Room temperature indentation of molybdenum disilicide

Abstract

<p>The proposed use of molybdenum disilicide (MoSi2) in gas turbines can only be properly evaluated when mechanical property information is available for all temperatures that are encompassed in this application. Because molybdenum disilicide is brittle at room temperature special testing techniques are required to obtain deformation information at this temperature. An indentation test is one method of obtaining room temperature deformation information of brittle materials. Indentations were made on two surfaces of molybdenum disilicide single crystals at room temperature. The indentations were made with a range of applied loads and the indenter was aligned in two different orientations on each surface. The deformation and fracture produced by the indentations was studied with Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). The results from these analyses are discussed in terms of the micromechanisms of deformation and fracture and related to both the hardness and changes in applied load.</p>