Process and apparatus for welding workpiece having heat sensitive material

A welding apparatus for welding a workpiece comprising a heat sensitive material, the welding apparatus comprising:

• a welding torch comprising a contact tip;
• a power source configured to provide electrical power to the contact tip of the welding torch;
• a filler metal feeder configured to feed a filler metal extending through the contact tip towards the workpiece, wherein the workpiece comprises a heat sensitive material, and wherein an arc is generated between a tip of the filler metal and a surface of the workpiece to create a weld pool on the workpiece;
• and
• a drive configured to reciprocate the filler metal in and out of the weld pool,
• wherein the power source comprises a digital signal processor,
• wherein the digital signal processor is configured to signal the drive such that a motion of the filler metal is synchronized with a waveform of the electrical power, and
• wherein a welding parameter is adjusted such that a weld is able to be performed on the workpiece without cracking the heat sensitive material.