Microindentation device for in situ study of pressure-induced phase transformations

Abstract

In situ microscopic and spectroscopic studies of samples allow us to understand the mechanisms and measure kinetics of phase transformations in materials. We use a light microscope and a Raman microspectrometer to study phase transformations induced by contact loading. Many interesting phenomena occur in materials during indentation that can only be analyzed during indentation, in situ. By analyzing what occurs to ceramics and semiconductors in situ we can gain valuable insight into the mechanisms and kinetics of phase transformation. A microindentation device has been designed and fabricated to achieve these objectives. The microindentation device can provide the means to study pressure-induced phase transformations in real time. The basic design of the device is adaptable to several configurations, so that the device may be used in a wide variety of applications. The device consists of a piezoelectric actuator (piezoelectric translator), load cell, linear microscrew stage, translation stage containing the specimen mount and specimen holder, and diamond-tip indenter. For the first time, an indentation tester has been coupled with a Raman microspectrometer to conduct in situ studies of pressure-induced phase transformations. This article describes the design, operation, and experimentation of a microindentation device for the in situ analysis of pressure-induced phase transformations in materials.