中文摘要：

为揭示抛光过程中SiO_2磨粒与蓝宝石的摩擦化学反应机理,结合摩擦化学理论和纳米压痕试验方法,采用有限元法模拟纳米压头压入与卸载后蓝宝石表面的应力分布情况.数值模拟结果表明：当SiO_2磨粒与蓝宝石的接触应力为5-15GPa时,发生固相反应所需活化能约为14.46kJ/mol,反应速率常数约为0.07-0.23μm/min;在摩擦化学反应过程中,SiO_2磨粒与蓝宝石的接触半径为15-21nm,其变形量为6.88-10.22nm.低载荷纳米压痕试验结果表明：忽略压头与SiO_2磨粒的硬度、几何形状等影响因素,单颗SiO_2磨粒上的作用力小于0.7 mN,其微观表面粗糙度R_t=38.19nm及R_a=3.62nm.

英文摘要：

In order to reveal the mechanism of tribochemical polishing process between sapphire wafer and silica colloid particles,contact conditions were discussed by using the tribochemistry theory and nanoindentation method.Stress distribution of sapphire wafer under unload condition was simulated by using the finite element method.When the contact stress along the sub-surface of sapphire wafer is about 5to 15 GPa,the activation energy during tribochemical reaction is approximately 14.46kJ/mol,and 0.07 to 0.23μm/min for the reaction rate.When the contact radius between silica colloid and sapphire wafer is around15 to 21nm during the tribochemistry reaction process,the deformation value is about 6.88 to 10.22 nm.The experimental results for low-loading nanoindentation and polishing process show that when the contact force is less than 0.7mN,without considering the hardness and form errors between diamond indent tip and abrasive grit,the polished sapphire wafer can achieve a smooth surface with R_t38.19 nm and R_a3.62 nm.