Al-40Sn Alloy Produced by Selective Laser Melting of Elemental Powder Mixtures

Al-40Sn alloy has been synthesized by selective laser melting (SLM) of a mixture of elemental powders. Semielliptical traces of melt are observed within the structure of the alloy, with the borders of the melted regions decorated with pores and tin inclusions. The melt traces exhibit an internal structure composed of fine crystalline regions containing columnar Al crystals that are identically oriented and separated by thin tin interlayers. As the laser power increases, the melt solidification rate decreases, increasing the size of the aluminum crystal cells and the thickness of the tin interlayers separating them. The porosity of the alloy decreases slowly with increasing power. To minimize the porosity, the parameters of the SLM process must be changed.