Manufacturing

Manufacturing

1. Definition

   • * a technical and economical process that gives shape, DIMENSIONS, properties and value
   • Measurements
   • Technical process
     • applying physical and chemical processes to alter the geometry, properties, and/ or appearance of a given starting material to make parts or products
     • includes assembly of multiple parts to make products
   • Economical process
     • transforming materials into items of greater value by means of one or more processing and/ or assembly operations
     • adds value (to the raw material)

2. Material types

   • * include metals, ceramics, polymers and their composites
   • Metals
     • usually alloys, which are composed of two or more elements, at least one of which is metallic
     • Ferrous
       • - based on iron - comprises about 75% of metal tonnage in the world
       • Steel, cast iron
     • Nonferrous
       • all other metallic elements and their alloys
       • Aluminium, copper, nickel, silver, tin, etc.
   • Ceramics
     • compounds containing metallic (or semi-metallic) and nonmetallic elements - typical nonmetallic elements are O, N and C
     • Crystalline ceramics
       • Traditional
         • Clay
       • Modern
         • Alumina (Al2O3)
     • Glasses
       • Silica (SiO2)
   • Polymers
     • - compound formed of repeating structural units called mers, whose atoms share electrons to form very large molecules - molecules usually consist of Carbon + one or more other element such as H, N, O and Cl
     • Thermoplastic
       • can be subjected to multiple heating and cooling cycles without altering the molecular structure
     • Thermosetting
       • molecules chemically transformed into a rigid structure uring curing
     • Elastomers
       • show significant elastic behaviour
   • Composites
     • Nonhomogeneous mixtures of the 3 basic types

3. Categorization of processes

   • * two broad categories of manufacturing processes discussed are shaping and assembly
   • Manufacturing processes

4. New trends

   • * new trends include environmentally conscious manufacturing, micro/ nano fabrication and additive manufacturing
   • Environmentally conscious manufacturing
     • determining the most efficient use of materials and natural resources in production, and minimizing the negative consequences on the environment
     • Associated terms
       • Green manufacturing, cleaner production, sustainable manufacturing
     • Basic approaches
       • Design products that minimize environmental impact
       • Design processes that are environmentally friendly
   • Microfabrication
     • processes that make parts and products whose feature sizes are in the micron range
     • Ink-jet printing heads, compact disks, microsensors used in automobiles
   • Nanotechnology
     • materials and products who feature sizes are in the nanometer range
     • Coatings for catalytic converter, flat screen TV monitors
   • Additive manufactuing
     • processes where the part is built layer-by-layer using the information provided by a CAD model
     • Associated terms
       • Rapid prototyping, rapid tooling, direct-digital manufacturing, stereolythography, 3D printing
     • Advantages
       • Free-form fabrication processes
         • capable of producing any required geometry, provided that the dimensions fit within the envelope of the equipment
       • Tool-less methods
         • do not require mould, dies and fixtures