MANUFACTURING PRACTICES By Mr.NABAL SINGH Assistant Professor, Department of Mechanical Engineering,, Jagannath University, Chaksu ,Jaipur Mail ID:- firstname.lastname@example.org
Manufacturing“The Process of Converting Raw Materials Into Products”
Manufacturing processes• Manu Factus : Latin for ‘made by hand’• Definition:• A Well organized method of converting raw material to end product• End Product: Value and utility added to output
Manufacturing a Product: General Considerations • Material Selection • Processing Methods • Final Shape and Appearance • Dimensional and Surface Finish • Economics of Tooling • Design Requirements • Safety and Environmental Concerns
Choosing Methods of ProductionUse a Selection Chart
Economic and Technolgical defination of Manufacturing
Casting ProcessesIntroduction of molten metal into a mold cavity; uponsolidification, metal conforms to the shape of the cavity. Die Casting Sand Casting
Forming and Shaping ProcessesBulk deformation processes that induce shape changesby plastic deformation under forces applied by toolsand dies. Forging Extrusion
Manufacturing Processes for Plastics• Plastics are shipped to manufacturing plants as pellets or powders and are melted just before the shaping process. Polymers melt at relatively low temperatures and are easy to handle.• Plastics can be molded and formed, as well as machined and joined, into many shapes with relative ease.
Injection Molding of Plastics
Properties of MaterialsMechanical Properties:strength, toughness, ductility, hardness, elasticity, fatigue, creep.Behavior Under Loading:tension, compression, bending, torsion, shear.Physical Properties: density, specific heat, thermalexpansion, thermal conductivity, melting point, electricaland magnetic properties.Chemical Properties:oxidation, corrosion, degradation, toxicity, flammability.
Types of MaterialsFerrous Metals: iron and steel.Nonferrous Metals and Alloys:aluminum, magnesium, copper, nickel, titanium, superalloys, beryllium, zirconium, low-melting alloys, preciousmetals.Plastics: thermoplastics, thermosets, elastomers.Ceramics: glass, graphite, diamond.Composite materials: reinforced plastics, metal-matrixand ceramic-matrix composites, honeycomb structures.
Plastics (Polymers)• Compared to metals, plastics have lower density, strength, elastic modulus, and thermal and electrical conductivity, and a higher coefficient of thermal expansion• The design of plastic parts should include considerations of their low strength and stiffness, and high thermal expansion and low resistance to temperature.