材料期刊网

The surface chemistry and dispersion properties of aqueous Ti(3)AlC(2) suspension were studied in terms of hydrolysis, adsorption, electrokinetic, and rheological measurements. The Ti(3)AlC(2) particle had complex surface hydroxyl groups, such as equivalent to Ti-OH,=Al-OH, and -OTi-(OH)(2), etc. The surface charging of the Ti(3)AlC(2) particle and the ion environment of suspensions were governed by these surface groups, which thus strongly influenced the stability of Ti(3)AlC(2) suspensions. PAA dispersant was added into the Ti(3)AlC(2) suspension to depress the hydrolysis of the surface groups by the adsorption protection mechanism and to increase the stability of the suspension by the steric effect. Ti(3)AlC(2) suspensions with 2.0 dwb% PAA had an excellent stability at pH=similar to 5 and presented the characteristics of Newtonian fluid. Based on the well-dispersed suspension, dense Ti(3)AlC(2) materials were obtained by slip casting and after pressureless sintering. This work provides a feasible forming method for the engineering applications of MAX-phase ceramics, wherein complex shapes, large dimensions, or controlled microstructures are needed.