Mechanical properties of functionally graded Al-Cr-Fe alloy fabricated by sequential casting with influence of vibration

The performance of functionally graded materials is much better than materials with unchanged properties and compositions. Al-Cr-Fe alloys with different Cr concentrations were proposed for this work. Potential applications for these materials include automotive pistons. FGM was fabricated by a successive stage of the sequential casting method with mechanical vibration during the solidification. The FGM sample consists of two alloys with different chemical compositions (Al-8Si-2Fe) and (Al-2Cr-2Fe). Two types of samples were studied and compared, with and without mold vibration. The method of mechanical mold vibration, which in turn reduces the segregation and pores in the cast and refines the microstructure. The results of the XRD showed the presence of α-Al phase, Al₈₀Cr₁₃.₅Fe₆.₅, Al₁₃Cr₂, and Al₁₃Fe₄ compounds that enhance the strength of the alloy. Optical microscope images showed a difference in the microstructure at both sides of the interface between the two alloys. There is variation in the hardness values ​​due to the difference in the chemical composition of the alloys. The recorded improvement in the tensile strength was 17%, and a decrease in Compression by 1.5%.