Joining

Joining

1. welding

   • fusion
     • melting two parts
     • some cases adding a filler
   • solid state
     • no melting of the base of the metal
     • no filler
     • application of heat and/or pressure

2. arc welding

   • achieved by the heat from an electrical arc and a work piece
   • dc current for better control
   • metals are more reactive to air due to the added heat
     • can seriously degrade the mechanical propities
     • therefore the arc must be shielded

3. solid state welding

   • mating very clean surfaces
   • allow atomic bonding
   • forge and resistant welding to bond disimular metals
     • retain original properties