The Effect Of TiO₂ On The Phase And Properties Of ZTA Ceramics

As the key component in the wire-drawing process, the choice of wire-drawing die's material is very important. ZTA ceramics has good mechanical properties such as hardness, toughness, wear-resistance, it has been considered to be the most promising material for wire-drawing die. In this article we studied ZTA(Zirconia Toughened Alumina) ceramic preparation, tested its mechanical properties which include bending strength,Kic,hardness and tribological performance,and we also studied the phase and microstructure by XRD and SEM.The results show that the optimal pressure of powder is 250Mpa. We get ZTA ceramics with poor mechanical performance at none-pressure sintering,because there is a conflict between densification and fine grains. So we try to use TiO₂ to improve the mechanical properties of ZTA.This paper exams the influence of different amount of TiO₂ on ZTA. The results demonstrate that the TiO₂ can significantly promote ZTA powder sintering ; when the TiO₂ is added at 0.5wt%, it can form solid solution with ZTA,and we can get ZTA ceramic with good mechanical performance; when the TiO₂ is added more than 1wt%,it will form ZrTiO4 with ZrO₂,reduce the performance of ZTA. The toughing mechanism to different content of t-ZrO₂ and microstructure is different, the main toughing mechanism is transformation toughing and microcrack toughing.This paper has reseached the wear properties of ZTA, the results show that the wear rate of ZTA and YG8 is between 10-5mm3/N·m and 10-4mm3/N·m, different microstructure have different wear mechanism, the friction of ZTA with fine grain is abrasive and adhensive,and the friction of ZTA with coarse grain is that particle was pull out.