Pore structure and performance of porous GH4169 superalloys preparedby laser additive manufacturing

Porous GH4169 superalloy materials with the different pore structures were prepared by selective laser melting technology. The effects of pore structure on the capillary and compressive mechanical properties were investigated by scanning electron microscopy (SEM), capillary curves, and compressive stress strain curves. The results show that, the porosity of the porous superalloy specimens increases from 3.5% to 46.1% with decreasing the laser power from 285 W to 160 W. With the increase of porosity from 15.6% to 21.7%, the capillary pumping rate of the porous superalloy specimens increases from 4.44 to 6.56 mg/(s·cm³), and the capillary pumping mass decreases from 91.3 to 81.7 mg/cm³, due to the decrease of capillary force caused by the increased pore size of the porous materials. Increasing the porosity of the porous materials leads to the decrease of elastic modulus from 53 to 11 GPa and the decrease of elastic limit from 768 to 217 MPa. It also can be found that all of the porous superalloy specimens show the good resistance to the compression deformation.