Various Manufacturing Processes Part-1 Release date of part -2 28-10-2021

Various Manufacturing Processes Part-1

Release date of part -2 28-10-2021

INTRODUCTION

The materials, which come under the ambit of materials science, are available either from nature or from industry. Whether from nature or industry, these materials cannot be used in their raw forms for any purposeful use. The materials are generally shaped and formed into various useful components through different manufacturing processes in order to fulfill the day-to-day needs of the industries. Manufacturing converts the raw material into finished products to be used for some purposes. Manufacturing process is a fundamental area since it is of interest not only to mechanical engineers but also to engineers from other disciplines of engineering. There are various manufacturing processes by which a product can be made of each process, however, has its own limitation and restriction and owing to this reason, a particular process is adopted to certain specitied applications. Thus, while a product can be manufactured by two or more processes, the real problem is to select the most economical one amongst the alternatives. 

A detailed understanding of various manufacturing processes is thus very essential for every engineer. This helps in designing the proper product required for an engineer. An engineer would be able to assess the feasibility of manufacturing from the design point of view. One may find that more than one process is available for manufacturing a particular product and s/he can make a proper choice of the process which would require lowest manufacturing cost.

Input-Output Model

Any manufacturing process is a process of transformation of a set of input elements into a set of desired output elements. A manufacturing process can viewed as consisting of independent (input) variables and dependent variables. For example, the machine tool operator has a direct control over the input variables and can select them when setting up the variables. Independent variables are like work-piece materials, part geometry, types of machining process, tool materials, cutting parameters, tool geometry and cutting fluid, etc. Dependent variables are cutting forces, power, surface finish, size and geometry of part, tool wear and tool failure, etc.

CLASSIFICATION OF MANUFACTURING PROCESS

Manufacturing processes can be classified as under.

👉Casting, Foundry or Moulding processes

👉Forming or Metal working processes

👉Machining (metal removal) processes

👉Joining and assembly

👉Surface treatments (finishing)

👉Heat treatments

The above-mentioned groups are not mutually exclusive. For example, some finishing processes involve a small amount of metal removal or metal forming. A laser can be used for joining/metal removal/heat treatment. Occasionally, shearing is viewed as metal forming process, although it is a metal cutting process. Assembly may involve processes other than joining. Thus, the above categorization is always not perfect.

Casting is one of the oldest manufacturing processes, Casting needs molten metal and a cavity of a refractory material. The metal retains the desired shape of the mould cavity after soliditication. An important advantage of casting process is that. in a single step, material can be converted from a crude into a desired shape, in most cases, a secondary advantage is That excess or scrap material can be recycled. The process is equally suitable for the production of a very small batch and as well as on a very large scale. Casting and moulding processes are covered in the later part of this study material. There are Two types of casting classification, namely,; permanent mould (for repeated use) and non-permanent mould (for single Use).

Forming and shearing operations typically utilize material that has been previously cast or moulded. in a forming process, metal may be heated to a temperature which is slightly below the solids temperature and then a large force is applied such That the material flows and takes the desired shape. The desired shape is controlled by means of a set of tools called dies which may be completely or partially closed during the manufacture. These processes are used normally for large-scale production. In case of series operations, the final form of material is the result of all prior operations. Thus, forming and shearing modify the shape and size and improve the mechanical properties too. Forming and shearing operations are done on metals in both "hot and "cold" state, and temperature of the material during process is important with respect to its temperature of re-crystallization. Some of the metal forming processes are: rolling, drop forging, press forging, upset forging, extrusion, wire drawing, sheet metal operations, etc.

Machining and metal removing processes are linked with the removal of a specific portion to get the desired shape (or finish), the additional unwanted material is removed in the form of chips from the blank material by a cutting tool so as to obtain the final desired shape. Chips are formed when material is machined with a cutting tool. The cutting tools are mounted in machine tools, which provide the movements to the tool with respect to the job to accomplish the desired process. Material removals are normally the most expensive methods because more energy is consumed and also a lot of waste material is generated in these processes. Machining is widely used because it delivers very good dimensional accuracy and accurate surface finish. It generates accurate contours too. 

The seven basic machining processes are: shaping, drilling, turning, milling, sawing, broaching and abrasive machining. Eight basic machine tools have been developed to accomplish the basic machining processes. These are; Shapers (Planers), Drill Presses, Lathes, Boring Machines, Milling Machines, Saws, Broaches and Grinders. The machine tools are generally capable of performing more than one of the basic machining processes and other related processes with or without the help of special attachments.

Materials removed by chemical, electrical, electro-chemical or thermal sources are included in the non-conventional machining processes. These non-traditional machining processes are used when a specific surface quality, close tolerance or intricate shape is needed to be produced on very hard materials. 

Finishing processes are yet another class of processes typically employed for cleaning, removing of burrs left by machining or providing protective or decorative surface layers on the work-pieces, Surface treatment includes plating, galvanizing, anodizing, mechanical and chemical cleaning.

Heat treatment involves the heating and cooling of a metal for specific purpose of altering its mechanical and metallurgical properties and improving the performance of the metals. 

All these basic manufacturing processes have been developed so as to obtain better products at a reduced cost. Development of computers and their effect is great and has made a remarkable contribution to the effectiveness of the above processes. They have contributed greatly to both automation and designing of the process.

The details of the manufacturing processes, namely, Forming or Metal Working Processes, Machining (Metal Removal) Processes, Joining and Assembly, and Surface Treatments (Finishing) are discussed in Part-2

Follow this link to join WhatsApp group:

Group : https://chat.whatsapp.com/BFzoWdA7SD7KKB1dMgso1F

For free latest job update and industrial information blog Join job jungle group

ફ્રી માં જોબ અપડેટ  અને ઇન્ડસ્ટ્રીયલ ઇન્ફર્મેશન બ્લોગ મેળવવા માટે જોબ જંગલ ગ્રૂપ જોઈન કરો🔧🔨⚙️