Effect of binder concentration ratio on the mechanical and thermal properties of silicon nitride ceramics

Silicon nitride powder is a crucial raw material for fabricating silicon nitride ceramics, with its properties exerting a decisive influence on the final product’s performance. This study investigates the influence of polyvinyl alcohol (PVA) and polyacrylic acid (PAA) as binder additives on the characteristics of the resulting ceramics. Silicon nitride powder was treated with varying concentration ratios of PVA and PAA, followed by spray granulation to produce granulated powder. Subsequent hot-pressing sintering was conducted, and the performance of the sintered silicon nitride ceramics was evaluated. The results indicate that the optimal ratio of PVA to PAA is 2 wt.% : 2 wt.%, which yielded superior comprehensive properties, including thermal conductivity, mechanical strength, hardness, and volume resistivity.