A preliminary study on laser assisted aluminum foaming

Closed cell cellular solids defined by randomly distributed air pores in metallic matrix are a special class of light weight porous material that exhibit several unique characteristic applications in various domains of industries. Among these, in particular aluminum foam has shown a popular interest in recent years and is potentially used for many applications due to its light weight structure. In this paper laser assisted foaming experiments have been performed using CO2/Nd-YAG lasers. The results show a unidirectional and localized expansion of foam. Closed cell porous aluminum structures with different relative densities (0.39–0.33) and porosity of (61–67%) are fabricated. It is found that the beam interaction time (t int. = spot size/processing speed), the so called dwell time, plays a significant role in the evolution of the cell morphology and the expansion mechanism of foam. Preliminary results suggest that a pore size gradient and a density gradient exist in the structure as the processing condition changes. The foam has large pores and lower density for slow processing speed, in contrast to the fast processing speed with small pore size but higher density. Additionally, a few examples on laser assisted cutting of aluminum foam are also well demonstrated.