What are Joining Processes (metalworking)?
Channel: MechanicaLEi
Date: 2016-06-10

What are Joining Processes (Metalworking)?
Find out the basic definition, types and uses of how products are joined in this exciting video!  Thanks again for watching!

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Keywords:   Joining Processes metal  metal fabrication work. consists  four types: Welding Soldering Brazing Adhesive Bonding classified types namely gas welding gas welding, arc welding, resistance welding, solid state welding  Thermo-Chemical Welding.  General Welding   large number  Advantages   mechanisability near metal strength, manewerability  low cost;  easily over shadows its disadvantages likeharmfull emmisions, skilled workmanship requirement . Welding     construction  aircraft parts, automobile parts, building parts, pressure vessels, tanks, railroad equipments, ships pipelines  pretty much everything where cheap  strong metal to metal joining  required.  first type  welding  gas welding,  uses combustion heat  fuel gas mixture like oxygen  acetylene.  typical system consists  two cylinders. One with Oxygen  other with acetelyne.  flame   torch  controlled by using  control valve. filler rod  also added  increased strength.  flame reaches  temperature  3,200C  thus can melt all commercial metals to form  complete bond. Gas Welding   lot  advantages like mobility, low-cost, self-sufficiency   myriad  applications but  limited by  time taken  skill required   perfect flame, storage  gases, health problems .  second type  welding  arc welding. Here welding heat  obtained from an electric arc between an electrode   workpeice,  temperature ranges from 6000C to 7000C. Arc Welding contains three improtant welding types namely: 1. Submerged arc Welding:    arc electrode  hidden under  blanket  flux.  cuntinously fed bare metal melts  acts  filler rod. Advantages include high welding speed  smooth weld finish. Disadvantages include Flux contamination. 2. Tungsten Inert Gas (TIG) Welding.   an arc welding process where coalscence  produced by heating  workpeice with an electric arc. struck between tungsten electrode  workpeice. Advantages include better control on welding process with  drawback  high cost  equipment. 3. Metal Inert Gas (MIG) Welding: here too coalscence  achieved witha metal electrode. Advantages include faster production speed, deep penetration, with  compromise  complexity. Next  welding process  Resistance Welding: here coalscence  produced from  heat obtained from resistance offered by  workpeice to  flow  electric current   circuit    workpeice   part.  electrodes  mostly made up  copper alloys. Advantages include high rate  production, less skill requirement but  limited by high equipment cost  special surface preparation requirement.  fourth type  Welding : Solid State Welding, here Coalscence  Produced by heat obtained from mechanically induced sliding motion between rubbing surfaces. Advantages include simple operation, less time requirement no smoke witha limit on dimension  workpeice. Fifth  last  Thermo-Chemical or Thermit Welding, here coalscence  achieved by heating with superheated liquid metal  slag resulting from chemical reaction between metall oxide  Aluminium leading to an exothermic reaction. Advantages include no electricity requirement but   applicable  ferrous metal parts  heavy cross-sections. Weld Joints can be mainly classified  lap or fillet joint, but joint, edge joint, T joint  corner Joint. Weldaility  defined   capacity   metal to be welded under fabrication conditions, imposed   specific  suitably designed structure  to perform satisfactorily   structure.  last part  welding  welding defects namely: Undercut, Cracks, Porosity, Slag Inculsions  Lack  Fusion. Their main causes being improper welding, base metal  wrong welding procedures.  second type  joining processes  Adhesive Bonding    process  Joining Materials by using adhesives.  adhesives   mainly thermoplastic or thermosetting Adhesives. Advantages include high joint strength, less localised stress concentrations  low cost but  limited to temperature below 177C. Due to its ease  use its  primarily  all industrial  domestic applications. Third type  Joining Processes  soldering,   coalscende  produced by heating  rod to  suitable tempertureand by using  filler metal with  melting point below 427C.    widely   semi-conductor industry due to simplicity  low cost.  fourth type  Joining Process  Brazing, here metallic parts  joined using non ferrous filler metal   hence   areas like pipes, Heat Exchangers .  fifth  final type  joining processes  called rivetting    permanent fastening method. There  five basic types  Rivet heads: Snap or Cup head, pan head, Countersunk head, Half-counter sunk head  conical head. Rivets offer almost no stress on  workpeice due to  abscence  heat  hence require almost no skill, but require high amounts  cover plates to support  rivet.