Tribological Properties of Nano-structured Titania

对高压低温烧结法制备的纳米晶TiO2陶瓷（粒径<100nm）和等离子烧结法制备的TiO2陶瓷进行了大范围接触载荷和室内空气滑动速度下的块环滑动磨损试验研究。块状试样为TiO2，圆环材料为轴承钢。得到了以下结果：(1)从晶粒尺寸和手性两方面对不同烧结条件下（压力0.5 ~ 1.5 gpa，温度400 ~ 500℃）制备的纳米晶TiO2的摩擦学性能进行了研究。n-TiO2的体积损失随烧结压力的增大而减小，并与样品的密度、晶粒尺寸和%金红石相有关。(2)等离子烧结法制备的TiO2陶瓷，在v=10m/s之前，磨损率随滑动速度增大而增大，但在高速时磨损率减小。它随负载单调增加。当v=0.1m/s时，TiO2陶瓷与A1203和SiC相比具有较高的耐磨性。TiO2陶瓷的摩擦学性能取决于热应力引起的脆性断裂。基于这些结果，预计纳米结构TiO2陶瓷将在高级摩擦应用中发挥重要作用。

Nanocrystalline TiO2 ceramic which was produced by sintering under high-pressure and low temperature (grain size<100nm) and TiO2 ceramic produced by plasma sintering technique were studied by the block-on-ring sliding wear tests under the wide range of contact load and the sliding velocity in room air. A block specimen was TiO2 and a ring material was bearing steel. The following results were obtained.(1) The tribological properties of nanociystalline TiO2 which was manufactured under various sintering conditions (pressure of 0.5-1.5GPa and temperature of 400-500ﾟC) were discussed from the view points of grain size and handness. The volume loss of n-TiO2 was found to decrease with sintering pressure, and was also related to the density, the grain size and the % rutile phase in the samples.(2) For TiO2 ceramic produced by plasma sintering technique, the wear rate increases with sliding velocity until v=10m/s -but then decreases at high velocity. It increases monotonously with load. TiO2 ceramic shows high wear resistance compared with A1203 and SiC under v=0.1m/s. The tribological properties of TiO2 ceramic depend on the brittle fracture caused by thermal stress. Based on these results, it is expected that nano-structured TiO2 ceramic will play an important role in advanced tribo-applications.