Sintering Strengthening Mechanism of MgO Sintering Additives Added in Fabricating Al2O3 Ceramics Using Binder Jetting

Abstract

Binder jetting is an emerging additive manufacturing technique suitable for fabricating Al₂O₃ ceramics. Nevertheless, the strength of parts produced via this method limits development for Al₂O₃ ceramic production. This study investigates sintering additives to enhance Al₂O₃ ceramic sintering and strength. Al₂O₃ samples with varying MgO content are fabricated. Adding a single MgO sintering additive increased Al₂O₃ resilience to 0.2 MPa. Furthermore, incorporating small grain size MgAl₂O₄ and ZrO₂ as strengthening methods is explored. The results demonstrate that while MgO-reinforced Al₂O₃ is well-suited for binder jetting, the combined use of MgAl₂O₄ and ZrO₂ significantly enhances material strength, achieving improvements of 2.7 and 6.6 times, respectively. A comparative analysis of the microstructural and surface morphological effects of MgO, MgAl₂O₄, and secondary phase content on Al₂O₃ ceramics is conducted, providing insights into the strengthening mechanisms.