Model Test Paper( AMM)

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 With a muri or flow based approach (as

 Senior management used in the TPS with suppliers). to agree and discuss their  Sort out as many of lean vision the visible quality

 Management problems as you can, as brainstorm to identify well as downtime and project leader and set other instability problems, objectives and get the internal scrap acknowledged and its  Communicate plan management started. and vision to the workforce  Make the flow of  Ask for volunteers to parts through the system form the lean or process as continuous as implementation team (5-7 possible using workcells works best, all from different and market locations departments) where necessary and  Appoint members of avoiding variations in the the lean manufacturing operators work cycle implementation team  Introduce standard  Train the work and stabilize the Implementation Team in the work pace through the various lean tools - make a point of trying to visit other non competing businesses that have implemented lean

 Select a Pilot Project system to implement – 5S is a good place to start  Start pulling work through the system, look at  Run the pilot for 2–3 the production scheduling months - evaluate, review and move toward daily and learn from your orders with kanban cards mistakes  Even out the  Roll out pilot to other production flow by factory areas reducing batch sizes,  Evaluate results, increase delivery encourage feedback frequency internally and if  Stabilize the positive possible externally, level results by teaching internal demand supervisors how to train the  Improve exposed new standards you've quality issues using the developed with TWI tools methodology (Training  Remove some Within Industry) people (or increase quotas)  Once you are satisfied and go through this work that you have a habitual again (the Oh No !! program, consider moment) introducing the next lean tool. Select the one that gives you the biggest return for your business. 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