturers, and both provide opportunities for smaller

players to compete with larger, entrenched competitors. Both concepts rely heavily

on statistical analysis, computerized information systems and open communication

between internal and external stakeholders. Because of this, both of these concepts

are tied to modern advances in production technology and are perfectly suited to the

tools and resources available to modern managers. Lean and agile design

considerations are both early stage planning decisions, influencing the way in which

organizations are structured from the accounting system all the down to the factory

floor.

Ques 1(d)How ultrasonic vibration are produced?

Ques 1(e)What is Group Technology?

Group Technology or GT is a manufacturing technique[1] in which the parts having

similarities in Geometry, manufacturing process and/or functions are assembled

together. GT is based on a general principle that many problems are similar and by

grouping similar problems, a single solution can be found to a set of problems, thus

saving time and effort.

The group of similar parts is known as part family and the group of machineries

used to process an individual part family is known as machine cell. It is not

necessary for each part of a part family to be processed by every machine of

corresponding machine cell. This type of manufacturing in which a part family is

produced by a machine cell is known as cellular manufacturing. The manufacturing

efficiencies are generally increased by employing GT because the required

operations may be confined to only a small cell and thus avoiding the need for

transportation of in-process

Ques1(f)what is role of abrasive grit in USM?

Ques:1(g) what is difference between batch & mass production?

The difference between the two is that batch productions is a form of production

that is applied to a large number of items all at once whilst mass production is the

same but made one at a time from mass produced parts

Ques:1(h) what is laser beam machining ?

Laser beam machining (LBM) is an unconventional machining process in which a

laser is directed towards the work piece for machining. Since the rays of a laser

beam are monochromatic and parallel it can be focused to a very small diameter

and can produce energy as high as 100 MW of energy for a square millimeter of

area. It is especially suited to making accurately placed holes. It can be used to

perform precision micro-machining on all microelectronic substrates such as

ceramic, silicon, diamond, and graphite. Examples of microelectronic micro-

machining include cutting, scribing & drilling all substrates

Ques:1(i)Explain Computer-integrated manufacturing (CIM)

Computer-integrated manufacturing (CIM) is the manufacturing approach of using

computers to control the entire production process.[1][2] This integration allows

individual processes to exchange information with each other and initiate actions.

Through the integration of computers, manufacturing can be faster and less error-

prone, although the main advantage is the ability to create automated

manufacturing processes. Typically CIM relies on closed-loop control processes,

based on real-time input from sensors. It is also known as flexible design and

manufacturing

Ques: 1(j)List 3 application of USM?

Ques2 (a)What are process parameter in ECM?

Solution:

:

Ques2 (b) Explain Modelling of MRR in ECM?

Ques3: Explain principle of EDM with Neat diagram. What is selection process of

dielectric fluid in EDM?

Electric discharge machining (EDM) is a chipless metal removal process also known

as Spark Erosion Process. In an EDM metal removal operation, a dielectric fluid is

an important and essential working medium. Dielectric fluid is flushed through the

spark gap or supplied to the gap through a hole in the tool or from external jets. In

some operations the fluid is supplied through openings in the work piece if feasible.

The flow of this working medium is designed to take in specific directions to favour

the machining operations.

The essential requirements in the selection of the dielectric fluid for Electric

Discharge Machining (EDM) are as follows:

• It should have a stable and sufficient dielectric strength to act as insulation

between the tool and the work piece.

• It should have a low viscosity for smooth flow and high wettability.

• It should be chemically inert, so that the tool, work piece, container are not

attacked.

• It should be able to deionise immediately after the spark discharge.

• It should have a high flash point.

• It should not emit toxic vapours and should not have unpleasant odours.

• It should not alter its basic properties under operating conditions of temperature

variations, contamination by metal particles and products of decomposition.

• It should be economical for use.

Ques 4: What are the various approach of Lean Manufacturing? Explain them

briefly.

With a tools-based approach

Senior management to agree

and discuss their lean vision

Management brainstorm to

identify project leader and

set objectives

Communicate plan and

vision to the workforce

Ask for volunteers to form

the lean implementation

team (5-7 works best, all

from different departments)

Appoint members of the lean

manufacturing

implementation team

Train the Implementation

Team in the various lean

tools - make a point of trying

to visit other non competing

businesses that have

With a muri or flow based approach (as

used in the TPS with suppliers).

Sort out as many of the

visible quality problems as

you can, as well as

downtime and other

instability problems, and

get the internal scrap

acknowledged and its

management started.

Make the flow of parts

through the system or

process as continuous as

possible using workcells

and market locations

where necessary and

avoiding variations in the

operators work cycle

Introduce standard work

and stabilize the work pace

implemented lean

Select a Pilot Project to

implement – 5S is a good

place to start

Run the pilot for 2–3 months

- evaluate, review and learn

from your mistakes

Roll out pilot to other

factory areas

Evaluate results, encourage

feedback

Stabilize the positive results

by teaching supervisors how

to train the new standards

you've developed with TWI

methodology (Training

Within Industry)

Once you are satisfied that

you have a habitual

program, consider

introducing the next lean

tool. Select the one that gives

you the biggest return for

your business.

through the system

Start pulling work through

the system, look at the

production scheduling and

move toward daily orders

with kanban cards

Even out the production

flow by reducing batch

sizes, increase delivery

frequency internally and if

possible externally, level

internal demand

Improve exposed quality

issues using the tools

Remove some people (or

increase quotas) and go

through this work again

(the Oh No !! moment)

Ques 5: What is EBM. Explain mechanism & principle of EBM with neat sketch.

Ques 6 Explain AJM principle with neat sketch.what are the application &disadvantage

of AJM?

Solution:

Abrasive jet machining (AJM), also known as abrasive micro-blasting, pencil blasting

and micro-abrasive blasting,[1] is an abrasive blasting machining process that uses

abrasives propelled by a high velocity gas to erode material from the workpiece.

Common uses include cutting heat-sensitive, brittle, thin, or hard materials. Specifically it

is used to cut intricate shapes or form specific edge shapes.

Material is removed by fine abrasive particles, usually about 0.001 in (0.025 mm) in

diameter, driven by a high velocity fluid stream; common gases are air or inert gases.

Pressures for the gas range from 25 to 130 psig (170–900 kPag) and speeds can be as

high as 300 m/s.

AJM machines are usually self-contained bench-top units. First it compresses the

gas and then mixes it with the abrasive in a mixing chamber. The gas passes

through a convergent-divergent nozzle before entering the mixing chamber, and

then exits through a convergent nozzle. The nozzle can be hand held or mounted in

a fixture for automatic operations.

Nozzles must be highly resistant to abrasion and are typically made of tungsten

carbide or synthetic sapphire. For average material removal, tungsten carbide

nozzles have a useful life of 12 to 30 hours, and sapphire nozzles last about

300 hours. The distance of the nozzle from the workpiece affects the size of the

machined area and the rate of material removal

The main advantages are its flexibility, low heat production, and ability to machine

hard and brittle materials. Its flexibility owes from its ability to use hoses to

transport the gas and abrasive to any part of the workpiece.[3][4]

One of the main disadvantages is its slow material removal rate; for this reason it is

usually used as a finishing process. Another disadvantage is that the process

produces a tapered cut