Effect of TiO2–SiO2 on microstructure and mechanical characteristics of zirconium corundum abrasives by sol-gel method

Zirconium-toughened-alumina (ZTA) corundum abrasives were successfully fabricated with TiO 2 –SiO 2 co-doping by using the sol-gel method. Single particle compressive strength of the obtained ZTA corundum abrasive was evaluated upon the addition of TiO 2 –SiO 2 in different amounts. The effect of TiO 2 –SiO 2 content on the microstructure of the product was investigated. The X-ray diffraction (XRD) results illustrated that ZrO 2 is present in the α-Al 2 O 3 matrix in the form of t -ZrO 2 . Ti 2 ZrO 6 starts forming when the composition of TiO 2 –SiO 2 is 2 wt% and increases with its addition. The sample doped with 3 wt% TiO 2 –SiO 2 possessed a maximum single particle compressive strength of 45.5 N and a narrow grain size distribution,but excessive TiO 2 –SiO 2 (>3 wt%) causes an abnormal grain growth. The fracture toughness of the composites dramatically increases up to 7.89 Mpa·m 1/2 compared to the monolithic. A crack closure was obviously observed in the ZTA abrasives. The influence of the second phase on its mechanical properties was analyzed.