▁limitation ▁to ▁w eld ability ▁may ▁be ▁the ▁change ▁of ▁material ▁properties ▁induced ▁by ▁the ▁w eld ing ▁process , ▁such ▁as ▁a ▁high ▁speed ▁of ▁cool ing . ▁As ▁detailed ▁discussion ▁of ▁this ▁matter ▁exceed s ▁the ▁scope ▁of ▁this ▁article , ▁the ▁reader ▁is ▁recommended ▁to ▁seek ▁more ▁information ▁in ▁the ▁appropriate ▁literature . ▁ ▁Jo ining ▁dis similar ▁materials ▁It ▁is ▁often ▁not ▁possible ▁to ▁join ▁two ▁metal ▁components ▁by ▁w eld ing , ▁i . e . ▁to ▁m elt ▁part ▁of ▁both ▁in ▁the ▁vic inity ▁of ▁the ▁joint , ▁if ▁the ▁two ▁materials ▁have ▁very ▁different ▁properties ▁from ▁their ▁al loy , ▁due ▁to ▁the ▁creation ▁of ▁brit t le , ▁inter - met all ic ▁comp ounds . ▁This ▁situation ▁cannot ▁be ▁changed , ▁even ▁by ▁electron - be am ▁he ating ▁in ▁vac u um , ▁but ▁this ▁never theless ▁makes ▁it ▁possible ▁to ▁realize ▁joint s ▁meeting ▁high ▁dem ands ▁for ▁mechanical ▁compact ness ▁and ▁that ▁are ▁perfectly ▁vac u um - t ight . ▁The ▁principal ▁approach ▁is ▁not ▁to ▁m elt ▁both ▁parts , ▁but ▁only ▁the ▁one ▁with ▁the ▁lower ▁mel ting ▁point , ▁while ▁the ▁other ▁remains ▁solid . ▁The ▁advantage ▁of ▁electron - be am ▁w eld ing ▁is ▁its ▁ability ▁to ▁local ize ▁he ating ▁to ▁a ▁precise ▁point ▁and ▁to ▁control ▁exactly ▁the ▁energy ▁needed ▁for ▁the ▁process . ▁A ▁high - v acu um ▁atmosphere ▁substantial ly ▁cont ributes ▁to ▁a ▁positive ▁result . ▁A ▁general