Manual Metal Arc welding (MMA) – Engineering
1. CircuitStep-down Transformer Converts high voltage AC to a lower voltage (220V to 80V-100V). This means the output current is greater than the input current. This is due to the primary c...
Lc Engineering Notes
Notes tagged with "lc engineering".
Oxy-Acetylene welding – Engineering
- Oxy-Acetylene is a Fusion welding process. - The joint edges are heated until the metals melt. - The molten metals join and fuse. - Oxidation is prevented by the envelope of products of co...
Submerged Arc & Resistance Seam Welding – Engineering
Submerged Arc Welding - Uses bare wire electrode. - Fed automatically from spool. - Generates electric arc to heat metal/ - Flux in powder form. - Fed using a hopper. - Electric arc melts j...
Iron Carbon Equilibrium Diagrams – Engineering Notes
Lower Critical Point - Occurs at 723°c. - Temperature change occurs. - The metal contracts dimensionally, glows less brightly and loses its magnetism. - Known as Decalescence. Upper Critic...
Heat Treatment – Engineering Notes
HardeningProcess - The piece is heated to a cherry red colour and then cooled rapidly in water oils and brine. - At the cherry red colour the steel will have undergone structural changes (F...
Polymers – Condensation & Addition Polymerization
Monomer: A monomer is a molecule of a compound which reacts with other monomers to form a polymer. Mer: A mer is a repetitive unit in a polymer. Addition Polymerisation of Ethylene (Thermop...
Polymers – General definitions
Co-Polymer: Two unlike monomers joined together in a polymer chain. E.g. Poly Vinyl Acetate Elastomer: A group of polymers consisting of linear chains that are coiled, entangled and are sub...
Polymers – Differences between Thermoplastics and Thermosetting plastics
Thermosetting Plastics Bonding - Bonding by Covalent bonds. - Primary bonds held together by strong cross links. Process: Condensation Polymerisation - Forms strong primary bonds between...
MIG & TIG Welding – Engineering notes
MIG welding - Semi automatic process. - A consumable bare wire electrode fed continuously into the weld pool through torch by spool. - An inert gas, e.g. argon, has a fluxing action and cre...
Material Testing – Engineering Notes
Material Properties Strength: The ability of a material to withstand forces of compression, tension, shear and torsion. Tensile Strength: The maximum pulling stress a material can withstan...