Abstract:
A void can be pimply doecribed op a region of bonding bots on adjacent solicit,. Ideally the mechanicalv metallurOical and chemical properties of the veld ehould be Identified to those of the solids vhich are joined0 but this hardly over happcno. A bewildering variety of welding procesoes and tech niquoo existv having different applicabilities and characteris-tics. Nevertheless0 they have a common purposev and should resemble each other at soma basic level. The important chara-cteristics of a given ',rococo and its relationship to othoro can boat be understood by considering the primary requirements of a bonding operation.
spontaneous metal to metal bonding will occur If porfect-ly clean and smooth metal surfaces are brought into intimate contacts that Isv if the atoms of one surface are broecpt to vithin atomic distances of the other. In practiced the ourfa-coo of metals in the welding shop are covered with an absorbed onldo layer and are rough. Thus intimate contact can not bo node. A voiding procesov therefore° has only to remove the chide layer00 and bring the surfaces into awe contactv for obondtobemade.......................
