Fabrication and properties of Sialon ceramics obtained by using a DMAA/MBAM gel system

Hydrolyzed AlN in traditional raw materials is not suitable for aqueous gel casting using DMAA (N,N-dimethylacrylamide) gelling agents. Therefore, a new hydrolysis-resistant AlCN was studied to replace hydrolyzed AlN. By adding the low toxicity organic monomers DMAA and MBAM (methylenebisacrylamide), the rheological properties of the slurry obtained under different conditions and the solidification and sintering properties of Sialon ceramics were studied. The results show that the best rheological properties can be obtained when the ball milling time is between 8 and 10 h and when the dispersant dose is 2%. When the ratio of DMAA to MBAM is 14:1, the flexural strength of the green body reaches a maximum of 15.29 MPa. When the sintering temperature increases from 1600 °C to 1750 °C, the density, Vickers hardness and fracture toughness of the sintered body gradually increase, reaching 3.195 g/cm 3 , 1549 HV, and 9.29 MPa m 1/2 , respectively. The flexural strength of the sintered body first increases and then decreases, reaching a maximum of 415 MPa at 1650 °C and a minimum of 303 MPa at 1750 °C.