Plastic deformation of nanophase metals

Nanophase powders of pure metals and intermetallic compounds were produced by inert gas condensation of metal vapor, and they were compacted into solid specimens in situ. The deformation behavior of these compacted foils was evaluated using microhardness indentation and TEM. Microhardness was measured at room temperature and at slightly elevated temperatures. The time and temperature dependence of the indentation size was used to estimate creep parameters. A number of single phase and two phase materials have been examined; this paper deals with pure copper, pure iron and TiAl. The nanophase compacts were all at least a factor of two harder than the material having micron-size grains. The dependence of hardness on grain size, and the effect of temperature on hardness are interpreted in terms of interface deformation processes.