Decreasing pores in a laser cladding layer with pulsed current

Abstract

A pulsed current is introduced into the traditional coaxial laser cladding process to decrease the porosity of the cladding layer. The magneto contraction force caused by pulsed current exerted on the molten pool squeezes the gas out and compensates the shrinkage during molten pool solidification. As a result the porosity of the cladding layer is decreased to an extremely low degree. Simultaneously, the grain of the cladding layer is finer with the added supercooling degree with pulsed current. The microhardness of an equiaxed zone in the cross section of a cladding layer also increases. © 2013 Chinese Optics Letters.