Análise da transição de fase de silício em “scratch tests” de alta velocidade

Abstract

When cutting brittle materials at small scales, machining in ductile regime can be obtained. Increasing the depth of cut to a critical value leads to a ductile to brittle transition in the removal process. The ductile machining is associated with phase transitions. This study investigated the change in the phase transitions when machining monocrystalline silicon with a diamond indenter. The experimental setup kinematic was that of a face turning process with no overlapping trace, with Vickers and Berkovich indenters in different orientations. The analysis of phases was performed in Raman microspectroscopy. The scratches provided evidence that even the material removal mechanism being different for the different indenters and orientations, this change does not have a significant influence on the Raman intensity ratio of amorphous phase against crystalline phase. For the diamond wire sawing process, this means that the grain shape of diamonds in the wire will not influence the surface residual phases.