Amorphous Fe-Zr powders have been prepared by mechanical alloying in a powder mill. The samples are characterized by x-ray diffraction, differential scanning calorimetry, and saturation magnetization measurements. The glass forming range reaches from 30 to 78 at. % Fe being much wider than for melt-spun samples. Eutectic concentrations do not play any role. The results are compared with the glass forming ability predicted by free-enthalpy diagram calculations based on the Miedema model [A. R. Miedema, Philips Tech. Rev. 36, 217 (1976)]. Amorphization by mechanical alloying seems to be a metastable equilibrium process neglecting intermetallic phases. Rather high crystallization temperatures are found in the concentration range which is not accessible by melt spinning.