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A mechanical alloying process for a mixture of elemental Fe and Cr powders with the Cr compositions 20-70 at. % was investigated through the measurements of x-ray diffraction, magnetization, and 57Fe Mijssbauer spectrum. We show that magnetic studies provide more detailed information about the alloying process occurring during ball milling than the conventional diffraction techniques in this particular system. A final product after ball milling was identified as a high-temperature phase of the a solid solution, regardless of compositions studied. Powders subjected to milling in Ar gas atmosphere for 200 h were further ball milled in Nz atmosphere. The presence of N2 gas has caused a partial amorphization. The amorphous phase thus produced is found to be paramagnetic at room temperature.

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Microstructures of lath martensite that contains bcc or bct martensite crystals in FeC alloys are known to depend on the carbon content of the alloys. The effect of nitrogen content on microstructure, however, has not yet been elucidated. This study elucidates the effects of carbon and nitrogen content on microstructures via local crystallographic analysis. We found that the packet sizes are similar when the nitrogen content in the alloys are the same as the carbon content, with the packet size decreasing with increasing carbon and nitrogen content. The block and subblock thicknesses in low nitrogen lath martensite are smaller than those in low carbon lath martensite, whereas those in medium and high carbon and nitrogen lath martensites are similar. Martensite lath thickness and dislocation density in the FeN alloy laths are lower than those in the Fe C alloys laths, and the distribution of misorientation angles between adjacent the blocks and sub-blocks in FeN alloys is similar to that in FeC alloys.