Phase aluminum/sihcon

Iron—Aluminum and Iron—Aluminum—Silicon Alloys. The influence of aluminum on the physical and magnetic properties of iron is similar to that of silicon, ie, stabilization of the bcc phase, increased resistivity, decreased ductility, and decreased saturation magnetization, magnetocrystalline anisotropy, and magnetostriction. Whereas Si—Ee alloys are well estabHshed for electrical appHcations, the aluminum—iron alloys have not been studied commercially. However, small (up to ca 0.3%) amounts of A1 have been added to the nonoriented grades of siHcon steel, because the decrease in ductiHty is less with A1 than with Si. 

Al—FeSL Iron and siHcon, present in ptimary aluminum, may also be added to produce enriched alloys for specific purposes. The equiHbrium phase fields in the Al—Fe—Si system are shown in Figure 20 and Table 17. The intermetaUic phases have a Hmited range of composition when in equiHbrium with the aluminiiTn soHd solution. The amount of iron in soHd solution in the matrix is small, so almost aU of the iron is in the intermetaUic compounds. At low siHcon contents the iron is present as Al Fe except for about 0.01% Fe in soHd solution. As siHcon content increases, the ternary intermetaUic... 

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