Towards fabrication of high-performance Al2O3 ceramics by indirect selective laser sintering based on particle packing optimization

A novel method to fabricate high-performance Al2O3 Ceramics by indirect Selective Laser Sintering (idSLS) based on particle packing optimization was reported. Al2O3 ceramics with the particle size distribution (PSD) being adjusted based on a particle packing model was prepared with the idSLS method, and the effects of PSD on the macro-performance and microstructure of the idSLSed ceramics part was investigated. Results show that an appropriate PSD of raw material is not only essential to the good SLS formability of powder bed but also contribute to the favorable sintering characteristics of the SLSed green body through an ideal particle packing. The improvement of overall properties including mechanic strength, dimensional accuracy, and surface flatness of the SLSed green body and the final parts were achieved with a fine-tuned PSD exponent. When the raw material has a PSD exponent of 0.5–0.6, the final ceramic parts showed relatively balanced comprehensive properties of bulk density >2.0 g cm−3, linear change <1.4%, fracture strength >3.97 MPa, compressive strength >5.25 MPa and surface altitude difference <148 μm.