Optimization of the super lateral energy in laser surface alloying of aluminum

An aluminum substrate has been alloyed with an iron and copper mixture by a laser induced plasma technique. The nanosecond pulse duration and the high plasma temperature expose the interacting materials to decalescent and recalescent regions, contributing to the formation of new chemical composites such as AlFeCu, AlFe, AlCu and CuFe. The microstructure of the alloyed surface is observed to be heterogeneous, with no crack formation and with few pores. The hardness of the laser treated surface is 103 HV, seven times harder than that of the substrate (15 HV) at a corresponding super lateral energy of 5282 mJ cm−2. (letter)