TEM INVESTIGATION OF THE MICROSTRUCTURE AND DEFECTS OF CUZR MARTENSITE - PART I - MORPHOLOGY AND TWIN SYSTEMS

The microstructure of the martensite structures in CuZr is investigate d by conventional and high resolution electron microscopy. In Part I o f these two sequential papers the details of the micro- and macrotwin arrangements are presented and discussed. The correlation between the microtwinning and the superstructure is confirmed and atomic models fo r twin interfaces, interface steps and twin tapering are derived. A co mparison with earlier findings in the isostructural B19' NiTi martensi te is made. The microtwins are (001) compound twins while the macrotwi ns are (021) Type I twins. A spear arrangement with a ((3) over bar 32 ) midrib is also observed. (C) 1998 Acta Metallurgica Inc.