a1 School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia
a2 Division of Materials and Centre for Microscopy and Microanalysis, The University of Queensland, QLD 4047, and Australian Key Centre for Microscopy and Microanalysis, and Electron Microscope Unit, The University of Sydney, NSW 2006, Australia
a3 School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia
The morphology and distribution of high-pressure metastable phases BC8 and R8, formed in monocrystalline silicon under microindentation, were identified and assessed using transmission electron microscopy nanodiffraction analysis. It was discovered that the crystal growth inside the transformation zone was stress-dependent with large crystals in its central region. The crystal size could also be increased using higher maximum indentation loads. The BC8 and R8 phases distributed unevenly across the transformation zone, with BC8 crystals mainly in the center of the zone and smaller R8 fragments in the peripheral regions. Such phase distribution was in agreement with the theoretical residual stress analysis.
(Received June 26 2003)
(Accepted October 15 2003)