The unit melting energy for a certain sheet metal is 9.5 J/mm3. The thickness of each of the two\nsheets to be spot welded is 3.5 mm. To achieve requir
The unit melting energy for a certain sheet metal is 9.5 J/mm3. The thickness of each of the two
\r\nsheets to be spot welded is 3.5 mm. To achieve required strength, it is desired to form a weld nugget
\r\nthat is 5.5 mm in diameter and 5.0 mm thick. The weld duration will be set at 0.3 sec. If it is
\r\nassumed that the electrical resistance between the surfaces is 140 micro-ohms, and that only
\r\none-third of the electrical energy generated will be used to form the weld nugget (the rest being
\r\ndissipated), determine the minimum current level required in this operation.
\r\n