Manufacturing Process Notes eBook
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Unit 1 Class1 Introduction and Concepts Here we shall learn basic concepts, Defn of Manufacturing process,Product example,General classification of Mnf process, What is Mechanical working, Deformation,Stress, Ductile and Brittle metals, Classification of Mech Working-process,Concept of RCT, Hot ,Cold and Warm working. Manufacturing Process contain two words Manufacturing and Process. What is Manufacturing ,,,,,,,,,,,,,,,, Manufacturing is the conversion of raw materials into a useful item called as Product. Product is the desired or wanted material which has shape, size, colour, and moreover has Function to perform. What is a Process Process is the step by operations involved in the conversion of raw material. Ex., Coffee is the product It is used as a drink. It is to satisfy the customer. This is its function. Coffee Powder,Sugar,Water,Milk are the raw materials in addition a vessel and fuel is used for the purpose. The raw materials are converted to the drink called as coffee. This is Manufacturing. The steps involved water is taken in a vessel and heated to boiling using a heat source, then coffee powder is added and after some time it is filtered to get the decoction. To this sugar and milk are added to get the coffee. The steps involved above is the Process. Similarly Pen is a product, Shirt is a product . Now we shall try to understand what is a product. Let us take the Pen It has shape, size, colour and a function to perform ie.,writing on a paper leaving marks. Manufacturing Processes can be classified as i Casting ii Welding iii Machining iv Mechanical working v Powder Metallurgy vi Plastic Technology etc., Here we shall concentrate on one of the important process ie., Mechanical working Process. In this process the raw material is converted to a given shape by the application of external force. The metal is subjected to stress. Stress It is defined as the ratio of force to area of cross section of the material on which the force is acting. The raw material undergoes change in the shape and this is referred to as Deformation.
Deformation It is a process of changing the shape and size of the material under the influence of external force or stress. Deformation can be Elastic or Plastic in nature. Elastic deformation is a temporary one ie.,the metal undergoes change in shape and size under the influence of external load and regains the same once the load is removed. Plastic deformation is a permanent one ie.,the metal undergoes change in shape and size under the influence of external load and cannot regain the original state. Basically a Metal is used for mechanical working process. All metals which are ductile are mechanically worked. A Ductile metal is one which undergoes increase or decrease in length when external force is applied without breaking. We have sheet or wire which are obtained due to ductility property.ex., mild steel. There are brittle metals also. A brittle metal is one which will not undergo extension or decrease in length under the influence of external force but fracture or fail.ex., cast iron Classification of Metal Working Processes 1.General classification i. Rolling