Effect of Al2O3on the Process Performance of ZrO2Microspheres

Al2O3-ZrO(2)microspheres were prepared by internal gelation method. The effects of Al(3+)on the stability of solution and performance of gel spheres were studied. Al(3+)had a great influence on the stability of the solutions, and the more of the amount of Al3+, the shorter of the stabilization time. Because Al(3+)did not copolymerize with Zr(4+)during the sol-gel transformation, the strength of gel sphere added with Al(3+)was low and deformed easily as it was squeezed. The results of our experiments well verify Glasser team's speculation and conclusions. At the same time, based on the experimental results, we prepared Al2O3-ZrO(2)composite microspheres with higher content of Al(2)O(3)by controlling the pH of the solution. The change curve of viscosity with time and the stabilization time of the solution with different Al(3+)dosage were given, which could provide references for industrial mass production. Samples without hydrothermal treatment cracked severely, while the samples hydrothermally treated kept structural integrity with no cracks after calcined. Al2O3-ZrO(2)microspheres with no segregation and phase separation were prepared and alumina evenly distributed in the zirconia matrix. When the content of Al(2)O(3)was low, the tetragonal phase was stable. And the cubic phase was obtained when the content of Al(2)O(3)was more.