Investigation of the mechanical and Thermal properties of functionally graded iron aluminide

Abstract

Iron aluminide is used in many industrial applications such as valve of piston; In this work, the mechanical and thermal properties of samples made of functionally graded materials (FGMs) were studied. These specimens were manufactured by powder metallurgy, consisting of different chemical composition layers of (40–50) at% aluminum. The specimens consist of: single layers (B1, B2, B3) consisting of (40, 45, and 50) at% of aluminum and the rest of iron; FGMs (double-layer) (B4, B5, B6); and FGMs (three-layer) (B7). All results of FGM were compared with its constituent layers in all tests, including the x-ray diffraction examination, and they all showed the same phases with differences in intensity (Fe3Al, FeAl, Al13Fe4, FeAl2, Fe2Al5). From the mechanical compression test, the yield point, ultimate stress, and Young’s modulus results indicated that the FGMs have an average value compared with the layer that contained them. Thermal test: FGMs have the lowest values of thermal conductivity and thermal diffusivity compared with single-layer specimens. The specific heat of FGMs has the highest value. Thermal conductivity was recorded to range from 8.08 to 6.376 W mK−1 for single and FGM specimens, respectively; thermal diffusivity from 4.6 to 0.72 mm2 S−1; and specific heat from 1.77 to 8.84 MJ/m3K.