CONVENTIONAL AND NON CONVENTIONAL MACHINING DIFFERENCE

CONVENTIONAL AND NON TRADITIONAL MACHINING PROCESS

When we talk about manufacturing process it can be broadly classified as:-

• Primary manufacturing process

• Secondary manufacturing process

Primary manufacturing process includes the basic manufacturing process such as casting, powder metallurgy etc.

Secondary manufacturing process includes removal of material from products obtained from primary manufacturing process (machining). This can also be divided into two parts:-

• Conventional machining process
• Non traditional machining process.

Both the process of machining has some advantage and few disadvantages and suits according to application. In conventional machining process there is direct contact between the work piece and tool. Such process leads to tool wear in good amount due to friction because of direct contact between tool and work piece. The examples are

• Drilling
• Boring
• Grinding
• Cutting
• Broaching
• Lathe operation
• Milling,etc

In non traditional machining process, there is no contact between tool and the work piece. Various other form of energy are used in such processes i.e. indirect energy sources These are used in high strength to weight ratio application. Also used for aerospace and nuclear applications. In short we can say that this type of machining can be performed when complex and intricate shapes is to be obtained. The examples of such process are:-

• Abrasive jet machining (AJM)
• Water jet machining (WJM)
• Ultrasonic jet machining (USM), etc.

BASIC DIFFERENCE BETWEEN CONVENTIONAL AND NON TRADITIONAL MACHINING

1. Conventional machining process

There is direct contact between the tool and work piece.           

fig:-conventional machining

• The cutting action takes place on application of cutting force applied by tool. 
• Under any condition tool is harder than the work piece. 
• Material removal takes place by chip formation by shear deformation (may be microscopic chip formation). 
• Less tool life, due to repeated wear of tool. 
• Any material can be machined. 
• Large amount of noise is produced due to metal and tool contact on cutting. 
• Accuracy is not very high. 
• More care and precaution is aught to be taken for such machining process. 
• Overall cost is less/capital cost is less.
• No need of highly skilled operators.

2.  Non traditional machining

• There is no direct contact between the tool and the work piece. 
• Cutting action takes place by different forms of energy. For example in elecrto chemical machining, chemical reaction is basic process of machining where chemical dissolution of work piece occurs. 
• Tool may or may not be harder than work piece. 
• Material removal may occur by chip formation or by chemical deposition or other form. 
• No noise is produced, since no contact and no friction is involved between tool and work piece. 
• High accuracy is obtained and good surface finish. 
• Tool life is long, since no wear and tear takes place. 
• Skilled labor is to be employed. 
• Costlier process than conventional machining processes.
• This type of machining is helpful in conditions where high temperature rise in work piece during operation is a major problem. In NTM, flow of electrolyte removes heat from working region.
• On the other hand high production rate due to costlier equipment and skilled operators add to its disadvantage.