Mechanical Alloying of Iron–Titanium–Carbon (Diamond) Compositions

Using methods of X-ray structural analysis, scanning electron microscopy, and Mössbauer spectroscopy, the features of the structure formation in powder systems Fe–Ti, Fe/Ti–diamond and Fe–Ti–C during mechanical alloying under the conditions of the planetary ball mill AGO-2 (energy intensity 7 W/g) were studied. It is shown that titanium and iron with limited mutual solubility under high-energy mechanical impact with a duration of 20 min interact to form an alloy of nanostructured iron and grain boundary phases of the type solid solutions Fe(Ti), Ti(Fe), and FeTi with a total 22–24 % content. In the composition of Fe-20 % Ti, titanium reaches an X-ray amorphous state, and at a titanium content above 20 wt % , the crystalline phase α -Ti is preserved in the amount of 5–10 wt % . During mechanical activation of the Fe/Ti–diamond mixture, composite particles are formed with a size in the range of 2–12 μ m, with a metal matrix structure with a diamond particle size of 0.3–1.5 μ m. It has been established that titanium accelerates the process of grain boundary and bulk interaction of iron with diamond and titanium carbide. In the studied powder compositions, a solid solution based on iron and TiC, Fe _3 C compounds is formed with their total content: Fe/40 % , Ti–diamond up to 62 % ; Fe/TiC up to 34 % . Under similar conditions in the diamond–iron mixture, grain boundary phases of the solid solution do not exceed 26 % . The formation of graphite has not been detected by X-ray diffraction.