Compared with those in the gravity cast AlSi10Mg alloy

fine crystal grains are generated in the alloy during the laser selective melting forming process

and the coarse or needle-like Si phase in theα-Al matrix becomes mesh-like with uniform distribution.Due to the rapid cooling rate during the laser forming process

the supersaturated solid solution is formed

and the tensile strength

yield strength and elongation of the alloy reach 483 MPa

314 MPa and 6.43%

respectively.After T6 treatment

the uniform network-like Si phase is dissolved and broken to grow the irregularly shaped Si phase and the finely dispersed Si phase which are rounded and passivated

and the tensile strength and yield strength of the alloy are reduced to 208 MPa and 167 MPa

while the elongation is improved to 10.37%.