Design for Advanced Manufacturing: Technologies and Processes [LaRoux K. Gillespie] Design for Advanced Manufacturing and millions of other books are. Advanced Manufacturing Processes, Systems and Technologies (AMPST 99) [ M. K. Story time just got better with Prime Book Box, a subscription that delivers . Handbook- III Additive Manufacturing and Surface. Engineering. Editors on advanced manufacturing processes and techniques. . This is a book project edited by myself and Professor J.P. Davim for CRC Press. Modeling.
|Language:||English, Arabic, French|
|Genre:||Health & Fitness|
|ePub File Size:||26.43 MB|
|PDF File Size:||11.65 MB|
|Distribution:||Free* [*Sign up for free]|
This book provides details and collective information on working principle, process mechanism, salient features, and unique applications of various advanced. This book provides an overview of different chemical processes like chemical milling, photochemical milling and electropolishing. From inside the book Design of Work and Development of Personnel in Advanced Manufacturing QR code for Advanced manufacturing technology.
Advanced Machining and Manufacturing Processes
SlideShare Explore Search You. Submit Search. Successfully reported this slideshow. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime. Upcoming SlideShare. Like this document? Why not share! Embed Size px.
Start on. Show related SlideShares at end. WordPress Shortcode. Published in: Full Name Comment goes here. Are you sure you want to Yes No. Maggie Fletcher Want to preview some of our plans? Lorena Cochran Want to preview some of our plans? Show More. NaNi Sankranthi. No Downloads. Views Total views. Actions Shares. Embeds 0 No embeds.
No notes for slide. Syllabus Unit I: Shape tube Electrolytic machining, EJT: Electrochemical Grinding, ECH: Micro Machining Processes Diamond micro machining, ultrasonic micro machining, micro electro discharge machining Unit V: Additive Manufacturing Processes Introduction and principles, Development of additive manufacturing Technologies, general additive manufacturing processes, powder based fusion process, extrusion based system, sheet lamination process, direct write technologies Unit VI: UNIT 1.
Roll forming 2. High velocity hydro forming, 3.
High velocity Mechanical Forming, 4. Electromagnetic forming, 5. Spinning, 7. Flow forming, 8. Shear Spinning Insem-Aug. The rolls rotate as illustrated in Figure 1.
The basic process shown in our figure 1. A closely related process is shape rolling, in which a square cross section is formed into a shape such as an I-beam.
Most rolling processes are very capital intensive, requiring massive pieces of equipment, called rolling mills, to perform them. The high investment cost requires the mills to be used for production in large quantities of standard items such as sheets and plates. Most rolling is carried out by hot working, called hot rolling, owing to the large amount of deformation required.
Hot-rolled metal is generally free of residual stresses, and its properties are isotropic. Disadvantages of hot rolling are that the product cannot be held to close tolerances, and the surface has a characteristic oxide scale.
Steel making provides the most common application of rolling mill operations. Let us follow the sequence of steps in a steel rolling mill to illustrate the variety of products made. Similar steps occur in other basic metal industries.
Roll Forming 5. YEOLA just solidified. While it is still hot, the ingot is placed in a furnace where it remains for many hours until it has reached a uniform temperature throughout, so that the metal will flow consistently during rolling. For steel, the desired temperature for rolling is around C F. The heating operation is called soaking, and the furnaces in which it is carried out are called soaking pits. From soaking, the ingot is moved to the rolling mill, where it is rolled into one of three intermediate shapes called blooms, billets, or slabs.
Abloom has a square cross section mm 6 in or larger. A slab is rolled from an ingot or a bloom and has a rectangular cross section of width mm 10 in or more and thickness 40 mm 1. A billet is rolled from a bloom and is square with dimensions 40 mm 1.
These intermediate shapes are subsequently rolled into final product shapes. Blooms are rolled into structural shapes and rails for railroad tracks. Billets are rolled into bars and rods.
These shapes are the raw materials for machining, wire drawing, forging, and other metalworking processes. Slabs are rolled into plates, sheets, and strips. Hot-rolled plates are used in shipbuilding, bridges, boilers, welded structures for various heavy machines, tubes and pipes, and many other products. Figure 3.
Further flattening of hot-rolled plates and sheets is often accomplished by cold rolling, in order to prepare them for subsequent sheet metal operations. Cold rolling strengthens the metal and permits a tighter tolerance on thickness. In addition, the surface of the cold-rolled sheet is absent of scale and generally superior to the corresponding hot-rolled product. These characteristics make cold-rolled sheets, strips, and coils ideal for stampings, exterior panels, and other parts of products ranging from automobiles to appliances and office furniture.
Rolling Process Roll forming is one of the most common techniques used in the forming process, to obtain a product as per the desired shape.
The roll forming process is mainly used due to its ease to be formed into useful shapes from tubes, rods, and sheets. In this process, sheet metal, tubes, strips are fed between successive pairs of rolls, that progressively bent and formed, until the desired shape and cross section are attained. The roll forming process adds strength and rigidity to lightweight materials, such as aluminum, brass, copper and zinc, composites.
Roll forming processes are successfully used for materials that are difficult to form by other conventional 6. YEOLA methods because of the spring back, as this process achieves plastic deformation without the spring back.
In addition, the roll forming improves the mechanical properties of the material, especially, its hardness, grain size, and also increases the corrosion rate. The material to be rolled is drawn by means of friction into the two revolving roll gap. The compressive forces applied by the rolls reduce the thickness of the material or changes its cross sectional thickness of the material. The geometry of the product depend on the contour of the roll gap. Roll materials are cast iron, cast steel and forged steel because of high strength and wear resistance.
Hot rolls are generally rough so that they can bite the work, and cold rolls are ground and polished for good finish. In rolling the crystals get elongated in the rolling direction.
Flat rolling is illustrated in Figures 3. It involves the rolling of slabs, strips, sheets, and plates—workparts of rectangular cross section in which the width is greater than the thickness.
In flat rolling, the work is squeezed between two rolls so that its thickness is reduced by an amount called the draft. Draft is sometimes expressed as a fraction of the starting stock thickness, called the reduction.
In addition to thickness reduction, rolling usually increases work width. This is called spreading and it tends to be most pronounced with low width-to-thickness ratios and low coefficients of friction. Some of the steel products made in a rolling mill. YEOLA Rolling is the most widely used forming process, which produces products like bloom, billet, slab, plate, strip, sheet, etc.
Friction plays an important role in rolling as it always opposes relative move- ment between two surfaces sliding against each other. At the point where workpiece enters the roll gap, the surface speed of the rolls is higher than that of the workpiece.
So, the direction of friction is in the direction of the workpiece movement and this friction force drags it into the roll gap. Material velocity is equal to the surface speed of the rolls at a plane, called the neutral plane.
Reduced labor and material handling 2. Faster, continuous production with reduced cost-per-piece 3. Greater accuracy, uniformity and consistency throughout both the individual piece and production lots 4.
The rollforming process can incorporate perforating, notching, punching, etc. Precision parts facilitate savings in labor and costs 6. Speedier assembly resulting from part uniformity and tighter tolerances 7. Far longer lengths are achievable 8. More surface-friendly for prepainted, precoated and preplated metals 9. Virtually all metals capable of cold forming can be hydroformed, including aluminum, brass, carbon and stainless steel, copper, and high strength alloys.
Since no punch is used in this method, hence, thinning of the sheet metal at the punch corner does not occur. Hydroforming is of two types; sheet forming and tube forming.
A hydroforming press operates like the upper or female die element. This consists of a pressurized forming chamber of oil, a rubber diaphragm and a wear pad. The lower or male die Advantages.
High Velocity Hydro Forming 8. YEOLA element, is replaced by a punch and ring. The punch is attached to a hydraulic piston, and the blank holder, or ring, which surrounds the punch.
The hydroforming process begins by placing a metal blank on the ring. The press is closed bringing the chamber of oil down on top of the blank. The forming chamber is pressurized with oil while the punch is raised through the ring and into the the forming chamber.
Since the female portion of this forming method is rubber, the blank is formed without the scratches associated with stamping. The diaphragm supports the entire surface of the blank. It forms the blank around the rising punch, and the blank takes on the shape of the punch. When the hydroforming cycle is complete, the pressure in the forming chamber is released and the punch is retracted from the finished part.
In hydroforming, fluid pressure acting over a flexible membrane is utilized for controlling the metal flow. Fluid pressure upto MPa is applied. The fluid pressure on the membrane forces the sheet metal against the punch more effectively. Complex shapes can be formed by this process. In tube hydroforming, tubes are bent and pressurized by high pressure fluid. Rubber forming is used in aircraft industry. Tube Hydro forming: YEOLA 2. Sheet steel is forced into a female cavity by water under pressure from a pump or by action.
Sheet steel is deformed by a male punch, which acts against the fluid under pressure. Tube hydro forming Sheet hydro forming Insem —Aug. The process is also called magnetic pulse forming, and is mainly used for swaging type operations, such as fastening fittings on the ends of tubes and crimping the terminal ends of cables.
Other applications of the process are blanking, forming, embossing, and drawing. The principle of electromagnetic forming of a tubular work piece is shown in Figure. The work piece is placed into or enveloping a coil. A high charging voltage is supplied for a short time to a bank of capacitors connected in parallel.
The amount of electrical energy stored in the 3. Electromagnetic Forming YEOLA bank can be increased either by adding capacitors to the bank or by increasing the voltage. When the charging is complete, which takes very little time, a high voltage switch triggers the stored electrical energy through the coil.
A high — intensity magnetic field is established which induces eddy currents into the conductive work piece, resulting in the establishment of another magnetic field.
The forces produced by the two magnetic fields oppose each other with the consequence, that there is a repelling force between the coil and the tubular work piece that causes permanent deformation of the work piece. Either permanent or expandable coils may be used. Since the repelling force acts on the coil as well the work, the coil itself and the insulation on it must be capable of withstanding the force, or else they will be destroyed.
The expandable coils are less costly, and are also preferred when a high energy level is needed. Electro Magnetic forming can be accomplished in any of the following three types of coils used, depending upon the operation and requirements. Figure 1. However, during the forming operation, the coil is placed surrounding the tube to be compressed.
Two types of deformations can be obtained generally in electromagnetic forming system: When the work piece is placed inside the forming coil, it is subjected to compression shrinking and its diameter decreases during the deformation process. When the work piece is placed outside the forming coil, it is subjected to expansion bulging and its diameter increases during the deformation process.
Either compression, or expansion, and even a combination of both to attain final shapes can be obtained, with a typical electromagnetic forming system for shaping hollow cylindrical objects.
The applications of electromagnetic tube compression include, shape joints between a metallic tube and an internal metallic mandrel for axial or torsional loading, friction joints between a metallic tube and a wire rope or a non-metallic internal mandrel, solid state welding between a tube and an internal mandrel of dissimilar metallic materials, tow poles, aircraft torque tubes, chassis components and dynamic compaction of many kinds of powders.
The EMF process has several advantages over conventional forming processes. Some of these advantages are common to all the high rate processes while some are unique to electromagnetic forming.
The advantages include: Improved formability. Wrinkling can be greatly eliminated. Forming process can be combined with joining and assembling even with the dissimilar components including glass, plastic, composites and other metals. Close dimensional tolerances are possible as spring back can be significantly reduced. Use of single sided dies reduces the tooling costs.
Applications of lubricants are greatly reduced or even unnecessary; so, forming can be used in clean room conditions. YEOLA 7. The process provides better reproducibility, as the current passing through the forming coils is the only variable need to be controlled for a given forming set-up. This is controlled by the amount of energy discharged.
Since there is no physical contact between the work piece and die as compared to the use of a punch in conventional forming process, the surface finish can be improved. High production rates are possible. It is an environmentally clean process as no lubricants are necessary. Electromagnetic forming is easy to apply and control, making it very suitable to be combined with conventional sheet stamping.
The practical coil can be designed to deal with the different requirements of each forming operation. The coil is firmly held and hence the work piece collapses into the die cavity due to magnetic repelling force, thus assuming die shape.
Electro Magnetic Forming All modern manufacturing industries focus on a higher economy, increased productivity and enhanced quality in their manufacturing processes. To enhance the material performance, a high energy rate forming technique is of great importance to industry, which relies on a long and trouble free forming process.
Advanced Machining Processes of Metallic Materials
High energy rate forming HERF is the shaping of materials by rapidly conveying energy to them for short time durations.
There are a number of methods of HERF, based mainly on the source of energy used for obtaining high velocities. Among these techniques, electromagnetic forming is a high-speed process, using a pulsed magnetic field to form the work piece, made of metals such as copper and aluminum alloys with high electrical conductivity, which results in increased deformation, higher hardness, reduced corrosion rate and good formability.
Reduction of weight is one of the major concerns in the automotive industry. Aluminium and its alloys have a wide range of applications, especially in the fabrication industries, aerospace, automobile and other structural applications, due to their low density and high strength to weight ratio, higher ductility and good corrosive resistance.
High energy rate forming methods are gaining popularity due to the various advantages associated with them. They overcome the limitations of conventional forming and make it possible to form metals with low formability into complex shapes. This, in turn, has high economic and environmental advantages linked due to potential weight savings in vehicles.
Advanced Machining and Manufacturing Processes
In this process the high energy released due to explosion of an explosive is utilized for forming of sheets. No punch is required. A hollow die is used. The sheet 4.
YEOLA metal is clamped on the top of the die and the cavity beneath the sheet is evacuated. The assembly is placed inside a tank filled with water. An explosive material fixed at a distance from the die is then ignited.
The explosion causes shock waves to be generated.
The peak pressure developed in the shock wave is given by: R is the stand-off distance. Compressibility of the medium and its impedance play an important role on peak pressure. If the compressibility of the medium used is lower, then the peak pressure is higher. If the density of the medium is higher, the peak pressure of the shock wave is higher. Strain rates are very high. Materials which do not loose ductility at higher strain rates can be explosively formed.
The stand off distance also determines the peak pressure during explosive forming. Steel plates upto 25 mm thickness are explosive formed. Tubes can be bulged using explosive forming. Explosive Forming The forming processes are affected by the rates of strain used. Effects of strain rates during forming: The flow stress increases with strain rates 2. The temperature of work is increases due to adiabatic heating.
Improved lubrication if lubricating film is maintained. YEOLA 4. Many difficult to form materials like Titanium and Tungsten alloys, can be deformed under high strain rates. Production rates are higher, as parts are made at a rapid rate.
Die costs are relatively lower. Tolerances can be easily maintained. Versatility of the process — it is possible to form most metals including difficult to form metals. No or minimum spring back effect on the material after the process. Production cost is low as power hammer or press is eliminated in the process. Hence it is economically justifiable. Metal spinning typically involves the forming of axisymmetric components over a rotating mandrel using rigid tools or rollers.
There are three types of metal- spinning techniques that are practiced: Spinning The tool is moved either manually or hydraulically over the mandrel to form the component, as shown in Fig. The forming operation can be performed using several passes. Manual metal spinning is typically performed at room temperature. However, elevated- temperature metal spinning is performed for components with thick sections or for alloys with low ductility.
Typical shapes that can be formed using manual metal spinning are shown in Fig. Manual spinning is only economical for low-volume production. Larger volumes can usually be produced at lower cost by power spinning or press forming. Typical components that can be produced by manual metal spinning.
Conical, cylindrical, and dome shapes are shown. The tool typically has a work face that is rounded and hardened.
Metal spinning can be performed with or without a forming mandrel. The sheet preform is usually deformed over a mandrel of a predetermined shape, but simple shapes can be spun without a mandrel.
Most ductile metals and alloys can be formed using metal spinning. Manual metal spinning is used to form Typical shapes that can be formed by manual metal spinning are shown in Fig.
Sevaral operation can be performed in one set up. Production cost low. The tooling costs and investment in capital equipment are relatively small typically, at least an order of magnitude less than a typical forging press that can effect the same operation. The setup time is shorter than for forging. The design changes in the workpiece can be made at relatively low cost. Highly skilled operators are required, because the uniformity of the formed part depends to a large degree on the skill of the operator.
The deformation loads available are much lower in manual metal spinning than in press forming.
YEOLA Flow forming is a modernized, improved advanced version of metal spinning, which is one of the oldest methods of chipless forming. The metal spinning method used a pivoted pointer to manually push a metal sheet mounted at one end of a spinning mandrel. Flow forming is a process whereby a metal blank, a disc or a hollow tube are mounted on a mandrel which rotates the material to make flow axially by one or more rollers along the rotating mandrel.
The major difference between spinning and flow forming is, in spinning, the thickness reduction is very minor and in flow forming the variation in thickness can be maintained at different places along axial directions. Flow forming means shaping a product of sheet metal, tube or drawpiece in one are more passes of the forming roll or rolls. The magnitude of wall thinning depends on the properties of the input material and the number of passes. Flow Forming is an incremental metal forming technique in which a disk or tube of metal is formed over a mandrel by one or more rollers using tremendous pressure.
The roller deforms the workpiece, forcing it against the mandrel, both axially lengthening and radially thinning it. Since the pressure exerted by the roller is highly localized and the material is incrementally formed, often there is a net savings in energy in forming over drawing processes.
Flow forming subjects the workpiece to a great deal of friction and deformation. These two factors may heat the workpiece to several hundred degrees if proper cooling fluid is not utilized. Flow forming is often used to manufacture automobile wheels. During flow forming, the workpiece is cold worked, changing its mechanical properties, so its strength becomes similar to that of forged metal.
Flow forming, also known as tube spinning, is one of the techniques closely allied to shear forming. The two types of flow forming are shown in Fig. The difference is according to the direction of material flow with respect to direction of motion of tool roller. If both are in same direction, then it is forward flow forming and if they are in opposite direction, then it is backward flow forming. Forward flow forming is suitable for long, high precision thin 6. Flow Forming YEOLA walled components.
Backward flow forming is suitable for blanks without base or internal flange. In forward spinning the roller moves away from the fixed end of the work piece, and the work metal flows in the same direction as the roller, usually toward the headstock.
The main advantage in forward spinning as compared to backward spinning is that forward spinning will overcome the problem of distortion like bell-mouthing at the free end of the blank and loss of straightness. In forward spinning closer control of length is possible because as metal is formed under the rollers it is not required to move again and any variation caused by the variable wall thickness of the per- form is continually pushed a head of rollers, eventually be- coming trim metal beyond the finished length.
The disadvantage of forward flow forming is that the Production is slower in forward spinning because the roller must transverse the finished length of the work piece. In backward flow forming the mandrel is unsupported. In backward spinning the work piece is held against a fixture on the head stock, the roller advances towards the fixed end of the work piece, work flows in the opposite direction.
The advantage of backward flow forming over forward flow forming: The preform is simpler for backward spinning because it slides over the mandrel and does not require an internal flange for clamping.
We can procedure 3 m length tube by using of mandrel. In both the flow forming processes, there is no difference in stress and strain rate. The major disadvantage of backward tube spin- ning is that backward flow forming is normally prone to non uniform dimension across the length of the product In this Process as shown in Fig.
It is usually employed to produce cylindrical components. Most modern flow forming machines employ two or three rollers and their design is more complex compared to that of spinning and shear forming machines.
The starting blank can be in the form of a sleeve or cup. Blanks can be produced by deep drawing or forging plus machining to improve the dimensional accuracy.
Advantages such as an increase in hardness due to an ability to cold work and better surface finish couples with simple tool design and tooling cost make flow forming a particularly attractive technique for the production of hydraulic cylinders, and cylindrical hollow YEOLA parts with different stepped sections. Both spinning and flow forming can also be combined to produce complex components.
By rotating mandrel process only cylindrical components can be produced.
Wong made observations in his study on flow forming of solid cylindrical billets, with different types of rollers. A flat faced roller produces a radial flange and a non orthogonal approach of nosed roller produces a bulge ahead of the roller. Traditional multi-piece designs can be formed as a single, seamless piece. Provide design versatility to produce a unique seamless profile with varying wall thicknesses.
Produce cylindrical, conical, or contoured shapes up to 47" diameter. Typical interior finishes of 15Ra without additional manufacturing steps. High material utilization from near-net shape forming process. Low production cost. Very little wastage of material. Excellent surface finishes. Accurate components. Improved strength properties. Easy cold forming of high tensile strength alloys. Production of high precision, thin walled seamless components.
When new technologies were introduced to the field of metal spinning and powered dedicated spinning machines were available, shear forming started its development in Sweden.
Shear forming was first used in Sweden and grew out as spinning. In shear forming the area of the final component is approximately equal to that of the blank and little reduction in the wall thickness occurs. Whereas with shear forming, a reduction in the wall thickness is deliberately induced. The starting workpiece can be thick walled circular or square blank.
Shear forming of thick walled sheet may require two diametrically opposite roller instead of one needed for light gauge materials. The profile shape of the final component can be concave, convex or combination of these two geometries.
A shear formed product: In shear spinning the area of the final piece is approximately equal to that of the flat sheet metal blank. The wall thickness is maintained by controlling the gap between the roller and the mandrel. In shear forming a reduction of the wall thickness occurs.
The configuration of machine used in shear forming is very similar to the conventional spinning lathe, except that it is made more robust as higher forces are generated during shear forming. Nowadays on modern machines, it is common to use both shear forming and spinning techniques on the same component. In shear forming, the required wall thickness is achieved by controlling the gap between the roller and the mandrel so that the material is displaced axially, parallel to the axis of rotation.
Since the process involves only localised deformation, much greater YEOLA deformation of the material can be achieved with lower forming forces as compared with other processes. In many cases, only a single-pass is required to produce the final component to net shape. Moreover due to work hardening, significant improvement in mechanical properties can be achieved. Operation The shear forming process is shown in Fig.
The inclined angle of the mandrel sometimes referred to as half-cone angle determines the degree of reduction normal to the surface. The greater the angle, the lesser will be the reduction of wall thickness. Principles of shear forming 1. The mandrel has the interior shape of the desired final component. A roller makes the sheet metal wrap the mandrel so that it takes its shape. On the other hand, the profile shape of the final component can be concave, convex or a combination of these two.
A shear forming machine will look very much like a conventional spinning machine, except for that it has to be much more robust to withstand the higher forces necessary to perform the shearing operation. The design of the roller must be considered carefully, because it affects the shape of the component, the wall thickness, and dimensional accuracy.
The smaller the tool nose radius, the higher the stresses and poorest thickness uniformity achieved. Good mechanical properties 2. This process used widely in the production of lightweight items. Very good surface finish. Applications Typical components produced by mechanically powered spinning machines include rocket nose cones, gas turbine engine etc.
Show all. Pages Machining of Glass Materials: An Overview Perveen, Asma et al.Wong made observations in his study on flow forming of solid cylindrical billets, with different types of rollers. The applied 7. The major disadvantage of backward tube spin- ning is that backward flow forming is normally prone to non uniform dimension across the length of the product In this Process as shown in Fig. The profile shape of the final component can be concave, convex or combination of these two geometries.
Hamed Ahmed was born in in Alexandria, Egypt. Draft is sometimes expressed as a fraction of the starting stock thickness, called the reduction.
A slab is rolled from an ingot or a bloom and has a rectangular cross section of width mm 10 in or more and thickness 40 mm 1.
Aluminium and its alloys have a wide range of applications, especially in the fabrication industries, aerospace, automobile and other structural applications, due to their low density and high strength to weight ratio, higher ductility and good corrosive resistance.
Note that the etching reaction is isotropic it proceeds equally in all directions , resulting in an undercut below the badebhau4 gmail. The shoulder serves to constrain the plasticized metal flowing around the probe.