316L Stainless Steel with Gradient Porosity Fabricated by Selective Laser Melting

To fabricate 316L stainless steel part with a pore gradient structure, the method using selective laser melting (SLM) technique is exploited. Scan tracks feature, densification, and tensile property of SLM-produced samples prepared via different scan speeds were investigated. The results show that the porosity is strongly influenced by scan speed. On this basis, a gradient changed scan speed was applied in every SLM layer for the purpose of producing a gradient porosity metal. The results indicate that the structure exhibits a gradually increased porosity and a reduced molten pool size along the gradient direction of scan speed variation. The forming mechanisms for the gradient porosity were also addressed.