Direct selective laser sintering and properties of SiC ceramics doped with Al₂O₃‒Y₂O₃

Direct selective laser sintering (DSLS) of silicon carbide (SiC) ceramics enables the rapid fabrication of complex shaped porous SiC ceramics, making it a promising additive manufacturing technology for SiC materials. However, due to the inability of SiC to maintain a stable liquid phase, challenges arise in solid state sintering via laser, including slow diffusion rates and poor bonding strength in the resulting SiC ceramics. This study investigates the effect of Al 2 O 3 ‒Y 2 O 3 liquid‐phase sintering additives on the porosity, microstructure, and physical properties of sintered bodies under different energy densities. The results show that by adjusting the energy density during the DSLS process (5.5‒13.9 J mm −2 ), porous SiC ceramics with porosities ranging from 45.57% to 56.91% can be produced. As the energy density increases from 5.5 to 13.9 J mm −2 , the compressive strength, thermal conductivity, resistivity, and specific compressive strength range from 25.00 to 181.80 MPa, 6.12 to 15.66 W m −1 K −1 , 4.17 to 34.58 Ω cm, and 17 to 97 MPa cm 3 g −1 , respectively. This study reveals the microstructural evolution and changes in the physical properties of DSLS‒SiC under the influence of Al 2 O 3 ‒Y 2 O 3 liquid‐phase sintering additives.