INFLUENCE OF SYNTHESIS CONDITIONS ON Al(OH)₃–Y(OH)₃/ZrB₂ COMPOSITE PARTICLES

Abstract

Although Zirconium diboride ( ZrB 2 ) is a desirable combination with some good properties, it is easily oxidized in the high-temperature air to impact high-temperature properties, which dwindles the applied range. In order to decrease oxidization and improve the high-temperature properties of ZrB 2 , the surface of ZrB 2 is coated with Al ( OH ) 3 – Y ( OH ) 3 to synthesize Al ( OH ) 3 – Y ( OH ) 3 / ZrB 2 composite particles. In this paper, the conditions of synthesizing Al ( OH ) 3 – Y ( OH ) 3 / ZrB 2 composite particles by the co-precipitation method are investigated. Al ( OH ) 3 – Y ( OH ) 3 / ZrB 2 composite particles are synthesized under different conditions, but the conditions of synthesizing Al ( OH ) 3 – Y ( OH ) 3 / ZrB 2 composite particles with the better coating quality require pH = 9, the appropriate concentration ( Al 3+ = 0.017 mol/L , Y 3+ = 0.01 mol/L ) of composite solution, reaction time of 60 min, titration speed of 0.05 ml/s, using the dispersant in the ZrB 2 suspension and the ultrasonic dispersion, respectively.