Manufacturing Processes
Manufacturing Processes Manufacturing is a process that converts raw materials into products, it constitute: • The selection of raw materials • The selection of manufacturing process • The sequence of processes needed to manufacture the product Ken Youssefi Mechanical Engineering 1 Material Selection Function dictates the choice of material and shape. Function Material Process is influenced by material Shape restricts the choice of material and process. Shape Process Process interacts with shape. Material selection and process cannot be separated from the shape and the function of the product, two way interaction. Ken Youssefi Mechanical Engineering 2 Engineering Materials Materials Metals Ferrous Non-ferrous Plastics Thermoplastics Thermosets Elastomers Steel Aluminum Acrylic Phenolic Rubber Stainless steel Copper Nylon Polymide Polyurethane Die & tool steel Zinc ABS Epoxies Silicone Cast iron Brass Polyethylene Polyester Titanium Polycarbonate Tungsten PVC Ken Youssefi Mechanical Engineering 3 Engineering Materials Materials Metals Ceramics Glass Plastics Carbides Nitrides Graphite Diamond Glasses Composites Reinforced plastics Metal-Matrix Ceramic-Matrix Laminates Glass ceramics Ken Youssefi Mechanical Engineering 4 Manufacturing Processes Shaping Processes Processing Operations Surface Processing Operations Manufacturing Processes Assembly Operations Ken Youssefi Property Enhancing Processes Mechanical Engineering Permanent Joining Processes Mechanical Fastening 5 Shaping Processes Shaping Processes Casting Sand, expendable pattern, permanent mold Forming and Shaping Rolling, forging, extrusion, drawing, sheet forming, powder metallurgy, molding Machining (material removal) Ken Youssefi Mechanical Engineering Turning, milling, drilling grinding, boring, ….. 6 Manufacturing Processes Property Enhancing Processes Surface Processing Operations Ken Youssefi Heat Treatment Changing mechanical properties of a material Cleaning and surface treatments Polishing, burnishing, deburring, lapping, .. Coating and deposition process Mechanical Engineering Coating and plating 7 Assembly Operations Welding Permanent Joining Processes Brazing and soldering Adhesive bonding Assembly Operations Mechanical Fastening Threaded fasteners Rivets Ken Youssefi Mechanical Engineering 8 Casting Process • Selecting a suitable casting method. • Preparing a mold cavity of the desired shape with proper allowance for shrinkage. • Melting the metal with acceptable quality and temperature. • Pouring or forcing the metal into the cavity and providing means for the escape of air or gases. • Solidification process, must be properly designed and controlled to avoid defects. • Mold removal. • Finishing, cleaning and inspection operations. Ken Youssefi Mechanical Engineering 9 Sand Casting Metals Ken Youssefi Mechanical Engineering 10 Casting process Classifications Expendable Mold / Reusable Pattern Sand Mold Casting Plaster Mold Casting Ceramic Mold Casting Expendable Mold / Expendable Pattern Investment Casting (Lost-wax process) Evaporative Foam Casting Permanent Mold / No Pattern Permanent Mold Casting Die Casting Centrifugal Casting Ken Youssefi Mechanical Engineering 11 Casting Materials Metals most commonly used in casting are; Ken Youssefi • Iron (cast iron) • Steel • Stainless steel • Aluminum alloys • Brass, bronze and other copper alloys • Magnesium alloys • Nickel based supperalloys Mechanical Engineering 12 Large and small parts Ken Youssefi Mechanical Engineering 13 Shaping Processes Shaping Processes Casting Sand, expendable pattern, permanent mold Forming and Shaping Rolling, forging, extrusion, drawing, sheet forming, powder metallurgy, molding Machining (material removal) Ken Youssefi Mechanical Engineering Turning, milling, drilling grinding, boring, ….. 14 Manufacturing Processes – Forming Extrusion (uniform cross section) Ken Youssefi Mechanical Engineering 15 Manufacturing Processes – Forming Rolling Ken Youssefi Mechanical Engineering 16 Manufacturing Processes – Forming Forging Ken Youssefi Mechanical Engineering 17 Forged parts Machine parts Brass and steel fittins Ken Youssefi Mechanical Engineering 18 Manufacturing Processes – Forming Deep drawing Ken Youssefi Mechanical Engineering 19 Metal-Forming Process for Food and Beverage Containers How aluminum cans are made Ken Youssefi Mechanical Engineering Dept. 20 Material Removal Processes - Turning In turning operations the workpiece rotates and the cutting tool is stationary. The process produces parts that are round in shape. Parts as small as a screw with 1 mm in diameter to pistons with several inches in diameter can be machined Ken Youssefi Mechanical Engineering 21 Turning Operations Ken Youssefi Mechanical Engineering 22 Turning Operations Ken Youssefi Mechanical Engineering 23 Material Removal - Turning General view of a typical lathe, showing various components. Source: Courtesy of Heidenreich & Harbeck. Ken Youssefi Mechanical Engineering 24 Material Removal Processes - Milling Peripheral (slap) milling – the axis of the tool is parallel to the surface of the workpiece Face (End) milling, the axis of the cutter is perpendicular to the workpiece End Milling Ken Youssefi Mechanical Engineering 25 Material Removal Processes - Milling There are two basic types of knee-column milling machines Face milling – vertical milling machine Peripheral milling – horizontal milling machine Ken Youssefi Mechanical Engineering 26 Manufacturing Processes – Material Removal Drilling Grinding Broaching Ken Youssefi Mechanical Engineering 27 Manufacturing Processes Plastics Ken Youssefi • Injection Molding • Rotational Molding • Extrusion • Blow Molding • Thermoforming • Compression molding • Foam Molding Mechanical Engineering 28 Manufacturing Processes - Plastics Injection Molding Ken Youssefi Mechanical Engineering 29 Injection Molding Machine Ken Youssefi Mechanical Engineering 30 Injection Molding Parts Ken Youssefi Mechanical Engineering 31 Manufacturing Processes - Plastics Rotational Molding (large parts) Vertical wheel machine Ken Youssefi Mechanical Engineering 32 Products made by Rotational Molding process Ken Youssefi Mechanical Engineering 33 Manufacturing Processes - Plastics Blow Molding Ken Youssefi Mechanical Engineering 34 Manufacturing Processes A salt shaker and a pepper mill set has metallic and nonmetallic parts Ken Youssefi • The bodies are made of Acrylic (thermoplastic) using injection molding • The top of the salt shaker is made of sheet steel (stamping) and is plated for appearance. • The knob on top of the pepper mill is made of steel by machining (threaded on the inside) • The square rod in the pepper mill is made of steel by extrusion • The two grinder parts are made of stainless steel using powder metallurgy. Too expensive to machine or cast. Mechanical Engineering 35 Numerical Control • Numerical Control (NC) is a method of automatically operating a manufacturing machine based on a code of letters, numbers, and special characters. • The numerical data required to produce a part is provided to a machine in the form of a program, called part program or CNC program. • The program is translated into the appropriate electrical signals for input to motors that run the machine. Ken Youssefi Mechanical Engineering Department 36 Three-axis Cincinnati Hydrotel milling machine, 1952 Ken Youssefi Mechanical Engineering Department 37 Modern CNC Milling Machines Ken Youssefi Mechanical Engineering Department 38 Manufacturing Processes – Material removal Computer Numerical Control (CNC) Computer Numerical Control machines are used to fabricate complex shapes with better dimensional accuracy than conventional machining. Ken Youssefi Machining Centers Mechanical Engineering 39 CNC Machines Machining Centers, equipped with automatic tool changers, are capable of changing 90 or more tools. Can perform milling, drilling, tapping, boring… on many faces. Ken Youssefi Mechanical Engineering Department 40 CNC Machines Turning Centers are capable of executing many different types of lathe cutting operations simultaneously on a rotating part. Ken Youssefi Mechanical Engineering Department 41 Computer Numerical Control (CNC) A CNC machine is an NC machine with the added feature of an on-board computer. 1 2 A solid model of the part is created. The program path is generated by computer Ken Youssefi Mechanical Engineering Department 42 Electrical Discharge Machine - EDM Die-sinking EDM systems, the electrode (cutting tool) and workpiece are held by the machine tool. The power supply controls the electrical discharges and movement of the electrode in relation to the workpiece. During operation the workpiece is submerged in a bath of dielectric fluid (electrically nonconducting). (Die-Sinking EDM is also called Sinker, Ram-Type, Conventional, Plunge or Vertical EDM) Ken Youssefi Mechanical Engineering Department 43 Intricately detailed automobile part Ken Youssefi Mechanical Engineering Department Small gear (with insect for scale) shows a capability of EDM micromachining. 44 CNC Machines Laser Machining and Cutting (thermal cutting) The machine utilizes an intense beam of focused laser light to cut the part. Material under the beam experiences a rapid rise in temp. and is vaporized. Laser cuts with a minimum of distortion, no mechanical cutting forces. . Ken Youssefi Gas is blown into the cut to clear away molten metals, or other materials in the cutting zone. In some cases, the gas jet can be chosen to react chemically with the workpiece to produce heat and accelerate the cutting speed Mechanical Engineering Department 45 Water Jet Machining Uniform thickness parts Ken Youssefi Mechanical Engineering 46 Water Jet Machining Ken Youssefi Mechanical Engineering 47
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