Process selection and sequencing, Mechanical Engineering

Assignment Help:

Process Selection and Sequencing

In this, some factors, which have an influence in all processes, are discussed. The factors include size, shape complexity, tolerances and production volume.

After product consideration, selection of sequence of process is greatly influenced by the characteristics of the manufacturing processes. Hence a brief treatment of various manufacturing process right from casting to welding are discussed.

In all casting processes, a metal or alloy is melted, poured into a mold, allowed to solidify and the part thus produced is released from the mold. Very broadly, casting processes fall into two groups: expendable-mold and permanent-mold processes. Choice of process and mold material is greatly influenced by the melting point of the alloy.

All plastic deformation processes exploit the ability of metals and alloys to change shape by plastic flow. The ability to deform without fracture is highly variable. Bulk deformation processes impose material flow in all directions, and the ability to deform is expressed as workability; in sheet metal working processes deformation is essentially two-dimensional, and limits of deformation are referred to as formability. It is important to recognize that the limits of plastic deformation are the outputs of a system and these are greatly affected by the stress state prevailing in the process.

Powder processing involves a sequence of operations. The powder is produced by various techniques: reduction of an oxide, thermal decomposition, electrolysis, hydrometallurgy, or breaking up (atomizing) a melt. Particle size is controlled during powder production or by comminution; size fractions are separated by sizing. After cleaning (and possibly annealing), alloying elements and lubricants are added by blending. There are several process routes to arrive at finished parts.

Parts produced by casting, deformation, and powder processing techniques frequently require some metal removal to create the final shape, meet tolerances, or obtain the requisite surface finish. Machining may also be an economical alternative to create the shaper from a semi fabricated product such as bar or plate. Metal may be removed by chip formation or by less conventional, noncutting techniques.

A good manufacturing sequence is always determined by selecting suitable terminal points. Hence such a sequence must begin and end with part prints. Before formulating any process plan, the process engineer find out what is wanted in the final product. At the end of manufacturing sequence, the process engineer must again make reference to the part print to determine by comparison whether or not the final product can meet all design specifications.


Related Discussions:- Process selection and sequencing

Illustrate types of pipe racks, Q. Illustrate types of pipe racks? The ...

Q. Illustrate types of pipe racks? The following types of pipe racks may be required: • Interconnecting pipe rack (elevated). • Unit pipe rack (elevated). • Pipe ra

Show maximum allowable working pressure, Q. Show Maximum Allowable Working ...

Q. Show Maximum Allowable Working Pressure? The MAWP to be marked on the Section VIII nameplate is defined as the maximum gauge pressure permissible at the top of a completed v

Agriculture, i am thinking that neglecting the foot gears and put hand gear...

i am thinking that neglecting the foot gears and put hand gears instead of it in two wheelers .so what is the procedure

Corrosion in boiler, Q. Corrosion in Boiler? With proper BFW treatment,...

Q. Corrosion in Boiler? With proper BFW treatment, and maintaining pH within a certain range (9.2 to 9.4) and removing oxygen from the system, a stable passive film will be for

Isentropic flow through the nozzle, Isentropic flow through the nozzle: ...

Isentropic flow through the nozzle: In an isentropic flow through the nozzle, air flows at rate of 600Kg/hr. At inlet to the nozzle, the pressure is 2Mpa and temperature is 1

What factors are responsible for surface finish, a) Why cutting fluids are ...

a) Why cutting fluids are used for machining of metals? List different types of cutting fluids and additives for cutting  fluids. b) What factors are responsible for surface fin

Functions of the piston , Functions of the Piston To transmit forc...

Functions of the Piston To transmit force of explosion to the crankshaft. To form a seal so that high pressure gases from the combustion chamber do not escape into th

Frictional force acting on the ladder, Frictional force acting on the ladde...

Frictional force acting on the ladder: A uniform ladder having length 13m and weighing 250N is placed against smooth vertical wall with its lower end 5m from wall. The coeffi

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd