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The industries engage in manufacturing consumer goods needed by public and industrial goods needed by the companies in various industries. These are possible only if there are appropriate manufacturing technologies established in industries. Among them, the basic forms of manufacturing processes constitute a significant portion of the total infrastructural facilities of the industries. Dr.R.Panneerselvam, Professor (Retired), Pondicherry university with his forty years of teaching and research experience at Pondicherry university and earlier at Anna university, Chennai, and Dr.P.Sivasankaran, Associate Professor, Mechanical Engineering Department, Christ College of Engineering and Technology, Puducherry with his fourteen years of teaching and research experience, developed this text on ‘Manufacturing Process: A Complete Text’, which provides a comprehensive treatments of all the elements of Manufacturing Process for B.E./ B.S./B.Tech engineering degree courses. The text begins with introducing factory system, need of products made by industries, importance of manufacturing process, types of manufacturing processes and machine tools. Chapter 2 on sand casting presents history of casting, types of casting process, elements of sand casting, pattern making with topics, viz. types of patterns, types of pattern material, pattern allowances, types of sands, properties of sand-casting mould, steps of sand casting, core, and gate and its types. It is followed by a chapter on moulding machines and melting furnaces, which gives a comprehensive presentation of thermoforming moulding, injection moulding, compression moulding, transfer moulding, extrusion moulding, blow moulding, rotational moulding, hydroforming, laminating, and metal furnaces, viz. Cupola furnace, induction furnace, and open-hearth furnace. Chapter 4 presents special casting processes, which include shell casting, investment casting, ceramic mould casting, pressure diecasting, viz. hot chamber process in high pressure diecasting, cold chamber high pressure diecasting and low-pressure diecasting, and horizontal centrifugal casting, vertical centrifugal casting, CO2 casting process, stir casting, squeeze casting, full mould casting, magnetic casting, and casting techniques for single crystal components. It is followed by a presentation of different casting defects. Chapter 5 is on gas welding, which is a metal joining process. This chapter includes key terminologies of welding, gas welding techniques, viz. Air-Acetylene Welding (AAW), Oxy-Acetylene Welding (OAW), Oxy Hydrogen Welding, and Pressure Gas Welding (PGW). Next, the chapter 6 on arc welding includes

1.1 Evolution of Factory System Family-run cottage businesses transformed to the factory system, which employed a division of labour and machinery-based manufacturing process, during the Industrial Revolution. At the start of the Industrial Revolution in the late 1700s, the factory system was initially implemented in Great Britain and quickly extended around the world. The employment of machinery, initially propelled by steam or water and subsequently by electricity, is the primary feature of the factory system. When cotton spinning was mechanised, the factory system spread widely. The factory would receive raw cotton, spin it, bleach it, dye it, and weave it into finished cloth. Before the factory system, many goods, such as shoes, were crafted by expert artisans, who would typically create an entire item by hand. By contrast, factories employed a division of labour whereby most workers were either unskilled workers who moved materials and finished things or low-skilled labourers who operated machinery. From the textile industry, the factory system expanded to other sectors of the economy. To produce metal, small local forges and blacksmiths were replaced by massive furnaces and mills. Eventually, machines took the position of skilled artisans in most of the items that were produced. 1.2 Need of Products Made by Industries As time passes, the need of the products manufactured by various industries grows exponentially. This is mainly to give comfort to the people in their day-today life. Take the case of cycle, which helps people to move from one place another place. Later, it has been partially replaced by powered motor cycle, which serves the same purpose, but with power using fuel. This gives the comfort of travelling long distance in less time. Presently, there are high powered two wheelers, which can travel at a speed of more than 100 km per hr. If one compares the growth of the technology from cycle to high powered two-wheeler, there is a tremendous improvement in terms of end uses to satisfy customers. The goods that are produced by the industries are classified into consumer goods and industrial goods. Consumer goods are completed items that are sold to and utilised by customers, whereas industrial goods are raw materials used to produce other products. Industrial products are purchased and utilised for

2.1 Tracing History of Casting The manufacture of end products, viz. two-wheeler, four-wheeler, fan, washing machine, fridge, grinding machine, water cooler, etc., in companies requires many components. The components of these products have different shapes and sizes. Casting is a manufacturing process, which gives shape and size to a component of interest by pouring molten metal, which is in red hot state into a mould, which is designed such that its internal shape and size exactly match with the external shape and size of the component of interest. Casting is a very old art form that dates back thousands of years before the start of written history. Findings from the archaeological record show that the casting process was used more than 6000 years ago, or around 3000 BC. It is assumed that the moulds consisted of two pieces of pottery joined by a rope and featuring a hole to allow the molten metal to be poured into them. It is assumed that early hunting tools and weapons were made in this manner The Greeks and Romans made the casting process in artform to make bronze status, in which hollow wax has been used. Every component of a product was casted individually. The core of the mould was composed of clay and coated in wax. Next, a layer of clay was heated to melt the wax inside, and then the clay was heated once again to burn off any leftover wax. Melted metal was poured into the region where the wax had been removed once the mould was stable and ready, which is a process like contemporary investment casting. China started producing tools, bowls and many industrial items using casting around 1000 BCE. In specific, they produced farm tools and weapons. After several centuries, the casting process reached European counties to make gun, bullets, etc. With the advent of industrial revolution, the casting process became as a usual manufacturing process, what is seen today. Later, several metals, which are used in casting have been invented to produce high quality products with increased end of life for them. Over a period, metal casting underwent development. Casting procedures advanced quickly along with improvements in metal-heating and melting techniques. Gold was the first metal to be casted because of its low melting point and malleability. China made significant contributions to the development of casting when it discovered sand casting and iron, also referred to as pig iron.

3.1 Introduction The different moulding machines are listed below. • Thermoforming moulding • Injection moulding • Compression moulding • Transfer moulding • Extrusion moulding • Blow moulding • Rotational moulding • Hydroforming • Laminating The melting furnaces, which feed molten metal to fill mould cavities are listed below. • Cupola furnace • Induction furnace • Open hearth furnace This chapter presents the different moulding machines and melting furnaces. 3.2 Thermoforming Moulding To develop unique packaging solutions, thermoforming is the process of stretching a heated plastic sheet over a mould, then trimming, and assembling the design once the sheet has cooled as shown in Fig.3.1. The hot thermoplastic is stretched over the surface of the mould using the two thermoforming processes, viz. vacuum forming and pressure forming. A thermoforming machine is a sizable piece of industrial machinery that allows us to vacuum-form a plastic sheet onto an object as the sheet is being moulded. Thermoforming machines are used and benefited by a variety of businesses to efficiently package their products. The material used to produce parts by thermoforming machines is thermoforming plastic. Numerous thermoforming polymers are available for use in particular applications.

4.1 Introduction There are special casting processes as listed below. i. Shell casting ii. Investment casting iii. Ceramic mould casting iv. Pressure diecasting v. Centrifugal casting vi. CO2 casting process vii. Stir casting viii. Squeeze casting ix. Full mould casting x. Magnetic casting xi. Micro casting 4.2 Shell Casting The complete aspect of shell casting has been already presented under shell pattern in Section 2.4.1.3. For the purpose of reinforcement, it is reproduced here. Sand that has been covered in resin is used as the mould in the casting process known as shell mould casting, or just shell moulding. After pouring molten metal into the mould’s cavity, the mould vaporizes to produce a hard shell. This process will have two or more patterns to give shape and size to the final product to be casted. The steps of making shell mould are presented below. 1. In the case of two pieces of patterns, make each pattern using iron or steel. 2. A mould is made once the pattern has been made. In this stage, a lubricant is applied after both pattern components have been heated. After that, each pattern piece is placed at the top of a dump box which contains resin covered sand. Then the pattern will absorb the sand. 3. Invert the dump box to free the excess sand particles sticking the patten.

5.1 Introduction A common method for combining metals in a wide range of applications is welding. Welding takes place in a variety of places, including factories and workshops, as well as outside on rural farms and construction sites. Basic welding techniques can be easily learnt, and the processes involved are quite straightforward to understand. The molecular joining of metals is called welding. When two or more pieces of metal are joined together uniformly such that the joint’s strength is greater than the combined strength of the individual components is known as a weld. 5.1.1 Key Terminologies of Welding Four materials and other two elements are needed for welding, which are as listed below. i. Metals ii. Heat source/ flame iii. Filler/ flux material iv. Electrode v. Air shield vi. Coatings To create a single piece of metal, the metals are heated to their melting point while being kept out of the air. A filler metal is then added to the heated area. It can be done under pressure or without pressure. In some cases, filler material need not be used. Air is used as a shield to cover the welding zone from oxidation. 5.1.1.1 Metals Metals are the workpieces, which are to be joined. These metals may be similar or dissimilar. There are many situations wherein two or more workpieces are to be joined. Consider internal combustion engine in which valve timing gears are fixed over cam shaft. The fixing of the cam over the cam shaft is carried out by welding. Here, the workpieces are the cam and the cam shaft

6.1 Introduction One of the various fusion welding techniques used to combine metals is arc welding. It melts and joins metals by producing a high temperature using an electric arc. An electric arc is created between a base metal and a consumable or non-consumable electrodede by a power source. The types of arc welding methods are listed below. i. Gas shield tungsten arc welding ii. Metal arc welding iii. Submerged arc welding iv. Gas shield metal arc welding v. Flux Cored Arc Welding (FCAW) vi. Electrode-Slag Welding (ESW) vii. Electrode-Gas Welding (EGW) viii. Arc Stud Welding (SW) ix. Carbon Arc Welding (CAW) x. Atomic Hydrogen Welding (AHW) 6.2 Gas Shield Tungstan arc Welding An electric arc formed between a tungsten electrodede and the metal that needs to be joined starts the welding process. The arc melts the metal while protecting the weld from airborne impurities with a cloud of argon, helium gas, or carbon dioxide. A separate filler rod can be used to add additional filler metal. An inert gas, such as argon or helium, surrounds a non-consumable tungsten electrodede during the arc welding method known as tungsten inert gas welding (TIG). If more weld metal is needed, an additional filler rod can supply it. To prevent overheating and excessive erosion of the tungsten electrodede, a direct current is employed with the electrodede negatively charged.

    7.1 Introduction By passing an electrical current through two pieces of plain metal, they can be joined together using resistance welding. The electrical resistance of the metals due to the contact resistance between them, and the electrical current combine to produce the required welding heat. The manufacturing sector frequently uses resistance welding, a type of welding, to join metal sheets and components. In order to create a weld, a high current must be passed through the metal combination to heat it up and eventually melt the metal at a localised points that are chosen based on the electrode and/or workpiece designs. To limit the contact area at the weld interfaces and, in certain cases, to forge the workpieces, a force is always provided prior to, during, and following the application of current. The resistance welding process is classified into the following types. i. Resistance spot welding (RSW) ii. Resistance seam welding (RSEW) iii. Upset welding (UW) iv. Projection welding (PW) v. Percussion welding (PEW) vi. Flash welding (FW) 7.2 Resistance Spot Welding (RSW) The automotive and aviation industries make extensive use of resistance spot welding, or simply spot welding. Extremely low voltage and very high current are used in this kind of welding. A wide variety of metals, including copper (Cu), titanium (Ti), magnesium (Mg), aluminium (Al), and their alloys are welded by this welding method. RSW is typically used to join thin sheets of metal, either similar or different, in a lap joint form. A few drawbacks of RSW include electrode degradation, misalignment, voids, and cracking. RSW welding of thicker metal sheets is typically challenging due to the ease with which the heat flows in the surrounding metal.

8.1 Introduction Every fusion welding procedure that uses a heat source capable of producing incredibly high weld input levels is known as high energy density welding. For welding, the density of the energy obtainable from a heat source is frequently more significant than the source’s absolute energy. Electron beam welding (EBW) and laser beam welding (LBW) are the two main categories of high energy density welding technologies. In both procedures, a very high-intensity beam is used as the heating source for the weld, and this beam’s energy is highly concentrated due to optical or electromagnetic lenses, respectively. These processes have an energy density of roughly 1010–1013 W/m2. The energy density of typical arc welding procedures is roughly 5 x108 W/m2. As fast-moving electrons in EBW and photons in LBW collide with the workpiece, their kinetic energy is converted into heat. This causes melting, vaporisation, and heating in a very small region. Due to non-uniform weld metal shrinkage or thermal contraction, penetration into the workpiece can be significant. This results in deep, thin, parallel-sided fusion welds with narrow heat-affected zones and little angular distortion. Since the electron beam welding is nearly always done autogenously, the joint fit needs to be flawless. This welding is classified into the following types. i. Plasma arc welding ii. Electron Beam welding (EBW) iii. Laser bean welding (LBW) 8.2 Plasma Arc Welding An electric plasma arc and a non-consumable electrode are used in the fusion welding method known as plasma arc welding (PAW) to fuse metals together. The electrode is typically constructed of thoriated tungsten, just like in TIG. It is an excellent option for welding thin metals and producing deep, narrow welds because of its distinctive torch design, which provides a more focused beam than TIG welding. Compared to conventional procedures, plasma welding is frequently used to weld tough metals like aluminium, stainless steel, and others. This method, like oxy-fuel welding, can also cut metal (plasma cutting), which gives fabricators and manufacturers another useful tool.

9.1 Introduction In continuation to a comprehensive presentation of the fusion welding techniques in Chapters 5, 6, 7 and 8, this chapter presents advanced welding/ joining techniques, which are as listed below. i. Cold metal transfer ii. Wire arc additive manufacturing (WAAM) iii. Thermal spraying iv. Thermit welding v. Ultrasonic welding vi. Friction welding vii. Diffusion bonding viii. Soldering ix. Brazing x. Adhesive bonding 9.2 Cold Metal Transfer A subset of gas metal arc welding is called Cold Metal Transfer (CMT). When it detects a short circuit, it reduces the weld current and retracts the weld wire, which causes a drop-by-drop deposit of weld material. The cold metal transfer was designed for thin materials and necessitates tight weld parameter control. Cold Metal Transfer combines a cutting-edge wire feed technology with high-speed digital management to create a regulated manner of material deposition with little heat input. In order to achieve enough energy to melt a tip of filler wire as well as the base material, the wire feed rate and cycle arcing phase are regulated. The cold metal transfer process has two primary features, viz. the occurrence of a short circuit in a stable and controlled manner, and the point of short circuit with low current correlating to a low heat input

10.1 Introduction Many of the industrial components/ products are produced by forging corresponding workpieces. Carbon steel, alloy steel, tool steel, aluminium, stainless steel, duplex steel, copper, and brass are among the materials that can be forged. Many factors will cause the forging process to vary. For example, the forging operation for titanium will differ from that for stainless steel. Steel is a material that can be formed into a wide variety of items when heated to high temperatures, around 1200–1300 degrees Celsius. The metal’s grains lengthen in the direction of flow during the industrial forging process. The metal’s hardness is significantly increased as a result. The flow lines in the completed component will lie where the component will experience the most stress due to well-designed forging. The forging is classified into cold forging and hot forging. 10.2 Stress-Strain Curve of Metal Forming Process When a metal is applied with a stress (force per unit area), it experiences a strain. The formula for the stress that is applied on a metal component is given below.

11.1 Introduction  By passing a metal piece through a gap between two rollers that are revolving in opposite directions (clockwise or anticlockwise), metal can be shaped into a thin, long sheet by the process known as rolling. The working piece of the material to be created should have a thickness smaller than the gap between the two rollers. Rolling is used to convert more than 95% of ferrous and non-ferrous metals and alloys into forms that are suitable for use. Rolling of metals gives the shapes, viz. plate, sheet, strip, foil, and various sections such as rail, beam, channel, angle, bar, rod, and seamless pipe. By allowing the material to travel through the space between two revolving cylindrical rolls, considerable compressive stress is applied to the material throughout the rolling process, which results in permanent deformation. The rolls are kept at a constant distance from one another. They can have grooves or flat. Using an electrical drive system (motor, gearbox, spindle, and couplings), the rolls are rotated in the opposite direction. The input material enters the gap between the rolls from one end and exits the other end with a decreased cross-section. The roll gap area remains less than the cross-sectional area of the input material (rolling stock), depending on the direction of rotation of the rolls. In most cases, the material must be passed through the revolving rolls multiple times to produce the final shape that is desired. The two rolls are brought closer to one another on each pass, or the material is allowed to travel through various sets of roll gaps with decreasing cross-sectional area. The assembly of rolls mounted on bearings is held in bearing blocks, also known as chocks, which are held between the spaces between two cast frames, also known as housings. The complete setup is called rolling mill stand. A rolling mill, also known as a rolling plant, is made up of one or more rolling stands along with other relevant and essential machinery for producing final rolled goods from a single or comparable class of raw materials.

12.1 Introduction This chapter presents topics on drawing, stretching and extrusion under bulk transformation process. Tensile forces are used in the manufacturing process of drawing to extend materials, viz. plastic, glass, and metal. The material takes on the required thickness and shape as it is drawn, or dragged. Sheet metal drawing, and wire, bar and tube drawing are the two categories of drawings. Drawing is one of the most remarkable shaping techniques used in sheet metal stamping. During the drawing process, a blank’s surface area is forced into a new shape by controlled metal flow due to stress. As the metal enters the cavity, flow happens. Basically, drawing occurs when the blank’s exterior profile changes during the metal’s formation. One of the complicated yet most efficient methods for forming sheet metal is drawing. Because tension is involved in the drawing process, some stretching will occur, but the goal is to form the sheet metal with as little stretching as possible. Tension and metal thinning during the stretching process cause a blank’s surface area to increase. Do not mistake stretching for drawing. The blank changes shape as the metal flows through the die during drawing. The blank edge does not move inward during stretching. Except for the fact that stretching dies, in contrast to most embossing dies, use a high-pressure binder to limit and stop metal flow. Like a drawing pad, a binder purposefully prevents the metal from flowing inward. Stretching dies are used in the production of automotive parts, viz. fenders, roofs, and hoods. Extrusion is the process of forcing material through a die with the desired cross-section to generate components with a fixed cross-sectional profile.

13.1 Introduction Any metal that is shaped into thin, malleable sheets is called sheet metal. The sheets come in a variety of predetermined thicknesses, known as gauges, and are made of materials ranging from titanium to brass. Although sheets can vary in thickness from fractions of a millimeter to several inches, most are typically less than ¼ inch thick. In sheet metal forming, different techniques are used to exert force on a sheet of metal to plastically change it into the required shape and changing its geometry instead of removing any material. Because sheet metal can be bent or stretched into a wide range of intricate shapes, it can be used to create sophisticated structures that are both very strong and use little material. The most economical forming method available today for producing large quantities of parts is sheet metal forming. On the other end of the spectrum, it can be manually operated in metal workshops for small series items or fully automated in factories. It is a flexible, reliable, and superior process that produces precise metal parts with little material waste. Sheet metal forming components are everywhere in our daily lives, from metal cans to protective housing for hardware. Sheet metal process is an extensive cold working procedure that involves shearing, punching/cutting, folding, riveting, splicing, and moulding such as vehicle bodies using metal sheets that are typically less than 6mm in thickness. 13.2 Sheet Metal Characteristics The characteristics of the sheet metal are as listed below. i. Because of its ductility, sheet metal may be shaped into a wide variety of shapes without shattering or cracking. ii. Because it allows the material to be bent, stretched, and stamped throughout the production process, its malleability is essential for manufacturing. iii. Another crucial element is the thickness of the sheet metal, which can vary from incredibly thin to several centimeters. Typically, a gauge number is used to indicate the thickness of a sheet metal. A lower gauge number denotes a thicker material and a higher gauge number denotes a thinner material. Sheet metal can be used for a wide range of purposes, from heavyduty machinery parts to lightweight electronic enclosures.

14.1 Introduction The other topics of the metal forming are as listed below. a. Stretch forming operation b. Formability of sheet metal c. Test methods These topics are presented in this chapter. 14.2 Stretch Forming Operation A sheet metal is simultaneously stretched and curved over a die during the stretch forming process to create big shaped parts. Stretch forming is done using a stretch press, where jaws are gripped firmly to fix a sheet metal along its edges. To stretch the sheet, the grasping jaws are individually coupled to a carriage that is drawn by a hydraulic or pneumatic force. A stretch form block, also known as a form die, is the tooling utilized in this procedure. It is a solid contoured piece that the sheet metal will be pressed against. The most common type of stretch press is vertically orientated with the form die situated on a press table , which will be elevated by a hydraulic ram into the sheet. Tensile stresses build and the sheet plastically deforms into a new shape when the form die is pressed into the firmly gripped sheet. The sheet is pulled horizontally around the form die by the gripping jaws of a horizontal stretch press, which mounts the form die sideways on a stationary press table

15.1 Introduction This chapter presents the working principles and applications of special forming processes. The different special forming processes are as listed below. i. Hydro forming ii. Rubber pad forming iii. Multi-point die forming iv. Warm/hot forming v. Solid granular medium forming vi. Metals pinning vii. Explosive forming viii. Magnetic pulse forming ix. Peen-forming x. Super plastic-forming xi. Micro forming xii. Incremental forming 15.2 Hydro Forming The word “hydroforming” describes the metal forming procedures where the material blank is deformed by hydraulic pressure. There are difficulties with sealing, pressurization schedule, anticontamination in the pressure system, and cleaning the workpiece and equipment after direct contact between the pressurized fluid and the blank material. In certain instances, the necessary hydroforming pressure may surpass 350 MPa, contingent upon the setup of the process and the thickness of the material. Hydroforming procedures are divided into two categories, viz. sheet metal hydroforming and tube hydroforming, depending on the geometry of the blank. 15.2.1 Sheet Metal Hydro forming When it comes to tooling, sheet metal hydro forming is less complicated than typical sheet metal stamping. Only one side of the tooling, typically the lower side needs to be created for the sheet metal hydro forming process. The hydro forming

16.1 Introduction This chapter presents the definition of plastic, its types and characteristics. For each type of plastic, its molecular structure, properties, advantages and disadvantages and applications are presented. 16.1.1 Origin of Plastic Charles Goodyear discovered vulcanization, a process that increased rubber’s elasticity and resilience, in 1839, which resulted with the discovery of plastic. One of the earliest known polymer combinations was the creation of Charles Goodyear. Celluloid, or Parkesine was discovered in 1855 by Alexander Parkes. This substance is a blend of cellulose nitrate and camphor/lime. Additionally, it was the first thermoplastic to become rigid when cold and flexible when heated. In the years that followed, several noteworthy discoveries were made, such as the separation of PVC in 1835 by the French physicist Victor Regnault, the invention of the first synthetic polymer (or industrial plastic) in 1869 by John Wesley Hyatt, and the introduction of transparent food packaging in 1900 by Edward Brandenberger. 16.1.2 Plastic and its Constituents Plastic is a class of materials that is utilised in electronics, construction, medical equipment, packaging, etc., because of its extreme versatility. This synthetic or semi-synthetic material can be moulded using a variety of methods. It is created from petrochemicals or natural materials like cellulose or starch. The basic components are chemically altered to create polymers, which are lengthy sequences of molecules. Then, these polymers can be moulded using blow, extrusion, or injection moulding techniques to create a variety of shapes. Another name for some plastics is resins. Based on their chemical makeup, plastics can be divided into two primary categories, viz. thermoplastic and thermoset/ thermosetting plastic. The thermoplastics can be moulded, melted, and remoulded repeatedly. Thermoset/ thermosetting plastic cannot be heated again. Polymers come in a variety of forms, both synthetic and natural. Among the materials most frequently used in the creation of plastic are coal, natural gas, cellulose, starch, crude oil, and salt. Plastics are mostly made by two processes that call for certain

17.1 Introduction Pouring liquid plastic into a specific container or mould and allowing it to solidify into the desired shape is known as plastic moulding. After that, a variety of uses for these plastic moulds are possible. The different types of plastic moulding/ forming processes are listed below. i. Injection moulding ii. Compression moulding iii. Extrusion moulding iv. Transfer moulding v. Blow moulding vi. Rotational moulding vii. Film blowing viii. Vacuum bag forming ix. Thermoforming x. Bonding of thermoplastics 17.2 Injection Moulding Using a pre-made mould and plastic resin, thermoplastic injection moulding is a manufacturing technique that produces completely functional items. It falls into a few subcategories, like fast injection moulding, which is best used for finetuning prototypes before approving a product for mass production. Plastic resin of any engineering grade can be used for thermoplastic injection moulding. General resins are used to make early prototypes or less important portions of a product, whereas engineering grade resins are usually employed to construct final prototypes before to manufacture. The term “general resins” refers to materials such as TPE, ABS, nylon, PET, polypropylene, and polyethylene. Reels of engineering grade include ultem, valox, noryl, and lexan. Product developers can experiment with various materials and surface treatments for their products because of the wide variety of plastic resins that can be processed via thermoplastic injection moulding.