Abstract:Selective Laser Melting (SLM) was used to prepare Cu-Sn alloys with optimized parameters such as laser power, scanning speed and hatching space and forming density of SLM built Cu-5%Sn, Cu-15%Sn and Cu-24.6%Sn (mass fraction) reaches 99.2%, 99.7%, and 99.7% respectively. It is found that solidification phase transformation and microstructure show non-equilibrium characteristics. α phase Cu-5%Sn alloy contains mainly α-Cu(Sn) solid solution phase, while α phase Cu-15%Sn alloy is composed of α-Cu(Sn) and δ-Cu41Sn11 phases, and β phase Cu-24.6%Sn alloy has partially decomposed to γ and δ phases. As Sn content rises from 5% to 15%, tensile strength increases from 384 MPa to 695 MPa, while fracture extension drops from 22.7% to 12%. No obvious preferred orientation exists in α Cu-Sn alloys, while texture parallel to building direction of SLM appears in β Cu-24.6%Sn alloy with strong anisotropy in tensile properties.