Abstract
Dense β‐Si4Al2O2N6 ceramics were obtained from α‐Si3N4, α‐Al2O3, AlN, and Y2O3 upon sintering (for 4 h at 1675°C) green bodies consolidated by an aqueous gelcasting and a conventional dry‐powder processing route. The as‐purchased AlN powder was treated with H3PO4 and Al(H2PO4)3 and dispersed in aqueous‐organic premix solution along with α‐Si3N4, α‐Al2O3, and Y2O3 powder with the help of a commercial amino alcohol‐based cationic (Dolapix A88) dispersing agent to obtain suspensions with 45–50 vol% solids loading for gelcasting purpose. The gelcat β‐Si4Al2O2N6 exhibited superior hardness (1423±6 Hv), fracture toughness (3.95±0.3 MPa·m1/2), and coefficient of thermal expansion (3.798 × 10−6/°C between 30° and 1000°C) in comparison with the ceramic consolidated by conventional dry‐powder pressing route, which exhibited only 1317±5 Hv, 3.30±0.2 MPa·m1/2 and 3.532 × 10−6/°C between 30° and 700°C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
