When the geometry of the joint is adaptable to the process and the equipment is available, flash welding is a satisfactory method of joining molybdenum.

The principal limiting factor if the machine itself; a flash welder that can weld four square inches of steel can weld only about two square inches of molybdenum. Arc cast and powder metallurgy molybdenum products have been flash welded in air to produce welds with acceptable bend ductility. A good flash weld of stress relieved unalloyed molybdenum can be expected to develop a joint efficiency of 100%.

The advantages of flash welding molybdenum lie in the elimination of both the cast weld metal and the relatively wide heat affected zones produced during ordinary fusion welding. The speed with which flash welding can be accomplished reduces the time of exposure to oxygen. The pressure applied to the joint squeezes out the molten metal which can become contaminated with oxygen and serves to produce a weld zone without recrystallized grains.

In the flash welding of molybdenum, platen acceleration should be as rapid as possible. The amount of upset is critical. At low upsets the weld is subject to impairment by entrapped oxides and porosity; excessive upset develops a transverse fiber structure which reduces bend ductility severely. Optimum upsets are in the range 0.1-0.2 inch. The current per unit of area required for molybdenum is 2-3 times that required for low alloy steel.

Tungsten and molybdenum manufacturer-Zhengzhou Sanhui Co., Ltd has been dealing in refractory metal for over 24 years. We offer customized tungsten and molybdenum products.