改变石英玻璃表面的硬度和弹性模量能提高脆性-延性转变的临界磨削深度,实现延性模式磨削。本文通过利用Na2CO3溶液和石英玻璃成分发生化学反应的方法对石英玻璃表面进行改性,并基于纳米压痕法和划痕法对改性后的石英玻璃表面进行分析,研究改性后石英玻璃表面的力学性质和材料去除过程。通过纳米压痕实验表明,Na2CO3溶液中的OH-和石英玻璃发生化学反应,能够在石英玻璃表面生成厚度约为12nm非SiO2成分的物质薄膜,降低了石英玻璃表面硬度和弹性模量,59,5、15%的Na2CO2溶液分别使石英玻璃表面硬度降低了4.4%和14.2%,使弹性模量分别降低了9.49/5和12.09/6,理论脆延转换临界磨削深度分别被提高了3.7和39.1%,从而提高了石英玻璃延性磨削的可操作性。
Changes in the surface hardness and elastic modulus can increase the critical grinding depth for brittle-ductile transformation to realize ductile grinding of quartz glass. The quartz glass surface was first modified by the reaction between the NazCO3 solution and the glass constituents, and then characterized using nano-indentation and nano-scratch to study the mechanical properties and the removal process of the modified surface. The nano-indentation results show that OH-in the Na2 CO3 solution reacted with the quartz glass and generated a non-silica layer of about 12nm in thickness, which thus decreased the surface hardness and elastic modulus. Specifically, the 5% Na2 CO3 solution decreased the surface hardness by 4.4% and the elastic modulus by 9.4%, and the 15 % Na2CO3 solution decreased the surface hardness by 14. 2% and elastic modulus by 12%. Thus, the critical grinding depths for brittle-ductile transformation of the quartz glass were increased by 3.7% and 39.1% respectively, andthe manipuility of ductile grinding for the quartz glass was improved.