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Welding Process: It is the permanent joining of two materials usually metals by coalescence which is induced by a combination of temperature, pressure and metallurgical conditions. Types of Joints: There are 5 types of joints which are described as follows: 1. Butt Joint: The parts lie in the same plane and are joined to their edges. 2. Corner Joint: Parts form a right angle and are joined at the corner of the angle. 3. Lap Joint: It consist of two overlapping parts. 4. Tee Joint: One part is perpendicular to the other in the shape of letter T. 5. Edge Joint: Parts are parallel with atleast one of their edge is common and the joint is made at the common edges. Types of Welds: There are different types of welds which are described ahead: 1. Fillet Weld: It is used to fill the edges of plates created by corner, lap and tee joints. 2. Groove Weld: It usually require that the edges of the pats be shaped into a groove to facilitate w...

Bulk Forming Processes: Bulk refers to workparts with low surface area to volume ratio. Bulk Forming uses heavy machine to apply three dimensional stresses. There are 4 basic operations used for bulk deformation: Rolling Forging  Extrusion Wire & Bar Drawing 1. Rolling: Deformation process in which work thickness is reduced by compressive forces exerted by two opposite rolls. Variations in rolling are described ahead: A. Types of Rolling Based on Workpiece Geometry: I. Flat Rolling: It is used to reduce thickness of a rectangular cross-section. II. Shape Rolling: It is used to deform workpiece into contoured cross-section. B. Types of Rolling Based on Work Temperature: I. Hot Rolling: The material is heated to a uniform elevated temperature to achieve significant deformation. Parts are free from residual stresses. II. Cold Rolling: Hot materials (like plates or sheets) are further flatten by cold rolling to prepare t...

Sheet Forming Processes: The manufacturing process in which shape change is achieved through plastic deformation. Keep in mind that the increase in temperature will results in decrease in strength, increase ductility and decrease the rate of strain hardening. Sheet Material   →   which have large surface area to volume ratio. Bulk Material   →   which have lesser surface area to volume ratio. There are three basic operation in sheet metal working: Cutting or Shearing Bending  Deep Drawing 1. Shearing (Cutting) Operations: It is the mechanical Cutting of materials without the formation of chips or the use of burning or melting. There are different types of cutting operations: A. Simple Shearing: When metal sheets are to be cut along a straight line between two cutting edges. B. Slitting: It us the lengthwise shearing operation used to cut coils of sheet metal into several rolls of narrower width. ...

Fabrication of Plastics: Plastics can be mold into different products and have ingredients like paints, varnish, adhesives and other polymer matrix composites. Plastics are divided into two types; Thermosets  →  It undergoes a curing process during heating and shaping which causes a permanent chemical change. Thermoplastic  →  Their chemical structure remains unchanged on heating. Shaping Processes for Plastics: Shaping process for polymer are as follows: 1. Blow Molding: A molding process in which air pressure is used to inflate soft Plastics into mold cavity. This process is accomplished in two steps: Fabrication of a starting tube from heated plastics called as Parison. Inflation of tube to the desired final shape. Formation of Parison is done by two process which we describe below: A. Extrusion Blow Molding: A blow molding on which prison is made by extruder. Steps are as follows: Extrusion of Parison. Parison is t...