Conventional Manufacturing Processes PDF

CONVENTIONAL MANUFACTURING PROCESSES Dr. A. Manmadha Chary Associate Professor Department of Mechatronics Engineering, IFHE University, Hyderabad, Telangana, India. 1  What is Fabrication ?  Fabrication is t...

CONVENTIONAL MANUFACTURING PROCESSES Dr. A. Manmadha Chary Associate Professor Department of Mechatronics Engineering, IFHE University, Hyderabad, Telangana, India. 1  What is Fabrication ?  Fabrication is the processes to create component parts that can be used to make a product or structure, as well as the process of constructing an item from standardized parts.  Fabrication synonyms are manufacturing, production, forming, framing, making etc..  Manufacturing is the processing of converting raw materials into a finished product that can be sold to a consumer.  The material as found in nature is called raw material.  The process of making a product is called manufacturing and the process is called manufacturing process. 2  What do we mean by digital? Digital describes electronic technology that generates, stores, and processes data in terms of two states: positive and non-positive. Positive is expressed or represented by the number 1 and non-positive by the number 0. Thus, data transmitted or stored with digital technology is expressed as a string of 0's and 1's. Digital data can be used to store very complex information Examples of digital data are digital images, digital video, video games, web pages and websites, social media, databases, digital audio such as MP3, electronic documents and electronic books. 3 Introduction of Digital Fabrication Fabrication can be done manually, but the processes are often automated these days with the use of computer aided designs (CAD) that can be programmed into computer numerical control (CNC) and 3D-Printing technologies that can communicate directly with machines on the shop floor. It can reducing lead times, costs and material usage while improving accuracy and quality. The most common forms of digital fabrication technologies are:  CNC Machining: where shapes are cut out of metals with using programs  3D Printing: where objects are built up out of layers of metal or plastic 4  Digital Fabrication Digital fabrication is a design and manufacturing workflow where digital data directly drives manufacturing equipment to form various part geometries. This data most often comes from CAD (computer-aided design), which is then transferred to CAM (computer-aided manufacturing) software. Digital Fabrication makes it possible to fabricate and manufacture as a functional tool instead of conventional machines. It is expected that this will become the backbone of all future design and fabrication initiatives. 5  Modern Product Development Process Upon successful completion of the course student will be able to:  Develop a prototype – virtual and physical models  Design using CAD/CAM tools  Production using conventional machines, CNC and 3D Printing technologies This course is helpful to become a Entrepreneur and Innovator 6 Manufacturing Process and its interaction with the 5 M’s Men Methods Manufacturing Machinery Process Product Material Money Classifications of Manufacturing Processes 8  Manufacturing Processes Manufacturing Processes are broadly classified in to five groups: Casting Machining Forming Powder metallurgy Joining Casting Process 10  Casting Process Casting is a manufacturing process the molten material is poured into a cavity of the desired shape and size of the product to be produced, allowing it to solidify. Cavity Desired shape/ End product The cavity is made in a suitable material held in a box called mould. After solidification, the end product is extended from the mould  Casting process Below figure shows a metal casting process in which the cavity in sand is filled with the molten metal. Examples of the products that are manufactured by the casting process are frying pans, machine bases, automobile engines, carburetors and gun barrels.  Machining The processes of removing the unwanted material from a given workpiece to give it required shape is known as machining. The removal of unwanted material may be done by a manual process or by using a machine called machining tool, and using tools called cutting tools. 14  Machining  Using the machining process, it is possible to manufacture components with very close dimensional tolerances, which cannot be obtained by the other methods of manufacturing.  Examples: Gears, automobile parts, and nuts and bolts.  When machining is used for cutting metals, it is commonly referred to as metal cutting process.  Some examples of metal cutting process are drilling, turning, milling and grinding.  Lot of material is wasted as scrap in the machining process. 15 Machining 16 Machining - Lathe Lathe equipped with a variety of attachments and accessories to facilitate the machining and to perform the specialized tasks.  Machining Turning Turning is the most basic lathe operation in which excess material from the given work piece is removed to reduce its diameter. FACING  Facing is the operation of machining the end or face of the job held in a chuck or face plate.  Facing is used for reducing the length of the workpiece  Facing operation is carried out using turning tool  The operation involves feeding the tool perpendicular to the axis of rotation of the work piece from outer surface to centre.  Length of tool travel is half the diameter of the job. KNURLING  A knurling operation, carried out on a lathe, is used to produce regular patterned rough surface  Knurling is the process of embossing a diamond shaped regular pattern on the surface of work piece using a tool called Knurling tool.  Knurling is not a metal cutting process. It is a method of squeezing the metal hard enough to cause plastic movements of metal in to peaks and troughs. Grooving  Groove or grooving is the process of producing a narrow groove on the surface of a cylindrical job.  The diameter is workpiece is reduced slightly from the surface over a narrow width.  The job is revolved at a slow speed and the grooving tool is fed straight into the work by rotating the cross-slide screw.  There is no feed in groove operation Parting  Parting is the operation of cutting a work piece into two parts.  If slow feed is used, the tool will not cut continuously but will ride on the surface for a revolution or two, and then bite in suddenly. This phenomenon is known as hogging. Chamfering  Chamfering is the operation of beveling the sharp ends of the work piece to avoid any injuries to the person using the finished product.  It is provided better look, to enable nut to start freely on treaded workpiece.  Chamfering angle usually 450 Taper Turning A tapered job is one whose diameter decreases or increases gradually so that it assumes conical shape. Tan α = D1-D2/2L α = angle of taper, D1 = larger diameter in mm, D2 = smaller diameter in mm, L = Length of taper in mm. The conicity K of the taper is defined as K = D1-D2/L Taper turning by Swiveling the compound rest The compound rest has a circular base graduated in degrees, which can be swiveled at any angle. Thread cutting  It is the operation of producing a helical groove of specific shape, say ‘V’ or square on a cylindrical surface.  Thread cutting operation is done on lathe using a single point tool called thread cutting tool.  Forming Forming process encompasses a wide variety of techniques, which make use of suitable force, pressure or stresses like compression, tension, shear or their combinations to cause a permanent deformation of the material to give it the required shape. In forming process, no material is removed and wasted, but is only displaced and deformed. Examples of metal forming process included, rolling, forgoing, drawing, extrusion etc. Examples kitchen utensils, wires, cold drink bottle caps, collapsible tubes, rails, etc. Forming 29  Forming Rolling Process Theprocess of shaping metals and alloys into semi finished or finished condition by passing between the rolls is known as rolling. Thisprocess involves the plastic deformation of the metal in which the thickness of the metal reduced, while the length and width are increased  Forming Extrusion Process  It a block of metal is reduced in cross section by forcing it to flow through a die orifice under high pressure.  The extrusion process may be done either in cold or in hot condition.  If extrusion process is done at room temperature or slightly elevated temp. , it is called cold extrusion process. Metal forming process 32  Powder Metallurgy o In powder metallurgy, fine powdered materials are blended, pressed into a desired shape in a die and then heated in a controlled atmosphere to bond the contacting surfaces of the particles and get the desired properties. o Examples: gears, tungsten wires for electric bulbs, cutting tools, etc. o The size of the product that can be made by this process ranges from tiny balls for ballpoint pen tips to parts weight up to 50kg. o The products manufactured by this process have good dimensional accuracy and finish. o The products usually do not require any further processing. Powder Metallurgy 34  Joining  In this process, two or more pieces are joined together to produce the required shape and/or size of the product.  Before joining, the components may be manufactured by any of the process disused earlier.  The joint can be permanent, semi permanent or temporary.  The permanent joining can be done by fusing the metals together.  For this kind of joining, metal is locally heated or melted and filler material may be used.  Examples of permeant joining process include welding, brazing and soldering  Joining  The temporary joining of the components can be done using nuts, bolts, screws, etc.  Adhesive are also used to make temporary joints. 36  Joining Brazing is a joining process that uses a filler metal to join two base metals together at temperatures above 840 degrees Fahrenheit (450 º C). Soldering is a joining process that uses a filler metal to join two base metals together at temperatures below 840 (450 º C). Riveting Metal Joining Process 38 Welding Joining  Welding process can be defined as the process of metallurgically joining two pieces of metals by fusing to produce essentially a single piece of the metal.  The welding process joins two pieces of metal by applying intense heat or pressure or both to melt the edges of the metal so that they fuse permanently.  In welding filler material may also be used.  The heat required for the process of welding can be obtained by using an electric arc, electric current, gas flame or chemical reaction. Non-conventional Machining 40  Allied Activities The manufacturing activity, in addition, requires some allied activates to produce the finished product. The three important activities are:  Measurement  Assembly  Property changing Measure app in iPhone 41  Measurement  Each product must have a defined size, shape and other characteristics as per the design specifications.  To manufacture the product to the specified size, the size must be measured and checked during and after the manufacturing process.  This involves measuring size, smoothness and other features, in addition to their checking.  These are called measurement and inspection. 42  Assembly More than 20,000 parts are put together to make a car, below figure shows a car with its major parts. 43  Assembly The process of putting the parts together to form the product, which performs the desired function, is called assembly. An assemblage of parts may require some parts to be joined together but assembly should not be confused with the joining process. Most of the products cannot be manufactured a single unit, they are manufactured as different components using one or more of the manufacturing processes, and these components are assembled to get the desire product. 44  Property changing  In many situations during manufacturing, we required to change the properties of the material being used.  A hard material is difficult to shape by cutting , forming, etc.  If we can soften it before shaping and re-harden after the desired shape and size is obtained, the manufacturing become easy.  It is possible to alter the properties of some material such as hardness by subjecting material to a specific process.  Steel and other ferrous materials are the best examples of such materials. 45 Selection of manufacturing process  A component or product can be manufactured by more than one process.  We have alternatives of several processes for the manufacture of a given component.  The selection of a suitable process is based on the following considerations:  Volume of production  Expected quality and properties of the components  Technical viability of the process  Economy 46  Types of production Based on the quality of product, manufacturing activity can be classified under the following three categories: 1. Job shop production 2. Batch production 3. Mass production 47  Job shop production  Low volume of production and variety of work characterize job shop production.  Job shop production is commonly used to meet specific customer orders requiring one or very few numbers of the product having a very specific design and specifications.  Examples of the products made from job shop production include a space vehicle, a special tool, an easy chairs of ones comfort, etc. 48  Batch production  Batch production involves the manufacture of medium quantity of an item or product.  The orders for the product may be repetitive or non-repetitive.  Typical examples of the products made in batch production include textbooks, furniture, and so on. 49  Mass production  Mass production is characterized by manufacture of identical products in bulk quantities.  In mass production environment, the entire organization is dedicated for the manufacture of a particular type of production.  Examples of mass production are pens, refills, screws, cars and scooters.  Since the machines and equipment are involved in the manufacture of single type of production  It must be for special purpose rather than for general purpose and hence the investment required for machine tools and equipment is high. 50 Thank you 51