Evolution of HF etching rate of borosilicate glass by friction-induced damages

Abstract

It is well-known that the HF etching of oxide glass is of critical importance for various functional and engineering applications, but the detailed etching rate and mechanisms still remain elusive. In this study, the effects of friction-induced damages on HF etching of borosilicate glass have been studied. Various friction-induced damages at borosilicate glass surfaces are achieved by rubbing against a stainless-steel ball under various conditions via a reciprocating tribometer in humid air. The experimental results show that the HF etching rate of borosilicate glass is very sensitive to the type of friction-induced damages. The decreasing of etching rate of friction-induced damages at glass surface is as follows: pristine glass > scratch zone > cracking zone > debris zone. Based on the analyses of the local structure and composition evolution, it is indicated that compared to the pristine and scratched borosilicate glass, the metal ions (such as Al3+) of borosilicate glass in the cracking zone may play important roles in reducing its HF etching rate, while the well-packaged Fe-containing wear debris at borosilicate glass surface can significantly suppress its HF etching rate. These results may help design and optimize the HF etching of oxide glasses for various functional and engineering applications.